Trade FAQ's / Trouble Shooting Toolbox

Bosch Hot Water provides an extensive range of support for installing plumbers to assist.

Bosch builds quality product but we rely on the installing plumbers connecting the appliance to the correct water and gas supply and ensure that the unit is commissioned.

Installing manuals are located in this area of the Bosch Climate website. Click the link below.

Installation Manuals

Commissioning and user operating video content is available and can be found on the Bosch climate website at this link.

Video Support

Or can be found at the Bosch YouTube channel at this link.

YouTube Channel

We have an extensive list of customer FAQ’s / Trouble Shooting which may provide additional assistance to understand the operation of the water heater.

Customer FAQ's / Trouble Shooting

Contact Bosch on 1300 30 70 37 and request technical assistance from our team.

Contact us

Bosch offers training on the installation and operation of our water heaters at times throughout the year. We have a training centre in Melbourne and at periods throughout the year we will travel to different states and regions.

Bosch also offers online training courses.

Click here to view

Please register your interest by telephoning Bosch on 1300 307 037 or by clicking on this link and register your interest.

The installing plumber should listen to the customer feedback regarding the issues experienced. Many issues can be caused by the installation and application of the water heater and these include gas supply, water pressure, lack of commissioning of the appliance and poor location of the water heater.

The installing plumber should decide if they need to attend and inspect the units operation.

If they are confident that the installation is correct and the issue is most likely a product defect then they should advise the customer to make contact with Bosch on 1300 30 70 37 to request a warranty inspection.

Customers could also refer to the operating manuals for the product to understand the operation of the product.

User Manuals

Customers should also be referred to the Customer FAQ’s which may help to answer questions regarding the product.

Customer FAQ's

Commissioning and user operating video content is available and can be found on the Bosch climate website at this link.

Video Support

Or can be found at the Bosch YouTube channel at this link.

YouTube Channel

The warranty covers manufacturing issues related with the product and there will be no charge for parts and labour. If the issue is related to Installation faults or poor gas/water supply then charges will apply. User errors are not manufacturing faults and are not covered by the warranty.

For full warranty details please refer to our warranty document at this link.

Warranty Document

Yes. Any installation of a gas appliance requires a certificate of compliance to be provided to the householder.

Please contact your state based plumbing regulator for details on the plumber’s obligation to supply a certificate of compliance.

The gas supply line needs to be sized in accordance with AS/NZS5601.1 (Gas installation standard). Factors that need to be considered are the total Mj/h capacity of each appliance connected to the gas line (for example 21E…, 26E…, 16H…. the length of each section or junction to junction) and the type of piping used including pressure drop factor.

For natural gas, the gas meter size should be inspected to ensure the total capacity is not exceeded (typically past 6 cubic meters).

For LPG, gas regulators should be sized to pass the maximum load of all gas appliances connected to the system and the size and number of LPG cylinders calculated to ensure effective operation.

Please refer to the customer FAQ’s for additional information on LPG questions.

Click here to view

In most domestic water supplies in Australia, Bosch hot water units are suitable, however in areas with poor quality water, for example bore water, Bosch water heaters may not be suitable.

Customer operating and installation manuals include a water quality statement.

Click for Installation Manuals

Click for Warranty Conditions

Full flow water isolating valves should be installed on the cold water inlet to the appliance. Duo valves or valves with a non-return function must not to be used.

Pressure limiting or pressure reduction valves should only be installed on the cold water supply line not less than 3 meters before the appliance. Pressure limiting and pressure reduction valves should ideally be installed on the main cold supply after the water meter to ensure equal pressure for both hot and cold water.

High performance tempering valves should not be installed any closer than 1 meter to the water heater to allow adequate mixing.

Pressure limiting valves should be installed where the measured water pressure is within 30% of the maximum rating of the appliance, for example, if the maximum pressure for a water heater is 1000kpa, a pressure-limiting valve is suggested if the water pressure is above 700kpa.

However most tapware has a maximum rated pressure of 500 kpa so good plumbing practice would be to install a 500 kpa pressure limiting valve on the household cold water supply which protects all plumbing fixtures and the water heater.

The pressure limiting valve should be installed no closer than 3 meters from the appliance. They are required to be installed to protect the appliance, however, installing on the main cold water supply line after the water meter ensures hot and cold water lines are at the same pressure. This also protects other water fixtures and appliances.

The Bosch Hydropower or compact series are not suitable to be used as boosters for storage tanks and solar systems need to be able to measure the incoming water temperature and modulate their operation accordingly. Bosch Hydropower heaters do not have the ability, so they should not be used as boosters. The Bosch Highflow range of water heaters can be used as boosters because they do measure the incoming water temperature however these products cannot be purchased from Bosch.

Installation and operation manuals for Bosch water heaters can be found on the Bosch website at the link below.

Installation & Operation Manuals

A hot water heater should be installed as close as possible to the most frequently used hot water point. Other factors which may influence the installation position include the length and size of the gas supply pipe, the length of hot water pipe, position of existing doors and windows on the house. Australian Plumbing Standards include minimum clearances and distances which installers must meet.

In most situations a Certificate of Compliance is required. The installer will be aware of any additional state-dependent plumbing regulations which affect the installation.

