7 reasons why your boiler won’t fire up

It’s the coldest time of the year, and the last thing you need when you wake up in the morning is a tank full of cold water and no heating. If your boiler isn’t working, it can ruin your whole day, or even pose a potential health risk if there are young children or vulnerable adults in a cold house. You need to get things back on track, and quickly.

It’s important to find out straight away why your boiler won’t fire up, and respond accordingly. Let’s have a look at what the problem could be, and what to do to resolve it quickly.

Can you see the pilot light?

If your pilot light has gone out then your boiler will not fire up properly. Check your user manual and you should have a start-up procedure you can use to get the pilot light going. Once it’s lit, the boiler should kick in. If you have an old boiler with a pilot light that keeps going out then it may be worth calling in an engineer to check if the boiler is operating properly (and safely), or whether it needs replacing.

Is the pressure okay?

Your boiler relies on a certain amount of pressure to operate correctly, and that’s usually indicated on the pressure gauge. If you have a reading of 1 bar or less then there may not be enough pressure in the system to initiate the boiler. If you have a combi boiler then you can increase the pressure via the filling loop, which is a flexible metal pipe with a valve at either end. This is usually located underneath the boiler, so it should be easily accessible.

Look for the valve that has a slot for a flat-head screwdriver, and gradually start to turn it. You should hear the sound of water flowing, which is used to increase the pressure. Keep an eye on your pressure gauge until it reaches around 1.2 bar. This is the correct level for cold water, and the pressure should increase to between 1.5 and 1.7 bar when the water is hot. If you have to do this regularly then the boiler may have a leak and should be checked by an engineer.

Have you reset it?

Sometimes, resetting a boiler can stop it from working properly. If you have had a power cut or the boiler has been reset you may need to reprogramme it with the correct on-off times, so that it comes on when you want it to. Check your user manual for the correct procedure, but in most cases it will be simply a matter of resetting the timer using the buttons on the front of the panel.

Is there a smell?

If you notice any unusual smells coming from your boiler then call out an emergency gas repair team straight away. Do not attempt to relight the pilot light if it has gone out, until the boiler has been checked to make sure it is safe to do so.

Turn your room thermostat up briefly

If you set your room thermostat to below 21 degrees then it may prevent the boiler from firing up, as its programme will think that there is no need for the boiler to come on. Switch the thermostat up briefly to 22 degrees and see if the boiler fires up. If it doesn’t then you may have to look for other causes.



Are you on a pre-paid meter?

If you don’t have enough credit in a pre-paid meter then your boiler will not fire up. Make sure you have enough credit, and if necessary, top it up.

Has your main fuse box tripped?

Sometimes, it can be a simple matter of turning a trip switch back on. If you’ve checked everything else then don’t forget to take a quick look at your fuse box and make sure your boiler switch hasn’t tripped.

Calling in the professionals

If everything else has failed and you still can’t get your boiler fired up, it’s time to call in the experts. Call-out fees can be expensive, so make sure you’ve checked all the basics first. Suppliers like British Gas offer fixed prices for boiler repair and ongoing cover as well as one off repairs. So, whether you have a contract or not you can contact British Gas to find out more about booking a repair.

Always make sure the engineer you choose to call out is Gas Safe qualified and registered, as they are the only people legally allowed to repair a faulty boiler.

Call British Gas on 0871 244 9817

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