10 of the most common reasons for a boiler to break down

On a day to day basis, few of us ever thing about our gas boilers. We get hot water from the tap and hot water pumping through our radiators and as long as that happens, we can get on with more important things.

But when your boiler does breakdown, what caused it and what can be done to prevent it from happening again?. At WrightGad, we are a Which Trusted Trader, an approvied Baxi Installer and are of course Gas Safe Registered. So we know a thing of two about boilers and here is our top ten list or reasons why a boiler can break down.


1 - My boiler is not producing hot water or heat

From broken diaphragms and airlocks to the value failures and even a shut down because of a loss of pressure. Your boiler not producing hot water is the most obvious sign that it is broken but there are more than just one or two reasons why this can happen. As a qualified local gas engineer, we can inspect your boiler and identify the issue and replace any parts that have developed a fault.

2 - My boiler is leaking water

Broken pump seals and faulty pressure valves are likely reasons that your boiler has developed a fault. But because so many of us have our boilers hidden away in a cupboard or a storage room, you may not notice that your boiler has a leak until it shits down. There are a few subtle things that can help you spot it though. If you notice condensation on the inside of your window in the room that the boiler is located in, it could have been generated because of a damp puddle caused by the leak. Likewise, if you have noticed a damp smell in the room, simply inspect the boiler for any signs of a little leak or drip.

3 - My boilers pilot light has gone out

It could be a strong draught or more likely a build up of residue on the pilot light that has caused it to go out. It may also be that a thermocouple has stopped the gas supply. If your boiler is properly serviced every year then any residue build up would normally be cleaned away. So if your boilers pilot light has gone our and oyu had your boiler serviced recently, it may not be this that has caused it.

4 - My boiler is making a strange noise

If your boiler has been making a strange banging, gurgling or evena kettle like whistling noise, don't panic too much. It may not be serious. It may just be air trapped in the system. Whether that has been caused by a leak in the system or something else is what we can help with. And if you have an older gas boiler, it may be an early indication that your boilers pump is about to fail.

5 - My boiler has lost pressure

If your boilers pressure guage is showing a reading below 1 then you have a pressure issue. There are a few potential reasons for this. From a water leak to a faulty pressure release valve. And if you have recently bled your radiators, then it is highly likely that there was enough air in the system that by bleeding the radiators, you caused the pressure to drop and for the boiler to shut down.

6 - My boiler keeps switching off or on

Your boiler is governed by the thermostat. It is responsible for switching your boiler on and off. So if the boiler comes on normally but shuts off after a period and your home is still cold, it could be that the thermostat is faulty and simply thinks it has reached its shut down temperature.

7 - My radiators are not getting hot

Try this simple test. Put the palm of your hand (carefully of course) onto the lower part of the radiator. And then to the top. Is the bottom hot and the top cold? If this is the case then there is air in your radiators and they need to be bled. If the bottom of your radiator is cold and the top is hot, then there is a build up of iron oxide sludge in your heating system and we need to remove it before it causes more damage to your boiler heating system.

8 - My boiler has turned itself off and won't come back on

If your boiler is flashing a letter or number on its screen, this is a fault code and it is telling you what is wrong with it. If you check your boilers manual, you will be able to see what the fault log states is the problem. But if your boiler has automatically shut itself off, it is commonly because of a thermostat issue, low water pressure, a low water flow because of a closed valve or an issue with the pump which is causing poor water circulation.

9 - My boiler sounds like a kettle boiling

We are not joking. Boilers can sound like a kettle is boiling. While this is more common down South, it is generally caused by lime scale or sludge build up on the heat exchanger. This restricts the flow of water and causes the water to boiler quickly which in turn causes the kettle boiling sound.

10 - My boiler condensate pipe has frozen

Did you know that your boiler has a condensate pipe? It is the pipe that transports acidic water (a result of waste gas) away from the boiler to an outside drain. As we all know, the weather in Renfrewshire can get cold quickly so when the Winter Wind hits the West Coast of Scotland, it can freeze this pipe and prevent it from drainaing. If this happens, the boiler will go into shut down mode and flash a fault coe on its screen.


And there you have it. Ten common reasons why boilers break down. If you like in Renfrewshire and the West Coast of Scotland and have suffered from a broken down boiler and want it fixed by a trained professional then call WrightGas today. Gas Repairs, done the Wright way!