Yes. Only suitably qualified plumber/gasfitters are permitted to install gas hot water heaters. The installing plumber/gasfitter is qualified to install and commission gas appliances, and is able to advise on the operations of the gas appliance upon completion of the installation. The installer is authorized to issue a Certificate of Compliance at the completion of the installation

In most domestic water supplies in Australia, Bosch hot water units are suitable, however in areas with poor quality water, for example bore water or non-towns water, Bosch water heaters may not be suitable. Please note that units installed on an application with poor water characteristics may result in a reduced lifespan of the appliance and voiding of the warranty.

View the link below to see our Warranty and Servicing information.

Warranty & Servicing

The temperature and flow rate fluctuations could be caused by a number of things - insufficient gas pressure, low or high water pressures, difference between cold and hot water pressures. The best way to deal with this situation is to have your Bosch Hot Water unit inspected by a suitably qualified plumber/gasfitter familiar with the Bosch water heaters. Bosch units should be commissioned on installation and regular services at intervals of every 2 years which should ensure such fluctuations do not occur.

Unlocked electronic instantaneous water heaters are compatible, although require setting alterations. We advise your plumber contact Bosch Tech Support on 1300 307 037 for further instruction.

Locked units and the Bosch mechanical range (Pilot, HydroPower and Ci Internal) are not compatible with solar applications.

Your local licensed plumber/gasfitter will be able assess your hot water requirements and suggest the appropriate model for your application while taking into account the regulations governing installation of gas appliances. Strict safety rules prevent gas appliances from certain indoor applications so it very important to have the installation and ventilation checked.

Most plumbing and trade stores have access to supply Bosch water heaters.

Contact Bosch on 1300 30 70 37 to discuss a suitable product and place of purchase or a complete supply and install option.

Alternatively, you can use our installer locator by clicking on:

Installer Locator

Please telephone the Customer Contact Centre on 1300 307 037, and the operator will assist you with the contact details of a Service Agent near you. Bosch has a comprehensive network of Authorised Service Agents around Australia, each of whom will be able to service your water heater.

Refer this link to find a service technician.

Bosch recommends a safety and service inspection at least every 2 years, and a recommended service checklist is available from Bosch which should be completed by the attending service technician.

Bosch warranty covers manufacturing defects that may occur with the appliance. Issues caused by faulty plumbing or poor installation and commissioning are not covered by the manufacturer’s warranty. In addition, regular maintenance is required, and failures caused by incorrect or lack of maintenance are not covered by warranty conditions and therefore charged to the customer.

External issues that may cause the unit to fault but are not covered by the warranty include, but not limited to, poor inlet gas supply, faulty NG meter or meter regulator, LPG gas cylinder regulator fault or incorrect type, incorrect LPG cylinder sizing, water pressure, dirty water, water outside the specified pH/quality range, incorrect installation, incompatible tapware, restrictions, and blockages.

For full conditions refer to the warranty statement found in the installation instructions or available.

Warranty Statement

Each product has a warranty which covers any manufacturing faults. The specific warranty period for your Bosch water heater can be found in the appliance Installation and Operating manual, or visit the warranty and servicing page via the link below.

Warranty & Servicing

Bosch provides customer and user manuals for each product. These can be found by following this link.

User Manuals

Video support is available on the Bosch website or the Bosch YouTube channel by following these links.

Video SupportYouTube Channel

Bosch has a Customer Service Centre that can help with your enquiries by phoning 1300 307 037.

Bosch recommends that your water heater should have a full service, safety, and performance check carried out at least every 2 years by a qualified plumber/gasfitter familiar with Bosch hot water heaters. Bosch can provide a checklist with recommended service criteria. Bosch can also recommend Bosch accredited service technicians.

Find a service technician

Bosch has a comprehensive network of Authorised Service Agents around Australia, each of whom will be able to service your water heater. Please telephone the Customer Contact Centre on 1300 307 037, and the operator will assist you with the contact details of a Service Agent near you.


Alternatively, you can use our installer locator by clicking on:

Installer Locator

Periodically inspect the water heater location to make sure there is no flammable materials or rubbish leaning on or near the appliance, and that the surrounding area offers safe access by a service technician if required. The consumer should also check that the water heater is securely fixed to the wall, the flue is free of any obstructions, that there are no heat marks or black sooting present on the wall on which the appliance is mounted.

Cover off inspection:
• Ensure no vermin; e.g. spiders, ants etc. are living in the appliance.
• Operate water heater and ensure that flame is blue (not yellow), check general condition of the appliance and wiring.
• Please note: Plumbers and gasfitters are trained and experienced in the servicing and safety inspections of the gas appliances. Servicing must be carried out only by these qualified people.

Gas safety standards and state-based regulations require that only qualified service technicians work on gas appliances. Servicing by a non-qualified person is not permitted. Please telephone the Customer Contact Centre on 1300 307 037, or use our service technician locator to assist you with the contact details of a service technician near you.

Find a service technician

Please contact Bosch Hot Water and Heating on 1300 30 70 37 to explain what problems you are experiencing with your water heater or heating system. A Customer Service representative will assist you to resolve the issue. This may include sending out a service technician on behalf of Bosch Hot Water and Heating to assess the water heater or heating system. Also please remember to keep a copy of the invoice and serial number handy when calling our Customer Service Team.

