Boiler Repair Costs: When Should I Replace a Boiler and How Much Can I Expect To Pay?

In this boiler repair cost guide, we’ll discuss when to repair your boiler and when to get a new one, and show you average costs for replacing various boiler parts. We’ll also give you some handy tips on how to protect your boiler and prolong its lifespan.

If your boiler is busted and you need an urgent replacement, you can get a no-obligation quote by filling out this 90-second, anonymous survey from Heatable. Otherwise, read on to find out more!

Boiler repair costs

Boiler Repair Costs Guide

Below, we’ve created a table that highlights the average replacement cost of boiler parts, including labour. Beware though, these numbers are just an estimate — depending on the model, brand, and type of boiler, the replacement parts will vary in price. What’s more, heating engineers in various parts of the country will charge different prices.

Boiler Part To Be Replaced

Replacement Cost

Heat Exchanger£475
Expansion Vessel£300
Diverter Valve£350
Overheat Thermostat£180
Ignition Leads£200
Gas Valve£300
Air Pressure Switch£200
Automatic Air Vent£170

If you think your boiler’s reached the end of its service life and changing parts will just prolong the mutual agony, you can also use this calculator to get a fixed boiler replacement quote from Heatable. The online installation company has great connections with the top boiler manufacturers — including Worcester Bosch — and ridiculously low overheads, so they’re able to quote you cheap. Here’s an example of a quote for costs to replace a boiler we just got online:

Worcester Bosch Greenstar i from Heatable

Boiler Repail Labour Costs — This Is What Gas Safe Engineers Charge Per Hourly

The prices in the table above are estimates for fixed-price boiler repairs. If you don’t know the problem with your boiler, it’s likely you’ll need a Gas Safe engineer to come and diagnose the problem before fitting replacement parts. The hourly rate and overall costs for a Gas Safe engineer will depend on a few things.

The first is the time of the day.

For example, is your call outside of normal working hours and considered an emergency? This is going to increase the hourly rate considerably.

The second is the part of the UK you’re based in.

Hourly rates for Gas Safe engineers in London can be almost double that of other parts of the UK.

Finally, the size of the company you find and choose to use.

Large national firms can charge 30-50% more than a local engineer.

All said, expect to pay £50-60 per hour for a boiler diagnostic. And then, expect to pay for the fixed price repair costs on top of this.

Boiler Parts: Replaced vs. Reconditioned

Some boiler parts can be reconditioned, cleaned or fixed; they don’t always have to be replaced.

A typical example might be a boiler pump that is leaking. In many cases, simply swapping the seals will fix the leak.

However, it’s worth consulting your heating engineer.

If one component in a boiler part has failed, it’s likely others will follow.

And, the time for labour is usually better spent replacing the entire boiler part, in this case, the pump.

Boiler Replacement: When To Consider A New Boiler For Your Home

There’s a few things to consider before repairing a boiler, and one is whether a replacement boiler is going to be more cost and energy effective for your home in the long run.

Deciding whether to replace rather than repair a boiler will be determined by:

  • Age of the boiler, outstanding warranty, and your boiler cover (if any)
  • The condition of expensive boiler parts
  • Cost to repair your boiler
  • Replacement cost for a new boiler
  • Boiler protection devices that are currently fitted

Want to get a fixed price on screen (no personal details needed…takes 90 seconds) before you continue reading? Jump over to this clickable form.

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#1 – Age Of The Boiler

If your boiler is 5+ years old and out of warranty, and isn’t covered by an insurance plan, it’s worth considering a replacement rather than a maintenance repair.

Boiler manufacturers place certain levels of warranty on their products for a reason; beyond the warranty they start to fail and become expensive for the consumer to run.

Likewise, most boiler cover care plans should include repairs. If you haven’t got boiler cover, then again, a new device may be a better investment than repairs. That’s because investing in boiler repairs for a unit that is on its way out is just a short-term, ‘bandaid’-type fix that won’t give your boiler back its better years. 

#2 – The Condition Of Expensive Boiler Parts

The next thing to consider is the condition of other expensive boiler parts. If they look like they are in good condition, repairing the faulty part is worthwhile.

