Home Improvement

Boiler Not Working – Common Issues and Fixes

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It’s always a dreadful feeling to go into the bathroom for a nice hot shower and to discover that your boiler is not working. Some advanced models have LCD screens, which show exactly what the problem is. Sadly, the majority of units don’t have such advantages. So, if you:

  • Have restarted the unit, but is still refuses to work;
  • Have switchen on the heating, so the boiler would switch on too, but it doesn’t;
  • Moved to a new house and the boiler is not working.

Read along to see the most common reasons why your boiler is not working and how to possibly fix them.

Table of Contents:

Power supply

The first, most obvious, and for that reason, overlooked reason. Different factors can contribute to your boiler not having power:

  • Power outage
  • Mains power source for boiler has accidentally been switched off
  • Roadworks resulting in electricity being cut for several hours
  • A bigger problem with your home’s entire power supply
  • Tripped switch on your fuse box due to power cuts

How to fix it?

For starters, switch off and on your boiler. Sometimes a system restart is all a machine needs. If that doesn’t help, check your fuse box next. Perhaps the switch for your boiler was tripped by a power outage. Finally check the mains power source for your boiler.

Gas supply

A lot of boilers in the UK are connected to the mains gas supply. If there is a problem with that said gas supply, then your boiler won’t work.

How to fix it?

Generally it is advised that a qualified gas engineer takes care of this job, but there is something that you can do, to at least, check:

  • Check whether your gas appliances are working. For example your gas hob. Turn it on for a few seconds and see how quickly the flame dies down. If it does quickly, your gas supply is probably switched off.
  • Check your gas bill. Maybe you forgot to pay this month and that’s why the service has been cut.
  • If you have a payment meter, check to see whether you have enough credits.
  • Check your gas provider’s website to see if there’s a problem with the entire system.

Water pressure

The pressure fluctuates from time to time and that’s normal. However, if it gets too low or too high, then both instances will result in the boiler not working properly. Usually , high pressure can trip the system. Fortunately this issue is easy to fix by a non-trained person.

How to fix it?

Check the pressure gauge. It will be either a digital setting on a display or a clock-like feature. If the pressure is too low (one bar or below) you will have to top it up. Every unit is different, so you’d have to check your user manual. The same principle goes if the pressure is too high.

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To learn more about our handyman services, check our website.

Frozen condensation pipe

Sometimes when the winter is extremely cold, unprotected or badly installed condenser pipes can freeze. These pipes connect your boiler to the nearest outside wall. As their name suggests, they move away condensation from your boiler. Because this pipe is connected to the outside wall, it’s really easy for the excess water inside to freeze, resulting in your boiler not working.

How to fix it?

Fortunately this problem is quite easy to solve. Warm up some water (not boiling water) and pour it over the exposed end of the condensation pipe. The warm water will melt any frost or ice. Afterwards just reboot the boiler and it should be back to normal.

Pilot light gone out

The pilot light is a small internal flame which lights the gas released from a burner. Small amounts of gas are constantly released and so the flame burns permanently. The pilot light can go out every once in a while, usually because of a strong draft or debris blocking the jet. Once the system detects there is no light, it will stop releasing gas, for your safety. The pilot light has to be relit back, in order for the boiler to work. This method is different with different boiler models.

How to fix it?

Older boilers have a switch or button for reigniting the pilot light. If you’re not sure where it is, check online for a pdf version of your boiler’s manual.

For newer boiler models, a restart and reset will usually suffice. 


If the thermostat is set to a temperature which is too low, the boiler won’t start. Your heating system will not switch on until the temperature of your home goes below that of the current setting.

How to fix it?

This problem is quite easy to fix, just set your thermostat to 20 degrees or more. Your heating should start working once again and your boiler will switch on.

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System crash

New generations of boilers have tiny computers inside them. While they’re not too complicated, just like any computer, they sometimes may crash. To be fair though, that happens rarely if at all. Still, a system reset every now and then.

How to fix it?

Press the restart button or simply turn on and off the boiler. If all else fails, maybe a simple restart would do the trick.

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Call in the professionals

If you’re still not sure what the problem with your boiler is, we suggest calling in some professional help. Fantastic Services works with experienced and fully equipped plumbers. Our boiler repair services cover all boiler brands and you can take advantage of priority booking and case handling if you’re a part of our Fantastic Club.

Boilers are serious business and if you’re not sure what you’re doing, better leave it to someone who does. For your extra peace of mind, you can consider investing in a boiler and central heating cover plan and entrust your repair needs to true professionals.


  • Check if there’s power to your boiler
  • Check if there’s gas to your boiler
  • Check the water pressure
  • Check if pilot light has gone off
  • Check the temperature setting on your boiler thermostat


Have you run into problems with your boiler recently? How did you manage to fix them? We’d certainly like to know in the comment section

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