Boiler or heating not working? All the common issues it could be and how to fix

Consumer rights expert Martyn James runs through all the tips you need to know if your boiler isn’t working

With December on the horizon and temperatures plummeting, now is the time to get to know how your heating system works.

Here are a few tips if your boiler isn’t playing ball and you are worried about the cost of an engineer. I’ll also take a look at insurance policies that cover home emergencies and ask whether they are worth it.

What to do if the heating isn’t working

I recently moved in to a new flat and for the life of me, I couldn’t get the new thermostat to work. It was stuck firm on to the wall and I couldn’t find a battery slot. No matter how I tried, I couldn’t get it working. Then I found another thermostat in a kitchen drawer. Popped in a few batteries and hurrah: heating!

So let’s be honest, do you really understand how your thermostat work? Surveys have consistently shown that of all the household devices we have, the thermostat is a mystery to many. We often set a temperature and never fiddle with the dial. Since the energy bill crisis, many more people will have got to know how their heating systems work, invested in smart thermostats or read their boiler guide. But for many people, the heating system remains little understood.

Yet every year people pay hundreds of pounds on emergency callouts due to problems with thermostats that cost less than £1 to fix. One of the most common unnecessary callouts is for thermostats that just need a battery change. That’s it! A lot of the time, people get confused by mysterious symbols flashing on the boiler, bamboozling them. That’s because your boiler isn’t getting the instructions it’s expecting. If you have an older thermostat, the connection can cut out if the batteries aren’t resting properly within the device too.

Smart thermostats can also stop working properly. There are lots of different types of smart thermostat, but as a very general rule, a blinking screen usually means the system is doing something important, like downloading software, is frozen or not functioning properly. Your guide will tell you how to reboot the thermostat and troubleshoot the problem. Why not photo the screen before you do so then take the time to read the guide thoroughly to identify what the flashing codes or symbols mean. Some smart thermostats can be USB charged too. You’ll also find the inevitable YouTube guides too.

If your boiler is still playing up, run a few basic checks, like turning the dials and thermostat down, pressing the ‘boost’ option and seeing if the boiler kicks into life. Repressurising the boiler can be a bit nerve wracking if you’re not technically minded, but it’s a relatively simple process for most boilers. Don’t launch straight into it though. Read the steps first and make sure you are confident with the process. Don’t forget to turn the boiler off as water may leak and it could be hot.

You may not be able to find the boiler guide, or like mine, it’s an installation guide and incomprehensible. You can find most guides online – look for the boiler number (often on the underside) if you’re not sure – and there are loads of YouTube guides to basic problems too. I hate to state the obvious, but only attempt simple things like repressurising the boiler. Do not attempt to dismantle the thing, no matter what it says on YouTube.

If your radiators aren’t heating up properly then you might need to ‘bleed’ them. This is where air becomes trapped in the system which can have an impact on how much heat the radiators are generating. Again, this can seem rather complicated if you’ve not done it before but it’s actually quite easy. Most energy companies have guides on how to do this online. If you’ve lost your radiator key, they’re often quite generic and easy to replace. It’s recommended that you bleed your radiators once a year even if they seem to be working fine. Don’t go rushing straight in to this though. You’ll need to turn off the heating, wait for it to cool down and make sure you’ve got a bowl and towel handy for any leakage. I use the turkey cooking tray, which means it gets a clean afterwards before Christmas!

If you think you need to make a claim on a boiler or home emergency policy, check first to see what you’re covered for. Most have 24-hour call out lines and a long list of things covering your rights and timescales on repairs and replacements. That way you are prepared for any hidden costs and know your rights if there are delays with repairs. You may also have some home emergency or boiler cover through your home and contents insurance policy, so give the insurer a call before commit to an emergency callout.

If you’ve got blocked or leaking pipes, check if you can to see whether the pipes are on your property (claim through your insurer) or outside it (usually the water company needs to sort this out). Confirming access points can save a lot of hassle should you ever need to make a claim. Have a look around your home for wet or discoloured patches or sniff out strange smells. If you live in a communal property then speak to your landlord or building management committee about their building insurance.

Boiler and home emergency cover

Is it worth taking out a policy to cover boiler breakdowns? Costs for calling out an engineer can be pricey and can increase quite a bit depending on what’s gone wrong. It’ll cost around £225 to £675 according to Check a Trade for an emergency callout, though that doesn’t cover all the work that might be required. Annual boiler servicing can be between £80 to £120. All of this might make you consider paying extra for a specialist boiler or home emergency insurance policy.

A few years ago you could fork out £300 or more for some insurance policies, which meant that there was a good argument for just putting that money to one side to save you some more money in the long run. However, if you have a look online now, you’ll find some policies covering just your boiler for as little as a couple of pounds a month. Watch out though, as they vary significantly.

These cheap quotes suddenly become a lot more expensive as you enter in the details of your home. Even moderately priced policies come with catches. For example, one of the big boiler cover businesses starts prices at just under a tenner a month. But you’ll pay a call out fee of over £100 per callout. A policy with unlimited free callouts will set you back over £200 a year. So the actual price you’re paying if you need to make a claim is higher than you might think.

In addition, not all boiler contracts are insurance products. Some are ‘regulated’ insurance contracts and others are ‘service contracts’ – which matters because if there’s a dispute, you can’t go to the Financial Ombudsman if it’s a service contract or an unregulated agreement. An insurance policy will list the underwriter – the firm that investigates and pays out claims.

So what do you need to watch out for it you’re buying a boiler or home emergency policy? Aside from the type of contract and the emergency call out fees, look for a 24 hour, 365 days a year emergency helpline. Keep an eye out for the initial ‘no claims’ period when you can’t make a claim (usually around two weeks after signing the contract). There are also call out limits with some policies and caps on parts, repairs and labour.

If your boiler is over seven years old, you might find your policy might not cover you. And if you already have home and contents insurance in place, ask your insurer how much an add on home emergency or boiler policy might cost as they’ll already have the details of your home and might be able to give you a better deal.

Turning the boiler back on

Don’t be like me and hold out until the last minute before turning the boiler back on. Most experts suggest cranking up the boiler for a short while a few times over the next month, to help identify any problems and avoid damage to pipes. Keep the thermostat low while you do this (though not so low you can’t tell if the heating is on!) And if you go away for Christmas, don’t switch the boiler off, just turn the thermostat down to a lower level.

• Martyn James is a leading consumer rights campaigner, TV and radio broadcaster and journalist