Please note that if it is agreed to have a Bosch Service Agent attend, charges will apply if the fault is not deemed to be covered by the warranty. We do recommend using a trained a Bosch Services Agent where required, as only approved agents can make a claim for costs that are covered by warranty.

Contact us Warranty & Servicing

There is not really anything a consumer can check other than to see if there may be a smell of gas around the water heater. You should ask a plumber to inspect all gas piping and connections on the household gas supply line to check for any gas leaks and seal them if found. Have the appliance be serviced to ensure correct operation which will ensure maximum energy efficiency.

Bosch external water heaters are designed to be installed outside, and where there are ants, spiders, and other small creatures, they can enter the water heater through the air intake openings in the water heater. Since the air is necessary for complete combustion of the gas, these openings cannot be blocked off. We recommend performing regular inspections around the appliance, and if the vermin infestation continues, consult with a qualified pest exterminator about possible solutions based on local conditions. The use of flammable sprays around the water heater is only advisable after the appliance is turned off and disconnected from the power supply. If you do spray around the water heater, you should wait 30 minutes before turning on appliance.

In most domestic water supplies in Australia, Bosch hot water units are suitable, however in areas with poor quality water, for example bore water or non-towns water, Bosch water heaters may not be suitable. All water heater installation and operating instructions now include the attached water quality statement.

Please note that units installed on an application with poor water characteristics may result in a reduced lifespan of the appliance and a voiding of the warranty.

Please follow this link to view our warranty statement.

Warranty Statement

Bosch Spare parts can be purchased at most plumbing trade stores or via our service agents.

Refer to this link for the suggested spare parts distributor.

Spare Parts Distributor

Please refer to this link to find spares parts technical drawings and part numbers.

Please ensure you download the correct drawing to ensure the correct part number is requested.

Spare Parts

Genuine Bosch manufactured spare parts come with a 12-month warranty.

Please discuss with the place of purchase, as parts may only be returned if deemed to be faulty once packaging has been opened.

Please be aware that there have been cases of third-party spare parts being sold. Bosch do not cover these parts, and the use of these parts may void the warranty of the appliance.

It is recommended that the boilers are serviced annually to ensure optimal performance and efficiency. This includes the testing of the water within the system to ensure the correct treatment levels, especially if there has been a leak in the heating circuit.

Find a Bosch Hydronic Heating Specialist

Yes, it is a condition of the boilers warranty that the water in the system be treated with a suitable central heating inhibitor that protects the system against corrosion and scale.

It is recommended that a power flush be conducted on the whole system every 8-10 years. It is also recommended to power flush an existing heating system prior to installing a new boiler.

Cold spots on radiator panels may indicate the need for a power flush.

If you are constantly losing pressure in the heating system you could try the following to establish the cause by:

• Checking all visible joints including radiator valves and connections for obvious signs of leakage. There needs to be consideration to potential leaks to any under-floor pipe work.
• Check that there is no water being discharged from the pressure relief valve (sometimes referred to as an overflow). For internal units his pipe usually goes from the boiler through to an outside wall and terminates outside.

In all cases it is advised to contact your boiler specialist.

Find a Hydronic Heating Specialist

There are times when a white plume or discharge can be seen coming from the flue terminal on condensing boilers. This is due to the flue gases of a high efficiency condensing boiler being cooler than that of a standard efficiency gas appliance.

The flue gases of condensing boilers exhaust at around 55 degrees C, cool quicker in the atmosphere and in certain outside temperatures cause a plume similar in effect to breath on a cold morning.

On the boilers which have a digital display, symbols may appear which could indicate a fault, or a normal function being conducted by the boiler.

Explanation of these codes and symbols can be found in our user manuals;

User Manuals

TRVs allow you to control the temperature of each room individually, thus helping to improve comfort in your home as well as saving money and energy. Most radiators will be fitted with these.

Ideally, TRVs should be well exposed and not obstructed by curtains or blocked by furniture.

This gurgling sound may be caused by a blocked condensate pipe, please contact a service technician to resolve the issue.

Find a service technician

Hydronic heating is an efficient form of heating, which uses water to deliver heat around your home.

Further information can be found by following this link:

Hydronic Heating

Or you can watch a video here:

YouTube Video

In addition to being silent and highly efficient, hydronic heating eliminates the negative effects to allergy and asthma sufferers caused by pollen and dust blowing in the air when ducted heating is used.

Bosch Hydronic Boilers are the only hydronic heating system approved by the National Asthma Council's Sensitive Choice program.

Further information can be found by following this link:

Hydronic Heating

A combi boiler is a 2 in 1 system that also provides efficient hot water to your home as well as heating.

Installing a hydronic heating system is a significant investment, that will provide you with comfort for many years. A hydronic heating system is not a one size fits all solution, rather, it is a bespoke solution designed around your home. Our Bosch Hydronic Heating Specialists are fully trained, independent installers, specialising in Bosch installations and can offer exclusive benefits to you.

Follow this link to find our list of Bosch Hydronic Heating Specialists.

Find a Bosch Hydronic Heating Specialist

Ensure that the room thermostat is working and turned up so that the requested temperature is higher than the room temperature. Make sure that it is not in an auto program setting which may override the appliance turning on. Refer to thermostat operating manual.

