Tankless water heaters work well and typically save you money, but they aren't maintenance-free. Know the common issues that can affect a gas tankless water heater so you can recognize problems as they occur.

1. Dirty Burners

A tankless heater has a burner that sits below the water lines. The burner ignites when hot water is necessary, then it heats the water as it flows through the supply lines and to your tap. If the burner becomes dirty, it will either fail to ignite or it will transfer heat poorly, resulting in cold or lukewarm water. A service tech can disassemble the burner and clean it thoroughly so that the heater works properly again.

2. Failed Igniter

The gas burner depends upon the igniter, which is what lights the gas so that combustion and heat occurs. If the igniter malfunctions, you will end up with gas but no combustion. You will not get any hot water and you may even pick up on a faint gas odor unless your heater has a safety that closes the gas valve when there is no combustion present. You will need to have the igniter replaced in order to get hot water again.

3. Clogged Valves

Clogged valve tips can prevent gas from entering the burner, which will also result in cold water since there is no way for it to be heated without gas. Valves can become clogged from dust or dirt, so it is important to have the water heater tuned up and cleaned out annually. Fortunately, clogged valves can be cleaned, after which your water heater should work perfectly again. In some cases, damage to the valves may be the cause of the clog. In this case, the valve tips will need to be replaced.

4. Poor Ventilation

A gas water heater must be ventilated, otherwise dangerous fumes can collect inside your home. Poor ventilation can also cause the water heater to overheat, which will then lead to it over heating and shutting down. Every gas water heater should be vented to the outdoors. A service tech can check that the current ventilation is sufficient or add more if needed.

5. Corrosion

Corrosion can happen in any water heater. In all tankless heaters, it typically affects the supply lines. There is another part also at risk in a gas heater — the burner pan. Sometimes leaks develop in the lines over the pan, causing water to drip onto the pan and cause corrosion. The corrosion can inhibit heating.

Contact a tankless water heater repair service for more help with your gas heater.