The 5 most common part(s) or condition(s) which contribute to the symptom Water Heater Does Not Light are listed below. Check or test each item and watch any available videos. If you are still unable to solve the problem you may need to do additional research and troubleshooting. Remember, with our 365 Days. Period.® return policy you can return any part for any reason. So, go ahead and buy it to try it. No other parts retailer offers this unconditional return policy.
For the symptom you selected, these are the most common parts or causes, ordered by the likelihood of fixing the symptom.
If the water heater burner does not light the igniter might be bad. Some water heaters use a hot surface glow bar igniter at the gas burner for ignition. If the igniter fails and does not glow with voltage applied it is bad and should be replaced.
If the water heater burner does not light the pressure switch (sometimes referred to as the vacuum switch) might be bad. The draft inducer motor air flow through the burner should close the pressure switch to signal the control that proper air flow is present and the ignition process can continue. If the water heater does not heat the pressure switch might be defective causing the ignition process to stall.
If the water heater burner does not light than the thermocouple may have failed and will need to be replaced. On gas water heaters that use a standing pilot a thermocouple style flame sensor might be used to detect the pilot flame. The other end of the thermocouple attaches to a gas valve and thermostat assembly. Usually when a thermocouple fails the pilot can be lit but drops out as soon as the button on the gas valve is released.
If the water heater burner does not light than the pilot may have become restricted. If the pilot can not be lit then the pilot is likely plugged with carbon deposits. Sometimes the pilots can be removed and flushed with HOT water to clear but usually a restriction requires replacement of the assembly.
If the water heater burner does not light the spark igniter might be bad for the pilot flame. Some water heaters use a spark electrode to light the pilot flame. The control module sends intermittent high voltage sparks to light the pilot. No spark at the pilot could indicate a defective spark electrode.