Check that the boiler unit is turned on and has a power supply. Refer to the user manual for operating instructions.

Manuals link

Check that the condensate pipe drain is not blocked (only applicable to condensing models). This pipe can be identified as the plastic pipe attached to the bottom of the appliance, ensure this is clear and the outlet not buried. A gurgling sound from the appliance may indicate a blocked condensate drain.

Check the appliance control panel for fault codes, or an illuminated reset light. If these are present, we recommend a service by a boiler specialist. If your appliance does present a fault code (only on appliances with a digital display), be sure to note this and pass on to the service company when making your appointment.

Find a Bosch Hydronic Heating Specialist

Bosch Hot water and heating no longer sells the Optiflow / Highflow water heater but has available spares parts and supports the warranty for these products.

Please refer to our product pages for current available hot water products.

Manuals are available for download from our website, please follow this link:

User Manuals

Bosch Optiflow/Highflow units are suitable for use with most tapware, although they do require a minimum flow rate of around 3.5 litres per minute for correct operation. Taps that are highly restrictive, or blocked, may result in the unit not igniting, or fluctuations when mixing cold water.

When a hot tap is opened, the OptiFlow / HighFlow water heater will ignite within a few seconds and begin heating the water. The additional time taken for the hot water to get to the hot tap depends on the length and size of the household’s hot water pipe between the water heater and the hot tap. The further the hot water has to travel, the longer it will take to arrive at the hot water outlet. It is recommended that hot water systems are installed closest to the outlet that is used most frequently.

There are two (2) things you can check. You can check the electricity supply to the OptiFlow / HighFlow:

• Make sure all the hot water taps are off, then turn off the power point where the appliance power is connected, and remove the power lead from the socket. Wait for at least 30 seconds before plugging into the power point again and switching on the power. Wait for at least one (1) more minute while the OptiFlow / HighFlow carries out its own diagnostic check, (the Optiflow unit fan will operate for 20 seconds) then turn on a hot water tap and test for hot water.

You can also verify that the gas supply is available:

• Check other gas appliances to see if they are operating correctly (gas cook top, gas heating appliance). For customers using natural gas please check the gas meter assembly ensuring that the main valve is open. Contact your local gas authority if no gas is available or the gas valve is turned off as there may be a reason. For customers using LPG, check that the gas cylinders are heavy or full. Ensure that the supply valve is open. Check Elgas website for checking cylinders.

The FAQ section has a section on LPG questions.

Please refer to these questions as they may help to evaluate the situation.

Yes. The power should remain on at all times. In cold climate areas the power also provides frost protection for the appliance. If the water heater will not be used for extended periods, it is recommended that the system be drained of water.

Plumbing regulations allow only minor adjustments to the outlet temperature of a locked 50°C OptiFlow / HighFlow heater. The outlet temperature at the nearest sanitary fixture must not exceed 50°C after the minor temperature adjustment. This adjustment must be performed by a licensed plumber using a temperature selector pad or OptiFlow Controller.

As per Australian Plumbing Standards, the maximum hot water temperature delivered to bathrooms and ensuites must not exceed 50°C. Appliances such as the Bosch Optiflow and HighFlow have models that are pre-set to 50°C which conforms to the standard, removing the need of additional valves required to temper water at 50°C.

Standard Bosch OptiFlow / HighFlow water heaters are factory set to supply water at a temperature of 55°C. The temperature of the hot water delivered by these units can be increased to as high as 70°C, which means that a tempering valve may need to be installed in the house for safety.

Bosch also has available OptiFlow / HighFlow models that are locked at a maximum delivery temperature of 50°C which means that a tempering valve is not required to be installed in the house. These locked water heaters cannot be unlocked to deliver higher temperature hot water.

The noise you can hear is the water valve readjusting its position in response to a change in the ambient temperature.

The unit makes this automatic adjustment in preparation for the next time that that a tap is opened to deliver hot water.

This adjustment prepares the unit to generate hot water with maximum responsiveness and efficiency.

If the customer has a Bosch controller connected then the display should indicate the current fault, refer to the product manual to understand the current fault.

Download the product manual from this link.

Product Manuals

If the Optiflow has a Bluetooth function then you can connect to the appliance via the Bosch Water App to establish the current fault code.

See how to connect the app through this link.

Click here to watch

To reset the Optiflow and HighFlow unit you should turn off the water to the appliance and then turn off the power to the appliance, remove the power lead from the power point, wait 30 seconds and then plug back into the power point.

When the HighFlow unit is turned back on you may hear a small sound.

When the Optiflow unit is turned back on the fan will operate for approx. 20 seconds as an initial purging.

If you doubt the power supply then check the power point by operating a different tool / appliance or plug the appliance into an alternative power point using an extension lead.

Optiflow Water Heaters

To fully reset a Bosch Optiflow unit you need an Optiflow controller.

Many installations don’t have a controller installed so customer will need to rely on a technician to attend and inspect the water heaters with a Bosch optiflow controller.

Listed fault codes are available in the installation and operating manual.

This can be downloaded from the web site at this link.

User Manuals

There are various reasons for hot water fluctuations. If the fluctuations are caused by a fault of the appliance, then this would be covered if within the warranty period. External issues such as gas or water supply/flow would not be covered.

