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Boiler not working? Here's (probably) why and how to fix it

If your boiler's not working and it's given up the ghost, it could be something so basic you seem silly. Or, something so severe, you could be left with a silly bill. Let's hope it's not the latter.

If your boiler is broken.

So is your will.

So are your dreams.

So is your home.

As such. You’ll want the cheapest fix, or the cheapest new boiler. Or do you?

So, here are (some surprisingly) common issues – which are free and easy to fix. Closely followed up by more sinister and costly reasons why your boiler isn’t working.

Common broken boiler issues (with free and easy fixes)

Fix a Broken Boiler (For Free)

#1 - Check the boiler is switched on

Turn Boiler OnAn absurd and seemingly patronising statement at first, but, boiler installation companies up and down the UK are relentlessly earning call out fees for customers who haven’t realised their boiler has been switched off – sometimes at the mains.

It can be human error, or perhaps you switch off appliances whilst sleepwalking but one of the most common causes are power cuts.

Your boiler probably hasn't broken, so switch the bugger on.

Cost: Free

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#2 - Have you paid your gas bill, or does the gas meter have credit?

Broken Boiler Pay Your Bill

Another silly reason at first glance but understandably common. People take boilers for granted and aren’t always acutely aware of the corresponding gas bill.

If you don't pay your energy bills, your boiler won't work. Simple.

Perhaps you upgraded to Netflix HD last month sending you tumbling beyond your overdraft. Or, it’s just the energy companies fault. The scumbags.

Either way – do check.

#3 - Boiler not working? Check for low pressure

Top Up Boiler Pressure

Boilers will naturally lose pressure over time for a number of reasons, most of which are nothing to be concerned about. If your boiler's not working, and it's simply low on pressure, you'll be back up and running in no time.

Read how to breath new life into a broken boiler that's losing pressure.

It’s super easy – one check and one tap turn. 

How to check if your boiler's not working because of pressure issues
Glance at your boilers pressure gauge – the clock-like feature staring at you like a cyclops from the front of your boiler. When the boilers off, its arrow should point to the green zone – around 1 BAR.

Your boiler pressure being too high is also a thing.

How to fix your boiler's pressure issues
We recently published an article about boilers losing pressure - it'll tell you how to fix it.

#4 - Boilers pilot light may have gone out / not catching

To ignite the gas and deliver heat and hot water, the boilers pilot light (basically a tiny internal flame) will need to be alight when your boiler is active, in order to burn the gas.

Sometimes this flame will go out, whether caused by sudden drafts or wandering spirits trying to make contact.

Broken Boiler Pilot Light

In older boilers, you’ll be able to check this by peering through the casing to visually check on the boiler flame. If it’s out, you should try restarting/resetting your boiler. If the boiler is still not working, you'll need to call (and pay) a heating engineer (sorry).

#5 - Check your condensate pipe (winter conditions only)

Boiler Broken Frozen Condensate

Your condensate pipe travels from your boiler, to (usually) the nearest outside wall and is where excess liquid caused by condensation from your boiler is deposited outside.

This small amount of slow dripping water is naturally vulnerable to freezing in cold weather. 

A frozen condensate pipe will lead to a blockage, meaning the excess water has no escape route and your boiler will shut down upon detecting this. It's a surprisingly common cause of a boiler that's not working.

How to fix a frozen boiler that's not working
Gently pour warm water over the frozen condensate pipe until the frozen water has melted away.

After you’ve tackled that – reboot your boiler.

How to (try to) prevent
Checking regularly on the pipe as though it’s an orphaned chick you rescued from a fallen nest is one avenue.

But, wrapping the external part of the pipe in foam or cloth to prevent future freezing is recommended.

#6 - Check your boiler's thermostat

Faulty Thermostat

Like Governments blaming immigrants and the poor for their shortcomings, boilers are often held accountable for the failings of their controllers.

If you’re privileged enough not to have to physically approach your boiler to switch it on, you should check if it’s actually your timer that’s not working. Your boiler might be working just great.

How to check is your boiler's not working because of a faulty thermostat:

  • Check it’s switched on with a full charge or working batteries
  • Ensure that the temperate is turned up to the level you require
  • Check you Wi-Fi connection if applicable with the boiler thermostat
  • Run over the time settings, making sure no ‘vacation modes’, stand-by options or unnoticed daily schedules have been set.

How to fix

  • Replace the batteries in your thermostat
  • Clear any settings and restore to manual operation
  • If all else fails, refer to the thermostat manual

Common issues for a boiler that's not working (requiring an engineer and £££)

Fix a Broken Boiler (Costly)

#1 - Pressure issues (due to faulty parts)

Boilers thrive on pressure and require a balance of it so delicate, that butterflies start to look like drunken Geordies. 

A loss of pressure will result in an inadequate amount of water running through your boiler that will in turn struggle to provide heat to your home – or enough hot water, obviously.

Too much pressure and your boiler won’t have time to thoroughly heat the water – amongst other issues, like putting internal parts under pressure and causing leaks.

Culpable boiler parts include; expansion vessel, pressure release valve and the heat exchanger. These are all too often heartbreakingly expensive repairs that are much more likely to lead you down the new boiler route.

