2 Reasons Your Boiler Pilot Light Will Not Stay Lit

Posted on: 16 April 2015

While many newer boilers do not have pilot lights, older ones do. If your boiler has a pilot light, this light must be lit in order for the boiler to work and produce heat. If your boiler isn't working because the pilot light is out, you can try relighting it, but there's a chance that it will not stay lit. This is a common problem with older boilers, and here are two things that can cause this to happen.

Dirt around the light

A pilot light needs a clear path for the flame, and this can get blocked from normal dirt and dust buildup. This is normally the first thing an HVAC company will check when they begin troubleshooting, and this is often what is causing the pilot light to keep shutting off.

The simple fix for this is to clean the light. A heating repairman will often do this by using cotton balls to remove the dirt and soot from the light. Once it is cleaned out, the light will usually stay on and work properly.

If the pilot light is really dirty or really old, the plumber may suggest replacing it with a new one. Once you get a new light assembly, it should work perfectly for a long time.

Bad Thermocouple

If the pilot light is not dirty, or if cleaning the light didn't fix the problem, checking the thermocouple is the next step. A thermocouple is a very inexpensive part, but it serves a key purpose. It is often viewed as a safety switch, because it controls the gas valve on the furnace. If it senses a problem with the pilot light, it will stop the gas valve from opening.

In addition to this, a worn-out thermocouple will cause the pilot light to go out simply because it detects a problem. Even though there really isn't a problem with the gas or pilot light, a bad thermocouple will send the message that there is a problem.

This is usually a simple fix for most plumbers, and it is usually relatively inexpensive. Replacing this part will require removing the old one and installing a new one, and this is usually a quick job to complete.

If you are good at fixing things yourself, you may want to try these two options. If the pilot light still will not stay lit, you should call a plumber or HVAC company like Lowry Services: Electric, Plumbing, Heating & Cooling to come to your home to inspect your boiler system.