Boiler Repair vs Replacement: How to Decide (2026 Cost Comparison)
How Much Does a Boiler Repair Cost?
The cost of a boiler repair depends on the fault. Here are typical repair costs in the UK for 2026, including parts and labour.
| Common Fault | Typical Cost (parts + labour) |
|---|---|
| Ignition / pilot light failure | £100–£300 |
| Fan or pump replacement | £200–£400 |
| PCB (circuit board) replacement | £300–£500 |
| Heat exchanger replacement | £400–£600 |
| Diverter valve replacement | £200–£350 |
| Gas valve replacement | £250–£400 |
| Thermostat or sensor fault | £100–£250 |
| Leak from boiler body | £150–£400 |
Prices are estimates for 2026 and include labour. For a full breakdown of plumber rates, see our plumber costs guide.
How Much Does a New Boiler Cost?
New boiler prices depend on the type of boiler, whether it is a straightforward swap or involves moving the boiler, and the complexity of the pipework.
| Boiler Type | Typical Cost (supplied + installed) |
|---|---|
| Combi boiler (like-for-like swap) | £2,000–£3,500 |
| Combi boiler (new location / pipework changes) | £3,000–£4,500 |
| System boiler with cylinder | £3,000–£5,000 |
| Regular (heat only) boiler | £2,500–£4,000 |
| Boiler conversion (e.g. regular to combi) | £3,500–£5,500 |
Prices are estimates for the Exmouth and East Devon area. Get a quick estimate with our cost calculator. Not sure which boiler type you have? Read our combi vs cylinder guide.
When to Repair Your Boiler
Repairing usually makes sense when the boiler is relatively new, the fault is isolated and the cost is reasonable.
Boiler is under 10 years old
Modern boilers have a lifespan of 12 to 15 years. If yours is under 10, repairing is almost always the better option unless the fault is catastrophic.
Repair cost is under £400
As a rule of thumb, if the repair costs less than a third of a new boiler installation, it is worth fixing. Most single-component repairs fall well under this threshold.
This is the first major fault
Every boiler will develop a fault eventually. A single repair on an otherwise reliable boiler is no reason to replace it.
Parts are readily available
If your boiler model is still in production or well supported, parts are easy to source. Your Gas Safe engineer can confirm this quickly.
When to Replace Your Boiler
Replacement makes more sense when the boiler is old, unreliable or costing you more in repairs and wasted energy than a new one would.
Boiler is over 12–15 years old
Older boilers become less efficient and more prone to breakdowns. A boiler from 2010 or earlier is likely running at 70–80% efficiency compared to 90–94% for a modern condensing boiler.
Repeated breakdowns
If you have had two or more callouts in the past 12 months, the boiler is telling you it is reaching end of life. The cumulative cost of repairs often exceeds the cost of replacement.
Repair cost exceeds £500
A heat exchanger or PCB replacement on an older boiler can cost £400 to £600. At that point, putting the money towards a new boiler with a 5 to 10 year warranty is usually better value.
Parts are discontinued
If the manufacturer no longer makes parts for your boiler model, repairs become expensive and unreliable. Second-hand parts carry no guarantee and may fail again quickly.
Energy bills are climbing
An old, inefficient boiler wastes gas. Upgrading from a 70% efficient boiler to a 93% efficient model could save £200 to £300 per year on gas bills — the new boiler pays for itself over time.
Boiler Efficiency by Age: What You Are Paying
Older boilers waste more gas. This table shows how efficiency drops with age and what that means for your annual gas bill.
| Boiler Age | Efficiency | Est. Annual Gas | Notes |
|---|---|---|---|
| New condensing boiler (2024–2026) | 90–94% | £750–£850 | ErP A-rated, modulating output |
| Boiler 5–10 years old | 85–90% | £850–£950 | Early condensing models, still efficient |
| Boiler 10–15 years old | 78–85% | £950–£1,100 | Efficiency drops as components wear |
| Boiler 15–20+ years old | 65–78% | £1,100–£1,350 | Non-condensing, significant waste |
Annual gas estimates are based on a typical 3-bed semi-detached house at 2026 energy prices. Your actual costs will vary with home size, insulation and usage patterns.
Quick Decision Checklist
Use this at-a-glance checklist to help you decide. If most of your answers fall in the "Replace" column, it is probably time for a new boiler.
| Question | Repair | Replace |
|---|---|---|
| How old is your boiler? | Under 10 years | Over 12–15 years |
| How much will the repair cost? | Under £400 | Over £500 |
| How many breakdowns in the past year? | 0–1 | 2 or more |
| Are parts still available? | Yes, readily | Discontinued or scarce |
| Current efficiency rating? | 85%+ (A or B rated) | Below 80% (D, E or unrated) |
| Is your warranty still valid? | Yes — repair is covered | Expired |
Boiler Repair vs Replacement: FAQs
Need a Boiler Engineer?
Browse our directory of Gas Safe registered plumbers covering Exmouth, Sidmouth, Budleigh Salterton and East Devon. Get a quote for a boiler repair or a new boiler installation.
For more on boiler issues, see our boiler repair guide. Wondering which boiler type is right for your home? Read our combi boiler vs cylinder comparison. Check Gas Safe plumber requirements before hiring.