Why Does My Boiler Keep Turning Off by Itself?

September 12, 2022
Model house wrapped up in a scarf on a radiator.

If your boiler has been turning itself on and off for no apparent reason and you can’t seem to work out why, you have come to the right place. There could be a number of reasons why your boiler is turning itself off and in this article we’re going to look at some of the most common.

Combi Boiler Turning Itself On and Off

If you have a Combi boiler and it’s started turning itself on and off, this could be due to the boilers 'preheat’ function. Combi boilers only heat the hot water you use. So, it is perfectly normal for your Combi boiler to turn itself on and off in order to pre-heat water for when you need it.

However, if your Combi boiler is turning itself on and off every few minutes, this could indicate a problem called ‘short-cycling’. This term refers to the frequency your boiler is turning on and off. If your boiler is short-cycling anywhere from a few seconds to a few minutes, there could be a problem and you will likely notice a spike in your energy bills.

If your Combi boiler is showing signs of short-cycling, you should call us to book a repair.

Problems with the Boiler Valve

Your boiler's valve helps regulate the water temperature in your system. If there is a problem with the valve, it means the water temperature is no longer regulated. This can result in water that is heated too hot which in turn causes your boiler to turn itself off to avoid overheating.

If your boiler has a valve issue, you are more likely to experience leaks within the system. This is because the water will be reaching temperatures that your boiler cannot safely support. If you suspect your boiler has a valve problem, you need to call our specialist engineers to come out and fix the issue.

Fluctuating Water Pressure

Your boiler should have a nice steady water pressure to maintain a comfortable temperature in your home. Fluctuating water pressure can be a problem, whether too much or too little, and can cause your boiler to turn itself off in order to avoid damage.

When your boiler switches itself off it will display an error code. It’s unlikely the error code will mean anything to you, unless you know a thing or two about boilers. So, if your boiler is displaying an error code it’s a good idea to give us a call.

Boiler Leaks

When your boiler has low pressure, this can be the result of a leak in the system. You might spot leaks coming from a pipe joint, from underneath your boiler system, or from a radiator. Spotting leaks early lets you take action and prevent more costly problems in the future.

If your boiler is leaking, it won’t be long until it turns itself off. The only way to get your boiler up and running again is to fix the leak and repressurise the boiler. Our specialist boiler engineers can sort this for you without any problems.

Issues with the Thermostat

Another common reason why your boiler might be turning itself on and off regularly is due to issues with the thermostat. The thermostat monitors the external temperature around your boiler. If the temperature drops below the level you’ve set on the thermostat, your boiler will turn on by itself.

If, however, your thermostat is faulty then it cannot accurately record the external temperature and so will turn on and off when you least expect it. If your boiler is behaving erratically in this way, a faulty thermostat could be to blame. Upgrading to a smart or wireless thermostat should fix the issue and help you save money on your energy bills.

Malfunctioning Water Pump

Your boiler's water pump helps move hot water around your central heating system. This water travels from your boiler through your home, feeding your pipes, radiators and (if you have one) your hot water cylinder, before returning back to the boiler. When the water pump works effectively, the cycle of water is constant and maintained at your chosen temperature.

However, when your water pump starts malfunctioning, this means it’s no longer pumping water around your home as it should be. As a result, your boiler may turn itself off to protect the system from overheating. Issues with the water pump can cause numerous problems, from overheating to leaks. You will need to call our boiler engineers to fix the problem for you.

Air Trapped in the System

Another cause of boilers turning themselves on and off again is due to trapped air in the system. Sometimes, air can gather in your pipework or radiators. This problem is easy to spot because your pipes and radiators will make noise as water circulates through them.

If you suspect there is air trapped in your system, you can try bleeding your radiators using a radiator key. This should release any excess air and allow your boiler to work more efficiently. If bleeding your radiators doesn’t make a difference, you will need to call in our specialists.

Frozen Pipes

If you didn’t already know, the pipes in your home can freeze over the winter months when temperatures drop too low. This happens due to extreme weather or lack of appropriate heating.

One of the main risks to your boiler of frozen pipes is a frozen condensate pipe. This pipe is what carries the waste or acidic water away from your boiler to the drain. If this pipe freezes after being exposed to very cold temperatures, the waste water from your boiler has nowhere to go, creating a blockage that backs up your boiler.

A blocked condensate pipe may result in gurgling sounds in your boiler or fault lights on the system. To protect itself from further damage, your boiler will switch itself off. To fix this problem, the best thing to do is to unfreeze your pipes using warm water and then reset your boiler.

Call Our Boiler Engineers

We know how frustrating it can be when your boiler turns itself on and off. However, we hope this article has helped outline some of the possible causes. Often, your boiler is turning off to protect itself from damage caused by an underlying issue. If you notice this is happening, it’s important to take action.

If your boiler is exhibiting signs there’s a problem, call our team of specialist engineers today. With over 12 years’ experience we can rectify any boiler issues and get your system up and running again.

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