However, if an engineer feels some or all of these parts are on their way out, a replacement should be considered.

The most expensive and important boiler parts to consider checking for wear and damage include:

  • Pump
  • Fan
  • Heat Exchanger
  • PCB
  • Burner
  • Diverter Valve

#3 – The Cost To Repair Your Boiler

Next, you’ll want to consider the cost of the actual boiler repair.

Small repairs in the £100-200 range are worth the investment.

But spending £300-500 on an old boiler, with no warranty and the chance of other components failing is a waste. If you’re in this situation, it’s time to consider a replacement.

A typical example of a part that sway many to replace their boiler rather than repair it, is a faulty or broken PCB.

A replacement PCB could cost £350-500 to install, depending on the type of boiler you have.

That’s a lot of money to be investing in an old boiler that is already proving that it’s on its last legs, and we’d be jumping straight over to here and getting a fixed price on screen.

#4 – The Cost To Replace Your Boiler

If we take a 2-3-bedroom property or home, looking for a reasonably sized combi boiler, you could expect to pay £1800-£2,500, depending on size. You can use this online boiler quote calculator to determine the exact price.

In this case, something like the Worcester 30i with a 7-year warranty would be perfect.

HEATABLE Worcester Bosch Greenstar i 30kW

Consider also, newer boilers are around 90% efficient; old boilers are not.

So, newer boiler units can offer savings of around £200 per year.

Over the course of the next 7-years, you’d actually save the majority of your investment on utility bills alone, and be covered by warranty over that period.

#5 – Boiler Protection: How Much a Warranty Will Cover

This is something a lot of people don’t consider about boilers and boiler maintenance.

There are a few ways, as a consumer, to protect your boiler:

  • Adding central heating inhibitor to break up rust and dirt in the pipes
  • Fitting a boiler filter to catch this dirt and rust
  • Installing a scale reducer to catch limescale

If none of the above are currently fitted, your boiler has been exposed.

Most manufacturer’s warranties will be void if central heating inhibitor isn’t added – that’s how important it is.

And, limescale can find its way to the heat exchanger, create hotspots, and cause it to crack.

Finally, rust and dirt (known as central heating sludge) can block not just radiators, but also parts in the boiler like the heat exchanger and pump.

Essentially, if none of the above boiler protection precautions are in place, even without a visual inspection, there’s a good chance your boiler is better off being replaced.

Once it has been replaced, fit the above devices to help protect your new boiler.

Final Thoughts — To Repair or To Replace?

If your boiler is relatively new, covered by warranty or insurance, or the replacement of parts won’t set you back more than £200, then it makes far more sense financially to try repairing your boiler first. But, of course, remember that diagnosing the problem won’t be free, either — unless it’s something self-evident, you’ll have to hire a Gas Safe engineer at the cost of roughly £50-60 per hour.

That said, if your boiler is old, out of warranty, not covered by insurance, and the repairs surpass £300, then fixing it will simply postpone the inevitable. Your patched-up boiler will rumble on for a few more months and give up the ghost. So if you feel that your repairs are just a short-term solution, don’t waste your money on them and get a new boiler instead. 

Should you decide on a replacement, I highly encourage you to get as many quotes as possible before installing. You can try your local installers, national companies like British Gas, and online installers like Heatable. If you want to get started quickly, I suggest you try Heatable first — it’ll take you less than 2 minutes to get a no-obligation quote, and all you have to do is fill out an anonymous questionnaire. You’ll find the prices to be very reasonable, and best of all, Heatable can start installing your new boiler the very next day, as long as you request service by 3pm. And even if you don’t end up using Heatable, at least their quote will serve as a handy benchmark as you get pricing from other installers. 



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  1. I have a question: can an engineer charge £77.50 + VAT per hour for labour and then still charge the time that he travelled to pick up the part to my home with telling me before that he will be charging for his travel time?

  2. Extortionate prices. I get Main or Baxi 25KW 30KW boilers supplied and fitted with smart room thermostat for £1000 to £1100

    1. From a gas safe engineer? Really? What’s their profit on the installation? Seems like £0, and there aren’t any materials costs either? 🙂
      I highly doubt you’re able to get the said prices.

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