The easier way to book quality trades

Download app

There’s a particular kind of dread that comes with a boiler suddenly playing up.

Maybe the heating won’t come on. Perhaps the pressure keeps dropping. Or you wake up to a freezing house and no hot water, immediately wondering whether this is going to be a straightforward repair... or the start of a very expensive replacement.

The good news is that many common boiler faults can be repaired without replacing the entire system.

This guide breaks down typical boiler repair costs in the UK, including emergency call-out prices, common faults, what affects repair costs, and when it may make more sense to consider a replacement boiler instead.

How much does a boiler repair cost?

As a rough guide, boiler repair costs usually range from around £120–£750, depending on the type of fault, the boiler model, and whether replacement parts are needed.

Most homeowners spend around £300 on average for a typical boiler repair, including parts.

How much should a boiler repair cost?

For most common faults, boiler repair costs in the UK tend to sit somewhere between £100–£500.

Smaller jobs, such as replacing a valve or fixing pressure issues, are often at the lower end of the scale.

More complex repairs involving major parts, emergency call-outs, or older boilers usually cost more.

In many cases, repairing a boiler is still significantly cheaper than replacing it entirely.

Get boiler repair quotes near you

If your boiler’s started making strange noises, leaking, losing pressure, or failing to heat your home properly, it’s worth getting it checked sooner rather than later.

A qualified boiler engineer can safely assess your boiler, identify the fault, and tell you whether a repair is likely to solve the issue or whether replacement may be more cost-effective in the long run.

Find checked boiler engineers working in your area and compare boiler repair quotes.

Boiler repair costs at a glance

• Average boiler repair cost (UK): Around £300

• Emergency boiler repair cost: Around £450

• Gas engineer hourly rate: Around £50–£80 (+ repairs and parts)

• Boiler service cost: Around £80–£120

• Boiler insurance: Around £15 per month

• Gas valve replacement (labour + materials): Around £180–£220

• Kettling boiler repair: Around £300

Common boiler problems and repair costs

Not every boiler fault means your whole heating system is failing.

Sometimes the issue turns out to be fairly minor — trapped air, low pressure, or a worn part that’s reached the end of its life. Other times, especially with older boilers or systems that haven’t been serviced regularly, the repair can be a bit more involved.

Here are some of the most common boiler problems homeowners run into and what repairs typically cost.

Gas valve replacement cost

Over time, a gas valve can become stuck, worn or rusted.

Typical gas valve replacement cost: around £180–£220 including labour and materials.

Signs you may have a gas valve issue include:

• Boiler failing to ignite

• Inconsistent heating

• Boiler locking out

• Unusual clicking noises

Because this involves gas components, repairs must always be carried out by a Gas Safe registered engineer.

Kettling boiler repair cost

Boiler kettling is when your boiler starts making loud whistling, rumbling, banging or popping noises.

Typical kettling repair cost: around £300.

Kettling is commonly caused by:

• Limescale build-up

• Overheating

• Trapped air

• Circulation issues

• Internal blockages

It can sound alarming, but it’s often repairable if dealt with early.

Leaking boiler repair cost

A leaking boiler can be caused by anything from loose seals to pressure problems or failing internal components.

Repair costs vary depending on the source of the leak and whether any parts need replacing. Smaller leaks are often straightforward repairs, while older boilers with corrosion issues can become more expensive.

Leaks should never be ignored, as water damage can affect nearby electrics and internal components.

Boiler flue replacement cost

Your boiler flue is the pipe that safely carries waste gases from your boiler to outside your home. If it becomes damaged, blocked or unsafe, it’s important to get it checked quickly.

As a guide, the average boiler flue replacement cost for a straightforward horizontal flue is around £200.

Costs can increase if:

• Access is difficult

• The flue route needs altering

• Scaffolding is required

• Additional boiler safety work is needed

Low boiler pressure repair

If your boiler keeps losing pressure, the issue could be:

• A leak somewhere in the system

• A faulty pressure relief valve

• Expansion vessel problems

• Hidden pipework leaks

• Recently bled radiators that haven’t been repressurised properly

Sometimes repressurising the system solves the issue temporarily, but recurring pressure loss usually needs investigating properly.