Checks that can be made prior to the booking of a service call are to make sure that tap outlets and aerators are not blocked and providing adequate water flow. It is important that there is enough water flow for correct operation of the unit.

The warranty offered by Bosch covers any manufacturing defects in the product as detailed in the attached warranty statement.

Warranty Statement

The warranty doesn’t cover faults external to the product such as water, gas and power supply to the unit or other performance issues caused by external factors.

If the unit is not covered by warranty, then there will be a charge for the inspection by the service agent. We do recommend using a trained a Bosch Services Agent where required, as only approved agents can make a claim for costs that are covered by warranty.

The warranty period for the Optiflow / Highflow unit is 3 years parts and labour and 12 year part only on the heat exchanger.

Please refer to our full warranty conditions in the customer and installation manual or refer to this link to download our warranty terms and conditions.

Warranty Terms and Conditions

After an LPG cylinder is replaced, air may have entered the gas supply pipe that will require purging.

First ensure that the gas cylinder is turned on, and valves and power supply to the appliance are also on.

If the unit had initially failed, then it may have gone into an error lockout. To first clear this so it attempts ignition again, turn off the power supply to the unit and unplug the appliance for about 10 seconds. Refit the plug and turn the power back on, if the fan starts running, wait for the fan to stop before running the hot water.

To purge the gas line, open the closest hot tap to the appliance and let run for 5 seconds and turn off to avoid the appliance faulting if it doesn’t ignite. Repeat this process until hot water starts to be delivered.

If the unit still fails a service is recommended.

Please telephone the Customer Contact Centre on 1300 307 037, and the operator will assist you with troubleshooting or the contact details of a Service Agent near you. Bosch has a comprehensive network of Authorised Service Agents around Australia, each of whom will be able to service your water heater. Bosch recommends a safety and service inspection at least every 2 years, and a recommended service checklist is available from Bosch which should be completed by the attending service technician.

Bosch Site Video Support

Customer user manuals can be downloaded at this link.

User Manuals

To connect to the Bosch Optiflow Bluetooth appliance please refer to the instructions contained in the installation manual or refer to the video help.

VIdeo Help

Any licensed plumber or gasfitter can service the Bosch Optiflow and Highflow appliances. It is recommended that the attending service technician has access to a compatible temperature controller which will assist in diagnosis and appliance performance settings.

If the appliance is under warranty, then a Bosch Service agent is required to attend.

Please contact our Customer Service Team on 1300 307 037 who can help with booking a warranty service or advise on your nearest Service Agent for general servicing of the appliance.

These can be purchased where Bosch spares parts are sold.

Refer to this link for spare parts sales.

Spare Parts

Hydropower refers to the electric power generated by the hydrogenator of the appliance. The hydrogenator produces a small electric voltage to provide power to the ignition system to ignite the appliance. This removes the need for mains power.

No external power is needed. The low voltage electricity generated by the hydrogenerator provides the power required to ignite the appliance.

Yes. The Hydro models require a minimum flow rate of 3.5 litres per minute to operate the hydrogenerator, and to activate the mechanical controls. Inadequate water flow may result in the appliance to not turn on or a fluctuation of water temperature. Ensure all tap filters or aerators are free of blockages and provide enough flow for operation.

Manuals are available for download from our website, please follow this link:

User Manuals

Instructions for the operation and temperature adjustment can be found in the user manual. A download for the manual can be found at this link;

User Manuals

Video support on adjusting the temperature can be found on our website here;

Video Support

Or from our YouTube channel here;

Bosch YouTube Channel

The external Hydropower models can be installed in locations where occasional frost occurs for short periods of time, however in these locations an Exogel valve is required to be fitted to provide adequate frost protection. If the unit is not to be used for long periods of time it is advisable that the water supply be turned off to the appliance, and the water drained from the unit.

Exogel part number: H707060151

Instructions to remove the front cover and access the controls are shown in our video support which can be found here;

Video Support

Or from our YouTube channel found here;

YouTube Video

Please telephone the Customer Contact Centre on 1300 307 037, and the operator will assist you with troubleshooting or the contact details of a Service Agent near you. Bosch has a comprehensive network of Authorised Service Agents around Australia, each of whom will be able to service your water heater. Bosch recommends a safety and service inspection at least every 2 years.

Customer user manuals can be downloaded at this link:

User Manuals

This can indicate issues with the combustion of the gas which means it is not burning correctly.

Refer to the trouble shooting section for additional information on this topic and the question regarding vermin.

We suggest that the appliance be inspected and service by a licensed plumber.

Bosch external water heaters are designed to be installed outside, and where there are ants, spiders, and other small creatures, they can enter the water heater through the air intake openings in the water heater. Since the air is necessary for complete combustion of the gas, these openings cannot be blocked off. We recommend performing regular inspections around the appliance, and if the vermin infestation continues, consult with a qualified pest exterminator about possible solutions based on local conditions. The use of flammable sprays around the water heater is only advisable after the appliance is turned off and disconnected from the power supply. If you do spray around the water heater, you should wait 15 minutes before turning on appliance.

No, controllers cannot be attached to Hydropower model.

When a hot tap is opened, the water heater will ignite within a second or two and begin heating the water. The additional time taken for the hot water to get to the hot tap depends on the length and size of the household’s hot water pipe between the water heater and the hot tap.

