Is your pilot light going out?

A pilot light is a small device that emits a blue flame in which is also part of an old model furnace or water heater. It provides the flame that is needed to start and maintain the fire that is produced in the boiler. The problem is, if the pilot is faulty or goes out from time to time, the boiler won’t ignite and the gas would keep on coming out of the gas tube which poses a danger. It could accumulate and possibly explode inside the house. This is when we realise the situation needs to be addressed with some urgency.

Cause: The pilot is dirty

The pilot might be already covered in dust and soot. It is an accumulation of carbon deposits that collect inside the tube and the thermocouple which incidentally is a safety device that regulates the supply of gas to the furnace.


1. First, turn off the gas and remove the pilot light tube and thermocouple from the furnace.

2. Set them on a piece of cloth and use a rag or wire brush with soapy water to clean both items. You may also use a needle to poke the “orifice” of the pilot to remove anything that might be blocking it.

3. Reassemble both the pilot and thermocouple back to the furnace.

4. The resulting flame must be blue with a white center on it.

Cause: Gas valve problem

Possibly, the valve may be worn out or water damaged. If it is electronic then the problem could also be an ignition component or some glitch in the safety circuit which is the reason the boiler won’t fire.


1. It would be a good idea to contact a certified contractor who is an expert on the type of boiler that you currently have.

Cause: Expired or a bent thermocouple

An old thermocouple might be malfunctioning for the reason that it may already be worn out. Or, might just be bent away from the flame which results in the boiler not turning on.


1. Wait for the thermocouple to cool down and bend it back to where it can reach the flame. 2. Replace the thermocouple.

Cause: Seals are faulty or not working properly

Seals should be able to form a complete cover to any crack or edge that needs to be addressed. If not, then it could be the problem.


1. Replace the seals.

Cause: Bad gas regulator

A regulator that may have gone bad which is usually located outside of your house could be the culprit. Your furnace might not be getting enough gas which could be the reason for the boiler not working.


1. Contact your local heating repair company to address the problem. Avoid DIY on gas pipe issues.

At Grand Union Plumbing & Heating, we like to keep our clients happy with our great service and skilled workmanship. When it comes to taking care of your boilers, we are first-rate in servicing, installation, and repair of all types of boilers and heating systems. Our heating engineers are more than ready to serve you on a year- round, any day call out, even on a short notice.

Call us.
We are available in the Milton Keynes area at a fixed call out fee.