Does the Pilot Light on the Gas Boiler Affect the Gas?

Ignition System Basics

• Gas alone can’t produce a flame to heat water in a gas boiler. For a gas boiler to generate hot water or steam to heat a home, it must have a functional pilot light and operational gas valve. These two components work together to energize burners that heat water in the boiler’s water tank. It’s the extreme heat of a pilot light that generates a flame when gas is released from the valve. The pilot light’s flame is positioned directly underneath burners that heat the water.

Circuit Breaker or Fuse

• The pilot light is powered by electricity, which is regulated by a circuit or fuse, depending on your home’s electrical configuration. If the circuit breaker or fuse for the gas boiler trips or blows, the pilot won’t light and may go out if it’s a standing pilot that’s always on. As a result, you may smell a natural gas odor near the boiler because the flame that would otherwise be produced by the pilot light isn’t ignited to burn gas. Locate your home’s circuit breaker panel or fuse box and either reset the breaker to the “On” position or replace the gas boiler’s fuse.

Pilot Light

• A draft near the gas boiler can cause a pilot light to extinguish. When this happens, the pilot light must be reset. Otherwise, the gas valve continues to release gas even though the pilot light is out. Instructions for how to reset a pilot light are usually on the boiler’s front panel or on the inside door. Depending on your boiler type and age, there may be a red reset button to press or you may need to ignite the pilot with a lighter to reset it. Yet before you reset the pilot light, you must turn the gas valve off and wait a few minutes for the residual gas to dispel. If you don’t turn off the gas valve prior to resetting the pilot light, all of the residual gas in the boiler can also ignite and produce a temporary flareup.

Considerations

• There are certain gas boilers that have pilot lights with standing pilots. A standing pilot always stays lit, regardless of whether or not the gas valve is open. For example, when you raise the thermostat in your home to make the house hotter, the boiler will direct the gas valve to release more gas so that the pilot light’s flame gets larger. If you lower the thermostat, the gas valve will close and the pilot light’s flame will diminish in size, but not go out. The amount of gas released from the valve affects the size of the pilot light flame, but a burning pilot light won’t affect how much gas is released from the valve.