If you feel that the water is taking too long, or longer than normal, then a service may be of benefit. We recommend that a service be conducted every 2 years to maintain optimal performance.

It is recommended that the water heater is installed as close as practical to the most frequently used hot tap.

The hydropower water heater is a continuous flow water heater and will supply constant hot water as it has no storage tanks and heats on demand.

If the unit is not supplying adequate hot water, then we suggest a service of the product.

Yes. Tempering valves can be used with Hydropower models. High performance tempering valves are always suggested to provide complete and safe mixing.

The plumber should set up the tempering valve to suit the application.

The warranty period for the external hydropower unit is 2 years parts and labour and 10 year part only on the heat exchanger.

Please refer to our full warranty conditions in the customer and installation manual or refer to this link to download our warranty terms and conditions.

Warranty and Servicing Information

No, this product cannot be used as a solar booster.

Connected to the pipework of the appliance should be two isolation valves, one for water and one for gas. Turn off both of these valves and contact a licensed technician.

Manuals are available for download from our website, please follow this link:

User Manuals

A video showing how to light the pilot can be found here;

Click here to watch

Operating instructions can be found in the installation and operating manual. Please click on this link.

User Manuals

Instructions for adjusting the temperature delivered by the water heater can be found in the user manual which can be obtained by following this link;

User Manuals

There is also an instructional video of adjusting the temperature that can be found by following this link;

YouTube Channel

The water flow passing through the unit is what operates the burner to heat the water. It is important that there is adequate flow of water for correct operation. The hot water outlets should be checked for blockages of their filters or aerators and that there is sufficient water flow.

It is recommended, particularly in the shower, to start with opening the hot water fully ensuring enough flow, then using the cold water tap only to regulate the temperature, leaving the hot tap fully open. If you have a single handled ‘mixer’ tap, then start with the lever fully open in the hot position, then once hot water is delivered, turn towards the cold to get the desired temperature, ensuring the lever remains in the fully open position. If the water temperature supplied by the water heater is set too high, this may potentially create fluctuation due to the amount of cold required to cool it down to a usable temperature.

If you have the 10P model, please refer to our temperature adjustment video to find out how to set the appliance at a lower temperature which will also add to the efficiency of the appliance. Follow the link below. For the 16P model, the temperature is thermostatically controlled and should be set during the commissioning process upon installation.

YouTube Video

Further information can be found in the user manual that can be downloaded by following this link;

User Manuals

When a hot tap is opened, the water will begin heating the water as it passes through the appliance. The additional time taken for the hot water to get to the hot tap depends on the length and size of the household’s hot water pipe between the water heater and the hot tap.

It is recommended that the appliance be installed as close as practical to the most frequently used hot tap.

The pilot model water heater is a continuous flow water heater and will supply constant hot water as it has no storage tanks and heats on demand.

If the unit is not supplying adequate hot water, then we suggest a service of the product.

Ensure the correct procedure for relighting the pilot is be followed. Watch the pilot lighting video by following this link;

YouTube Video

If the pilot still does not stay on a service call is required.

It is recommended to have the appliance serviced every 2 years. Please call the Bosch Contact Centre on 1300 30 70 37 who will be able to recommend a suitably qualified service technician who will be able to attend your water heater.

If the pilot light keeps going out, a service call is required.

It is recommended to have the appliance serviced every 2 years. Please call the Bosch Contact Centre on 1300 30 70 37 who will be able to recommend a suitably qualified service technician who will be able to attend your water heater.

Information regarding service agents and a locator can be found by following this link

Click here to view

Please telephone the Customer Contact Centre on 1300 307 037, and the operator will assist you with troubleshooting or the contact details of a Service Agent near you. Bosch has a comprehensive network of Authorised Service Agents around Australia, each of whom will be able to service your water heater. Bosch recommends a safety and service inspection at least every 2 years, and a recommended service checklist is available from Bosch which should be completed by the attending service technician.

Please also refer to our video support regarding correct operation of the pilot model.

YouTube Channel Bosch Site

Customer user manuals can be downloaded at this link.

User Manuals

To get the most out of your appliance, Bosch recommends that an appliance service and safety inspection is conducted every 2 years. Please call the Bosch Contact Centre on 1300 30 70 37 who will be able to recommend a suitably qualified service technician who will be able to attend your water heater.

Refer to this link to find a suitable qualified service technician.

Find a service technician

A 9kg gas cylinder will not supply enough gas to heat the water.

Please refer the LPG section in the FAQ’s

This has important information regarding LPG and correct cylinder sizing.

The warranty on a domestic installation of the Pilot Range is 2 years parts and labour.

The heat exchanger carries a 10 year part only warranty.

More warranty information can be found here;

Warranty Information

Bosch external water heaters are designed to be installed outside, and where there are ants, spiders, and other small creatures, they can enter the water heater through the air intake openings in the water heater. Since the air is necessary for complete combustion of the gas, these openings cannot be blocked off. We recommend performing regular inspections around the appliance, and if the vermin infestation continues, consult with a qualified pest exterminator about possible solutions based on local conditions. The use of flammable sprays around the water heater is only advisable after the appliance is turned off and disconnected from the power supply. If you do spray around the water heater, you should wait 15 minutes before turning on appliance.

