Troubleshoot Therm 660 EF/EFO

Unit does not attempt to ignite when water is running

• Check for reversed plumbing or crossed pipes.
• Check the water drain valve filter.

Unit attempts to ignite but fails

• Reset unit and try again. There may be air in the gas line.
• Have a professional check the gas supply pressure.

Hot water is not available when a fixture is opened

• Are the gas and water supply valves fully open?
• Is the water supply cut off?
• Is the hot water fixture sufficiently open?
• Is the gas being cut off by the gas meter? (Can other gas devices such as stoves be used?)
• (For LP) Is there enough gas in the tank? (Can other gas devices such as stoves be used?)
• Is the water drain valve filter clogged?
• (Using the remote controller) Is the power button turned on?

No water is available when a fixture is opened

• Is the water supply cut off?
• Is the heater frozen?

The hot water is not the correct temperature

• Is the hot water fixture sufficiently open?

Water takes time to become hot when turning the hot water fixture

• Have you allowed enough time for the cold water in the pipes to drain out?

Water is too hot

• Is the water supply valve fully open?
• (Using the remote controller) Is the water temperature setting appropriate?
• If the water supply temperature is high, it is possible for the temperature to be higher than the temperature set on the remote controller.
• If only a small amount of hot water is demanded, it is possible for the temperature to be higher than the temperature set on the remote controller.

Water is not hot enough

• Is the gas supply valve fully open?
• (Using the remote controller) Is the water temperature setting appropriate?
• If the amount of hot water required is very high, it is possible for the temperature to be lower than the temperature set on the remote controller.
• Decrease the amount of hot water passing through the unit and the temperature should stabilize.

The water is cold when only a single fixture is open

• The unit will not heat the water if the flow rate is less than 0.5 GPM (2L/ min.). Open the fixture more or open other fixtures so that a greater flow passes through the unit, and the unit should begin heating again.

Fluctuations in hot water temperatures

• Clean the water filter of any debris.
• (Using the remote controller) Set water temperature at 115°F (48°C) to 120°F (50°C). This will allow you to use a higher flow of hot water thus meeting the minimum flow requirement of 0.5 GPM (2L/min.)