How to check if your boilers not working because of a leak
Refer back to the trusty pressure gauge on your boiler; it shouldn’t be under or above the green zone whilst the boiler is switched off and never in dreaded red zone.

If it is, switch the boiler off.

How to fix a leaking boiler that's not working
A qualified Gas Safe heating engineer will need to strip the boiler down and inspect all possible parts – replacing them where possible.

Boiler over 10-years old with a faulty part? Gently massage the idea of a new boiler into your thoughts. You’ll thank yourself later.

Boiler not working and the repair going to cost you an arm and a leg? Save your last two limbs and upgrade to a hot new boiler with a 10-year warranty and mind bogglingly low monthly payments.

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#2 - Leak in the boiler, or heating system

Boiler Not Working (Leak)

Leaks within the boilers internal parts or around the heating system (pipework) aren’t just bad for your carpets and floorboards.

They’ll cause a loss in pressure that we’ve already established is a boiler killer.

How to check
Look for patches of water and drips directly underneath your boiler (within the case if you can) and also check the pipework throughout your house, particularly around the joints/bends in in the pipes.

How to fix
You’ll need a boiler engineer to give your system a once over and either replace any faulty parts or secure any leaks in pipework that can be repaired.

If it’s an internal boiler part that’s failed, you may well be better off upgrading to a new boiler rather than falling into the trap of eternal repairs.

Boiler not working during the financial low of your life? Typical. Get a new boiler now – pay one YEAR later.

#3 - Boiler simply won’t turn on (no power at all)

If your boilers not working to the point where it appears utterly dead with no sign of life. It’s likely an electrical issue.

Most commonly this will be a busted PCB (circuit board) and could set you back a few hundred pounds.

How to check
The age old off and on again at the mains power is your only real play here. You’re going to need an engineer to diagnose the issue.

If your boilers not working at the same time as your TV, kettle, lights and washing machine – get calling your electrical provider.

How to fix
If your PCB board has gone into the long night then it’s going to need a costly replacement.

Hopefully though, you’ll get away with a faulty fuse or other less expensive repair.

Is your boiler working but not providing hot water?

No Hot Water From BoilerA boiler not working that still provides heating is a brave boiler indeed.

But it definitely has a faulty part, and it’s probably the diverter valve.

The aptly named diverter valve, diverts water to either your radiators, hot water outlets or both – depending on what you’re demanding from it.

How to fix
Your diverter valve is going to need replacing, or you’re going to need a new boiler.

Is your boiler working but your radiators aren’t getting hot?

Boiler Working Not Radiators

This is unlikely to be your boiler not working.

Over time, heating systems – pipes and radiators – become congested with metallic debris and congealed dirty water.

This causes blockages within the system, like fat in the arteries of the morbidly obese. 

The fix?
A heating engineer is going to need to flush your system – probably a power-flush to cleanse the pipework and radiators of debris and bad vibes. It’s the spa break your boiler deserves.

As a preventative measure, you should also invest in the installation of a magnetic boiler filter. A powerful magnet that attracts more filth than a pub with a flat roof.

Treating yourself to a new boiler? Heatable fit a Fernox TF1 Omega magnetic boiler filter, as standard with every new boiler installation. We even throw in a chemical treatment for your radiators. 

Common issues, for common boilers that don't work

Worcester Bosch boiler not working

Worcester Bosch Boiler Not Working

Common reasons your Worcester boilers not working & Worcester boiler error codes:

Worcester Bosch Fault Likely Error Code
Pressure too low/high A1, CE 207, H07, 224V, 1017W, 2970B
Pilot light issue (not lighting) EA, F7, FA, EA227, F7 228, FA306
Heat Exchanger error 2963 B, 2964 B, 2966 B, 2967 B
Fan Fault C6, T2, C6 215, C7 214, C1 264

Vaillant boiler not working

Vaillant Boiler Not Working

Common reasons your Vaillant boilers not working & Vaillant boiler error codes:

Vaillant Fault Likely Error Code
Pressure too low/high F.24, F.12, F.22, F.73

BAXI boiler not working

BAXI Boiler Not Working

Common reasons your Baxi boilers not working & Baxi boiler error codes:

BAXI Fault Likely Error Code
PCB (circuit board) error E100, E167, E168, H.02 - 02, 4-5 Green Flashes
Pressure too high/low E28, E119, 117, 118, 119
Pilot light error E128, E129, E384

Ideal boiler not working

IDEAL Boiler Not Working

Common reasons your Ideal boilers not working & Ideal boiler error codes:

Ideal Fault Likely Error Code
Fan defect F3
Low water pressure F1
PCB (circuit board) error F9, L9, F8, L8

Boiler still not working? Here's how you can get the best deal

How? Without boasting, buy from us.

We're an online, nationwide boiler installation business with 500+ 5 star reviews from a shed load of happy customers.

Fixed Online Boiler PricesBecause we're online, our overheads are low which means we pass those savings on to our customers, ensuring they're always getting the best deal on a new boiler. Plus, because of the volumes that we install, we're able to access exclusive warranty lengths from our partner manufacturers. For example, we can offer 10 years of protection on the Viessmann 050-W range, whereas your traditional installer can only offer you 7. Boom.

To get the best deal on a new combi boiler, answer some quick online questions and we'll give you an instant fixed price.

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