This can indicate issues with the combustion of the gas which means it is not burning correctly.

Refer to the trouble shooting section for additional information on this topic and the question regarding vermin.

We suggest that the appliance be inspected and service by a licensed plumber.

No, this product cannot be used as a solar booster.

No, controllers cannot be attached to Pilot Models.

The Pilot Range models can be installed in locations where occasional frost occurs for short periods of time, however in these locations an Exogel valve is required to be fitted to provide adequate frost protection. If the unit is not to be used for long periods of time it is advisable that the water supply be turned off to the appliance, and the water drained from the unit.

Exogel part number: H707060151

Yes. Tempering valves can be used with Pilot models. High performance tempering valves are always suggested to provide complete and safe mixing.

Connected to the pipework of the appliance should be two isolation valves, one for water and one for gas. Turn off both valves and contact a licensed technician.

Manuals are available for download from our website, please follow this link:

User Manuals

Hydropower refers to the electric power generated by the hydrogenator of the appliance. The hydrogenator produces a small electric voltage to provide power to the ignition system to ignite the appliance. This removes the need for mains power.

No external power is needed. The low voltage electricity generated by the hydrogenerator provides the power required to ignite the appliance.

No 240 volt power supply required.

Yes. The Hydro models require a minimum flow rate of 3.5 litres per minute to operate the hydrogenerator, and to activate the mechanical controls. Inadequate water flow may result in the appliance to not turn on or a fluctuation of water temperature. Ensure all tap filters or aerators are free of blockages and provide enough flow for operation.

Instructions for the operation and temperature adjustment can be found in the user manual. A download for the manual can be found at this link;

Installation Manuals

Video support on adjusting the temperature can be found on our website here.

Video Support

Or from our YouTube channel here;

YouTube Video

The Internal Compact is designed to be installed indoors. The unit is not a room sealed appliance, therefore installing in a bathroom or toilet is strictly prohibited. The location should be assessed by your licensed plumber to ensure it is suitable.

Please refer to the installation manual for further details;

Installation Manual

Fluing needs to be installed vertically.

Single and twin skin flue can be installed based on the installation specifics.

Bosch doesn’t sell the fluing but they can be purchased from plumbing suppliers.

The internal compact may require a flue adaptor which can be purchased from plumbing suppliers.

Fluing needs to be installed vertically to ensure flue gases escape correctly. A flue safety switch is installed which could possibly trip if the flue gasses cannot escape correctly causing the unit to shut down safely.

Please refer to these additional fluing instructions that can be found at this link.

Fluing Instructions (PDF, 0.4 MB)

Please refer to the installation manual for fluing instructions at this link.

Installation Manual

Yes, the fluing needs to be installed vertically.

The installation manual has details regarding the fluing and prohibited installations.

A technical information sheet can be found at this link.

Technical Information (PDF, 0.4 MB)

Yes the Internal Compact hot water unit requires a minimum 1.8 metres of vertical flue to be installed.

Please refer to these additional fluing instructions that can be found at this link.

Fluing Instructions (PDF, 0.4 MB)

The Internal Compact product has a flue which is supplied and installed by the installing plumber.

If the flue is not sealed correctly as it penetrates the roof, or the flue cowl is not weatherproof then rain water may enter the water heater and effect the operation of the unit.

This is most likely not a Bosch product fault so the customer should contact the installing plumber to review the installation of the flue system.

The outer casing of the appliance contains openings for air to be drawn in for combustion, and for the exhaust of the combustion gases, which cannot be blocked off. Vermin such as ants or spiders may enter the appliance through these openings which may create blockages within the burner. It is advisable to perform regular inspections of the appliance. Spraying around the appliance can be performed but only advisable with the appliance turned off and not used for 30 minutes afterward. If infestation occurs a consultation with a qualified pest inspector should be made about possible solutions based on local conditions.

The Hydropower product has a safety time to allow ignition and safe operation. If this short period expires without ignition, then a re-ignition attempt will be required. The hot water tap should be turned off, and then on again.

If the heater still fails to ignite, please call the Bosch Contact Centre on 1300 30 70 37 who will be able to recommend a suitably qualified service technician who will be able to attend your water heater.

Customers should refer to the customer and installation manual for the appliance.

Please follow this link to download the manual for the Ci internal unit.

This has a comprehensive list of fault codes.

Installation Manuals

Common fault codes are;

EA = ignition failure

Check gas supply is on at unit and to house, check other gas appliances.

FO = Power button pressed with hot tap open

Close the tap, this will reset the fault, and open again.

Please telephone the Customer Contact Centre on 1300 307 037, and the operator will assist you with the contact details of a Service Agent near you. Bosch has a comprehensive network of Authorised Service Agents around Australia, each of whom will be able to service your water heater. Bosch recommends a safety and service inspection at least every 2 years, and a recommended service checklist is available from Bosch which should be completed by the attending service technician.

Please refer to the installation and customer instructions for operating details and temperature adjustments.

Installation Manuals

Please refer to the Bosch YouTube channel or Video support on the Bosch climate web site for an explanation of the temperature controls and adjustments.

Bosch Youtube Video Bosch Climate Video Support

No, controllers cannot be attached to the Internal Compact.

