Boiler repair vs cover vs replacement

When you experience boiler trouble it can be tricky to know what to do – whether that's fixing the problem, paying for boiler cover, or replacing the boiler altogether. To give you some guidance, we've pulled together a few scenarios, costs, and considerations for many eventualities so you won't end up replacing a perfectly decent boiler before you need to.

Boiler fitting cost


Cost of boiler replacement

If you have water pressure issues

In many cases you'll be able to diagnose and fix this problem yourself. But if you've followed our guide on boiler pressure issues and you still can't get to the bottom of it, you'll need to call out an engineer. Depending on what the problem turns out to be and the call-out fee charged by engineers in your area, a repair is likely to be more economical than replacement or cover.

Price for boiler replacement

If your radiators aren't heating properly

You might only need to bleed them, which is free! Or it could be that deposits have built up in your system, hampering its performance. So if you’ve tried bleeding the radiators without success, a Gas Safe engineer can arrange a chemical Powerflush before any major damage is done. Powerflushes are far more cost effective than replacing the boiler, so try this first. If extensive corrosion has already occurred, it might be less straightforward. We’ll come back to this later.

Gas boiler cover vs replacement

If the issues are minor or low-cost

The ten most common boiler faults had an average repair price ranging from £85 to £259, according to Which? Among the cheapest to repair were a Thermocouple at £85, an Automatic air vent at £98, and a boiler ignition at £106. So if your boiler still has a few years of safe and efficient service left in it, it’s worth having an engineer fix the small problems before you consider cutting your losses.

Average cost to fix a boiler


Baxi boiler service cost

If your boiler is more than 5 years old or out of warranty

As your boiler ages it might need a little more TLC, so annual cover is a worthwhile consideration. A new gas or oil boiler will typically cost between £500 and £2,407, according to May 2017 figures from a survey by Which? of all boiler manufacturers in the UK with a greater than 1% market share.

Prices vary depending on whether you're buying a combi, heat-only or system boiler, and according to the heat output of the boiler. You should contact a Gas Safe boiler installer for a list of the latest prices and offers.

Boiler cover, on the other hand, with British Gas HomeCare One protection costs from £144 a year, so it's worth looking at the price of new boilers in the context of cover. A new boiler costing £2,407 equates to more than 16 years of HomeCare One protection at its current prices.

Boiler replacement costs


Warm air heating service

If your boiler breaks down from heavy corrosion

If your boiler isn't serviced regularly, impurities and acidity in the water can eat away at its internal electrics and seals. When this happens, efficiency will suffer and repairs are likely to be extensive – meaning a replacement might make more sense.

Signs of rust or corrosion on the outer casing, seams, or water inlet of your boiler suggest that there's an issue. So have a Gas Safe engineer take a look for you.

Is boiler cover worth it

If your old cast-iron boiler suffers a water leak

While a leaky modern boiler is often straightforward to fix, cast-iron boilers present a different challenge. If a leak is caused by a crack in the iron body, the boiler will most likely need to be dismantled and the extra labour will really bump up the repair fee. With that in mind, it could be better to replace the boiler with a new one. See our guide to the different types of boiler, for more on this.

Should you take out boiler cover

If your boiler combustion is very poor

Poor combustion poses a risk of carbon monoxide leakage, fire and even explosion. So if you see telltale signs such as soot on your boiler (or in the immediate area), or the pilot light keeps blowing out, have it inspected by a Gas Safe engineer right away.

They might "condemn" the boiler, but don't panic. Frightening as this sounds your engineer will make sure everything's safe, before advising you of the next step which — for safety's sake — might be a replacement.

How expensive is it to repair a boiler

If your flue is dangerous

Your entire flue, along with your boiler, needs to be inspected annually to make sure it fulfils safety standards. All modern gas boilers have flues with inspection hatches and so meet current Gas Safe Regulations, but if your boiler is older and has a concealed flue (in a ceiling or wall void) your Gas Safe engineer must mark it as "at risk" during its annual inspection. This is because they're unable to check its whole length and so can't confirm it won't become dangerous. They'll also recommend that you no longer use your boiler.

You may need to put in inspection hatches, resituate your boiler in your home or install a new flue – or all three –  depending on your current installation. When you add up the cost of the work, it could end up costing as much as a full installation. If it does, it's worth considering a boiler upgrade.

Remember, your trusted Gas Safe engineer will always be the best person to advise you on your individual circumstances. So if you're unsure about any aspect of your boiler's performance, or safety, you can book a heating consultation here or see our guide to finding your own trusted Gas Engineer.