Why is my gas boiler not working?

2.Leaking and Dripping

Gas Boiler / Problems The most common cause is a broken internal component, such as a pump seal or pressure valve. If the leak is coming from the pressure valve it may be a case that your boiler pressure is too high. If it’s coming from the pump seal, it may have become worn out and need replacing.

3. Kettling - Gas Boiler Problem

Gas Boiler / Problems Kettling is more common in areas with hard water, but can also affect boilers in soft water areas. Not only does it cause your boiler to work harder and thus cost more to run, it can also shorten the system’s life. If your boiler is kettling, it’s advisable to call out a gas safe registered engineer who will likely flush out your system to remove the build-up of these deposits and ensure the system is working properly once more.

4. Pilot Light Goes Out

Gas Boiler / Problems The pilot light is a small blue flame that’s kept alight to light a larger burner. If it keeps going out then it could be caused by a broken thermocouple stopping the gas supply, a draught blowing the pilot light out or a deposit built up in the pilot light.

Before trying to reignite the pilot light, it’s very important to check that there aren’t any issues with the gas supply. If your gas stopcock is on but your boiler isn’t receiving any gas, or if none of your other gas appliances are working, then you should contact your gas supplier. You can then try relighting the pilot light yourself – ensuring you follow the instructions found in your boiler’s manual for igniting the pilot light.

5. Low Boiler Pressure

Gas Boiler / Problems Checking the pressure of your boiler couldn’t be simpler, just take a look at the built-in pressure gauge. If you find that the needle is below 1, then there might be an issue with low boiler pressure and your central heating system won’t function properly.

There a number of reasons why this may be happening:

• A water leak in the system
• The pressure relief valve needs replacing
• Recently bled radiators

6. Frozen Condensate Pipe

Gas Boiler / Problems All condensing boilers, whether Combi, System or Regular, have a condensate pipe which transports acidic water, caused by waste gas, away from the boiler. In most cases, this pipe will run outside into a drain and because of its location it faces the risk of freezing during the winter months.

If the condensate pipe has frozen then your boiler will probably display a fault code or warning notification. To locate the condensate pipe, it’s the plastic pipe (usually white and roughly 2cm wide) and should lead outside of your property into a drain.

You can thaw a frozen condensate pipe using a hot water bottle, microwaveable heating pack or warm cloth on the frozen part of the pipe. Alternatively hot, rather than boiling, water can be poured over it. After thawing the pipe, you might need to reset the boiler to fire it up again.

7. Thermostat Issues

Gas Boiler / Problems If the thermostat is losing accuracy or turning the heating on/off when it’s not supposed to it might be time to invest in a new one. It’s worth making a couple of common sense checks first though, as sometimes these can be easily overlooked. Check your thermostat to ensure it’s in the on position and that it is set to the correct settings i.e time and schedule – it’s always possible that it could have been knocked.

One other consideration to make is that your home might be warmer than you think and a thermostat won’t allow the boiler to heat your home higher than the temperature it has been set at. If this is the case then try increasing it in very small increments until you find the temperature that’s right for you.

If none of the above apply it’s possible that your thermostat may have malfunctioned or lost accuracy over time, in which case it is probably time to consider a replacement.

8. Strange Banging, Whistling or Gurgling Noises

Gas Boiler / Problems Air in the system is a common cause, alternatively it could be that the water pressure is too low or it’s kettling. Imminent pump failure, particularly in older systems, could also be responsible for strange banging noises.

You might be able to determine the type of problem your boiler is having based on the type of noise it is making. For example a noise similar to that of a boiling kettle is usually a result of Kettling. Our guide to central heating noises can help you determine the cause of your noisy boiler.

9. Radiators Not Heating Up

Gas Boiler / Problems In the case that some of your radiators aren’t heating up then there could be a build up of sludge or air in the system. If only the bottom of your radiator is getting hot then you might need to bleed the radiator. This is fairly straightforward and doesn’t require an engineer but if you don’t feel comfortable doing it then contact a professional.

If certain radiators aren’t getting hot then your radiators could need balancing, which can also be done without the help of an engineer but only if you feel confident doing it. The process involves adjusting the valves on all of the radiators in your property, to ensure each is getting enough hot water to work effectively. Our guide to balancing radiators can take you through the process.

Should you try bleeding and balancing your radiators but have no luck then you could well have an issue with sludge build up preventing a free flow of hot water to the radiators. A professional engineer can remove this build up by chemically cleaning or flushing the system, this is something that you shouldn’t try yourself.

10. Boiler Keeps Switching Itself Off

Gas Boiler / Problems Could be low water pressure, a problem with the thermostat or a lack of water flow due to a closed valve, air or the pump not circulating the water in the system properly. We’ve covered each of these issues in more detail above, but if you still can’t identify the cause we recommend calling out a Gas Safe registered engineer to take a look at your boiler.

🚕 Midland, TX?

From Glendale, AZ?