When a hot tap is opened, the water heater will ignite within a second or two and begin heating the water. The additional time taken for the hot water to get to the hot tap depends on the length and size of the household’s hot water pipe between the water heater and the hot tap

Yes. Tempering valves can be used with Hydropower models. High performance tempering valves are always suggested to provide complete and safe mixing.

All gas appliances should be installed and commissioned to ensure correct operation.

Please follow this link to explain how to commission a Ci internal compact unit.

Click here to watch

Or please refer to the installation manual for product details and explanation of the commissioning procedure.

Installation Manuals

Connected to the pipework of the appliance should be two isolation valves, one for water and one for gas. Turn off both valves and contact a licensed technician.

Instructions on how to set the time and date can be found in the installation manual, referring to the Bosch you tube channel or the online self help video. Setting the Date can be found in the “Set” section of the controller.

View the How to Video here.

Instructions for operating the heat pump can be found in the manual which can be downloaded by following this link;

User Manual

Video support for programming the heat pump can be found on our website or YouTube channel;

Video Support YouTube Video

It is recommended to run the heat pump in manual, however if you plan to operate it on a timed program, ensure adequate time is allowed for hot water recovery. Please refer to the manual for recovery times.

Recovery rates for heat pump are listed in the installation manual but will take longer than electric tanks due to the energy efficiency of the system. The outside temperature will influence the recovery rates greatly and in winter a recovery rate of 8 to 12 hours is possible normal.

If the heat pump has a fault with the refrigeration system then it is possible to operate the heating element only.

This attached document details how to activate the backup function in the event of failure.

Heat Pump HEA Document (PDF, 0.5 MB)

When in operation the heat pump produces condensation that should drain through the drainpipe at the rear of the appliance. If the appliance is not levelled correctly, the condensation may drain from other areas.

The tank is also fitted with a PTR Valve that will allow a small amount of water to drain from the tank during the heating process.

It is recommended that the heat pump be serviced every 2 years. Areas with hard water characteristics may require a more frequent servicing interval. Please phone our Customer Service Team on 1300 307 037 who can advise you on your nearest service agent.

The error code can be reset by pushing and holding the ‘ok’ button for 3 seconds. The unit will then restart and attempt to heat the water. If the problem reoccurs please contact our Customer Support Team on 1300307037 who can advise you of your nearest service agent, or alternatively you can follow this link;

Find a Service Technician

Yes, certain water quality can have an effect on the performance and life expectancy of the heat pump. Areas with a high pH or hardness level will benefit to have water treatment in place to prevent scale build up. These areas may also require an annual descale performed on the appliance. Areas with low pH or using rainwater may benefit in a neutraliser being fitted to prevent corrosion.

Local water characteristics may have an impact on the warranty of the appliance. Warranty conditions can be found by following this link.

Warranty & Servicing Information

The heat pump performs a weekly disinfection of the tank by raising and maintaining the whole tank temperature to above 60C for 35 minutes. This will be indicated by LEG appearing on the control screen.

The unit will remain in the LEG function until it has achieved maintaining the temperature for a constant 35 minutes. If the appliance is remaining in LEG mode, this may indicate a leak in the hot water line. If this is suspected, turn the water supply off to the appliance overnight which will allow the heat pump to maintain the temperature. In these cases, please contact your local plumber, or call our Customer Service Team on 1300 307 037 who can advise you on your nearest agent.

The Bosch heat pump appliance has a Legionella function which means that the tank temperature needs to be raised to 60c and held for 35 minutes to prevent legionella forming once a week.

If the unit appears to showing “LEG” on the screen it may mean that the units cannot complete this function.

Customers should consider some of the following, reset the appliance, turn of the water overnight in case of water leaks on the hot water piping, ensure the internal pump speed is set to Speed 3 or arranging for a general service of the product.

Yes, if the cylinder runs out of gas during operation of the water heater or boiler, or the unit has made repeated attempts to ignite with no available gas, they may go into a safety lockout and require resetting.

The size of cylinders required will depend on the installation and gas appliances to be used.

9kg ‘BBQ’ cylinders are not suitable for use with Bosch hot water or heating systems.

Typically, a standard house application will require 45kg cylinders, please download this document for further information on the correct sizing of gas cylinders.

Download LPG Cylinder Information (PDF, 0.4 MB)

An auto changeover system is preferable as this ensures you have continuous supply of LP gas. You must still regularly check to see the valve has automatically changed, and arrange for the empty cylinder(s) to be filled. Please discuss this with your LPG supplier.

After an LPG cylinder is replaced, air may have entered the gas supply pipe that will require purging.

First ensure that the gas cylinder is turned on, and valves and power supply to the appliance are also on.

If the unit had initially failed, then it may have gone into an error lockout. To first clear this so it attempts ignition again, turn off the power supply to the unit and unplug the appliance for about 10 seconds. Refit the plug and turn the power back on, if the fan starts running, wait for the fan to stop before running the hot water.

To purge the gas line, open the closest hot tap to the appliance and let run for 5 seconds and turn off to avoid the appliance faulting if it doesn’t ignite. Repeat this process until hot water starts to be delivered.

If the unit still fails a service is recommended. Please contact our Customer Service Team on 1300 307 037 who can advise you on your nearest service agent, alternatively you can use the link below.

Find a Service Technician