HVAC 911 - heating and air conditioning emergency service and residential maintenance and repairs - Boiler Repair
23 Sep

Boiler repair: What to do if water heater pilot light keeps going out

Not having hot water when you need it can be beyond frustrating. The first place to look is the pilot light of your hot water tank. You may find that the pilot light either refuses to light or goes out right away after you relight it. At this point, your goal for a hot shower is practically extinguished.

The problem could be simple, an easy DIY fix-it job. Or it may be complex and require the skills of a HVAC technician. Here is how to troubleshoot the pilot light on a boiler that refuses to light.


Dirty thermocouple

If your pilot light refuses to stay lit or you find yourself re-lighting it often, most likely there is a problem with the thermocouple. This is a device on your boiler that turns off the gas to the pilot if the light goes out. It is a safety measure to prevent the emission of gas, which could start a fire or be a breathing hazard. 

The thermocouple registers heat from the pilot light. If the light goes out, it stops registering heat and closes the valve automatically. This prevents the pilot light from maintaining a flame. 

Too much dirt can prevent the thermocouple from working properly. It can also become bent, or entirely break off.

You could try cleaning the thermocouple with a wire brush or fine grain sandpaper. Be careful not to damage it. If the thermocouple is damaged, call a HVAC technician. Sometimes the thermocouple gets old and wears out. If it no longer functions, it is also recommended you call a HVAC technician to replace it. 

Once the thermocouple is clean, turn the gas back on and attempt to light the pilot light. If it lights quickly without going out, you are back in business! If not, again, call a HVAC technician.


Not enough air flow

A pilot light needs combustible air flow to stay lit. Without air to feed the pilot light oxygen, it can go out. Make sure the boiler is free of clutter, debris or lint that could block air flow. This kind of dirt can also be a fire hazard, so it is best to keep the area around the water heater as clean and clutter-free as possible. 


Faulty seals

Check the seals of your water heater. If the seal no longer forms a complete seal, you should call a HVAC specialist to replace it.


Dirty pilot opening

Occasionally the pilot opening can become dirty and clogged with soot. This will cause the flame to become unstable, wavy and too weak to heat the thermocouple. This needs to be fixed immediately. Shut off the system and try to clean the area with a thin needle. If you cannot clean the area completely, you may need to call an experienced HVAC technician.

Once the pilot opening is clean, turn the gas back on. Ideally, the flame should be blue and cone-shaped. 


Bad gas regulator 

The gas regulator on your gas meter may be faulty. If this is the case, other gas appliances in the house will not work properly. Contact your utility company or a HVAC technician. 


What to do if your pilot light keeps going out

You can try to relight the pilot light flame on your own. Be sure to turn off the gas at the shut off knob, first, then wait a few minutes for the gas to dissipate.

Remove the panel so you can access the burner. Turn the knob to pilot to start the gas flow, pressing and holding the knob down. Light the pilot light with a lighter or use the ignition button. Once the pilot light is ignited, turn the knob to the on position. Check to see that the main burner is turned on.

If the pilot goes out again or goes out frequently, you may have a bigger problem. Try the troubleshooting steps above or call a HVAC technician for a fast solution.


Need help with your boiler? Call HVAC 911!

If trouble shooting these possible causes concerns you, or you just don’t have time, call HVAC 911. We are a network of qualified HVAC technicians. Your call will be quickly connected to a licensed and bonded contractor in your area fast!

All our HVAC technicians are highly skilled and trained. They have undergone rigorous training and a qualification process, including background checks and drug testing. 

Don’t settle for cold showers, get your water heater back up and running pronto! That hot shower is only a phone call away.