Boiler not heating water properly

If your hot water keeps cutting out or your radiators stay lukewarm, common causes include:

• Faulty thermostats

• Pump problems

• Airlocks

• Diverter valve issues

• Sludge build-up

These faults are common across combi boilers and conventional heating systems.

Electric boiler repair issues

Electric boilers don’t use gas, so they avoid some gas-related faults, but they can still develop issues such as:

• Thermostat failures

• Heating element problems

• Electrical faults

• Pump failures

• Pressure issues

Condensing boiler repair issues

Modern condensing boilers are efficient, but they can sometimes experience:

• Frozen condensate pipes

• Pressure fluctuations

• Ignition problems

• Sensor faults

Frozen condensate pipes are particularly common during very cold weather.

Emergency boiler repair cost

If your boiler breaks down completely during winter (especially if you have no heating or hot water) you may need an emergency boiler repair.

Emergency boiler repair prices usually range from around £225–£675, with average emergency repair costs sitting around £450.

Emergency repairs often cost more because engineers may be working unsociable hours.

Parts are usually charged separately too, which can significantly increase the final bill.

Signs your boiler may need repairing

Boilers rarely fail completely without warning.

Often, there are smaller signs first that something isn’t quite right.

Common warning signs can include:

• Banging or clanking noises

• Leaks

• Losing pressure

• Boiler repeatedly switching itself off

• Strange smells

• Radiators not heating properly

• Hot water cutting in and out

• Pilot light issues (on older gas boilers)

Catching boiler issues early can sometimes mean a much smaller repair bill.

Common boiler parts that may need replacing

Although boilers look fairly simple from the outside, there are lots of internal parts working together behind the scenes that control the central heating and warm water flow.

Some of the most commonly repaired or replaced boiler parts include:

• Gas valves

• Fans

• Heat exchangers

• Printed circuit boards (PCBs)

• Flues

On Checkatrade, you'll only find trades who meet our high standards and pass up to 12 checks.

What affects boiler repair costs?

No two boiler repairs are exactly the same.

The main factors that can affect boiler repair costs include:

• Type of fault: Simple issues cost far less than major internal component failures

• Boiler age: Older boilers can be harder to repair because replacement parts may be difficult to source

• Boiler brand: Parts prices vary between manufacturers

• Boiler type and size: Larger or more complex systems can cost more to repair

• Replacement parts needed: New components increase the overall repair bill

• Labour time: Some engineers charge hourly, while others quote fixed repair prices

• Emergency call-outs: Out-of-hours repairs usually cost more

• Warranty or insurance: Some repairs may already be covered

Additional boiler repair costs to budget for

The repair itself may not be the only cost involved.

Depending on the issue, you may also need to budget for:

• Diagnostic fees

• Emergency call-out charges

• Replacement parts

• Boiler servicing

• System flushing

• Access equipment

• Parking charges

• Temporary heating solutions

• Upgrading older components

• Boiler replacement if repairs aren’t economical

Sometimes engineers may only discover additional issues once the boiler has been opened up and inspected properly.

Boiler servicing vs boiler repairs

Boiler servicing and boiler repairs are related, but they’re not the same thing.

• A boiler service is preventative maintenance designed to keep the boiler running safely and efficiently

• A repair happens when something has already gone wrong

Regular servicing can sometimes spot worn parts before they fail completely, helping reduce the risk of unexpected breakdowns later (and you waking up to no heating or hot water on a cold winter’s morning).

Typical boiler service cost: around £80–£120.

When is it worth replacing a boiler instead?

Sometimes a repair is the sensible option. Other times, replacement becomes more cost-effective.

Boiler replacement might be something you want to consider if:

• Repairs are becoming frequent

• Replacement parts are difficult to source

• Your boiler is very old

• Efficiency is poor

• Repair costs are starting to add up

• Your heating bills keep rising

If replacement is starting to feel more realistic than another repair, take a look at our guides to the best boilers for central heating and finding the best boiler brands.

What should be included in a boiler repair quote?

A clear boiler repair quote should explain:

• Diagnostic or call-out fees

• Labour costs

• Replacement parts

• VAT, if applicable

• Whether the repair is guaranteed

• Estimated repair times

• Whether additional work may be needed

• What isn’t included

Can you repair a boiler yourself?

Boiler repairs are not usually suitable DIY jobs.

Gas boiler repairs must legally be carried out by a Gas Safe registered engineer. Working on gas appliances without the correct qualifications is dangerous and illegal.

