In order to troubleshoot your tankless water heater, it helps to be aware of some of the more common causes of problems. Even if you own a "smart" tankless water heater such as a Bosch, Rinnai, Paloma, or Noritz, this troubleshooting guide will help you.

Common Tankless Hot Water Heater Problems

Hot water not being instant is one of the more common complaints of tankless water heater owners. Unfortunately, this does not mean there is something wrong with your water heater in most cases, as tankless water heaters are not designed to provide immediate hot water. The only exception is if your water heater has a buffer tank or a recirculation pump. It will take time for the hot water to go from the heater, through the tips, and to the fixture. The upside is a lack of immediate hot water does not mean your water heater needs to be fixed.

Other common complaints of tankless hot water heaters (that can be fixed) include:

  • No hot water
  • Temperature issue (the water is too hot or too cold)
  • Burner problems (the burner is noisy or does not ignite)
  • Lack of water pressure

No Hot Water: If you do not have any hot water, the problem could be the burner, the pipes, or something in the electrical system. You can check to make sure the burner is sparking and the pipes are not frozen. You should also make sure the shut-off valve is not closed.

Temperature Issue: It is entirely possible the temperature of the water just needs to be adjusted on the water heater. If the temperature is set right, check to make sure the fixture you are using is not clogged and the burner is igniting. Frozen pipes or sediment buildup in the pipes can also cause this problem.

Burner Problems: Make sure the power and gas supply to the water heater is actually on. Does the gas valve open? Is there a bleed in the line? Have you checked the fan for any debris? Is there an excessive amount of condensation that could be preventing the burner from igniting?

Lack of Water Pressure: Check with the utility company to make sure no one else is having issues with water pressure. Turn off all of the fixtures and appliances using the water. It is possible you just have too many things trying to draw water from the heater at one time. Make sure there are not any obstructions or clogs causing the problem.

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