Even non-gas systems can involve:

• High temperatures

• Electrical components

• Pressure systems

• Water damage risks

A poor repair now can easily turn into a much bigger (and more expensive) problem later on.

Carbon monoxide and boiler safety

Carbon monoxide risks mainly apply to gas, oil and solid-fuel appliances — not electric boilers.

Faulty boilers, blocked flues or poorly maintained heating systems can potentially leak carbon monoxide, which is extremely dangerous because it has no smell or colour.

Possible symptoms include:

• Headaches

• Dizziness

• Nausea

• Breathlessness

Installing a carbon monoxide alarm near gas appliances is strongly recommended.

Boiler repair cost calculator

Use our boiler repair cost calculator if you'd like a rough idea of what your repair might cost before contacting local engineers.

You’ll need to think about the type of boiler and its age, the fault or symptoms, and whether it’s an emergency.

Job Estimate Calculator

Get Started

Step 0/3

This calculator provides a guide price only, not a quote. For an accurate figure, ask a checked local boiler engineer to inspect the boiler and provide an itemised quote.

Boiler repair cost checklist

• Check whether your boiler is still under warranty

• Ask whether there’s a call-out or diagnostic fee

• Compare a few itemised quotes where possible

• Ask whether parts are included in the quote

• Check whether the repair is guaranteed

• Confirm whether emergency rates apply

• Ask whether servicing is recommended afterwards

• Make sure your engineer is Gas Safe registered

• Get the full repair scope in writing

When should you speak to a boiler engineer?

It’s worth speaking to a boiler engineer as soon as your boiler starts showing signs of trouble — even if the heating is still technically working.

Strange noises, leaks, pressure problems, unreliable hot water, or repeated shutdowns are all worth investigating early.

A good engineer can explain:

• Whether the fault is repairable

• What’s causing the issue

• Whether replacement parts are available

• Whether repair or replacement makes more sense financially

In many cases, it’s better to catch boiler problems early before they lead to a full breakdown, which is usually more disruptive, more stressful, and potentially more expensive to repair.

Every Checkatrade job is backed by our £1,000 guarantee

Up to £1000. Eligibility criteria and T&C’s apply.

Find boiler repair engineers near you

Comparing quotes from local boiler engineers is one of the best ways to understand what a fair boiler repair cost looks like in your area.

A good engineer should assess the problem properly, explain what’s involved clearly, and provide a written quote before carrying out major repair work.

FAQs

How much should a boiler repair cost?

Most boiler repairs cost somewhere between £100–£500, depending on the fault and any replacement parts needed. More complex or emergency repairs can cost more.

How much does a boiler repair cost in the UK?

The average boiler repair cost in the UK is around £300, although prices can range from around £120–£750 depending on the issue.

How much does emergency boiler repair cost?

Emergency boiler repair costs usually range from around £225–£675, with average emergency repair prices sitting around £450.

How much does it cost to repair a leaking boiler?

Leaking boiler repair costs vary depending on the source of the leak and whether replacement parts are needed. Smaller leaks are often cheaper to repair than internal corrosion or pressure-related faults.

Can a boiler usually be repaired?

Many common boiler faults can be repaired without replacing the whole boiler, especially when the issue is caught early.

Does boiler servicing reduce the need for repairs?

Regular servicing can help spot worn parts or developing faults before they become more serious. Annual servicing is also often required to maintain boiler warranties.

How much does boiler insurance cost?

Boiler insurance usually costs around £8–£30 per month, with average prices sitting around £15 per month.

Can I get help with boiler repairs?

In some situations, support may be available through warranties, boiler insurance, landlord responsibilities, or local grant schemes. It’s worth checking what cover or support you already have before paying for repairs yourself.

Is it worth repairing an old boiler?

It depends on the age of the boiler, the repair cost, and how often problems are happening. If repairs are becoming frequent, replacement may sometimes make more financial sense.

How quickly can a boiler be repaired?

Some repairs can be completed the same day if parts are readily available. More complex repairs or older boilers may take longer if specialist parts need ordering.

Checkatrade

Follow us

More Gas Boiler Servicing / Repair Articles

How much does a new boiler cost in the UK in 2026?

Boiler service costs in the UK (2026 price guide)

Central heating installation cost in the UK in 2026

View all