The answer depends on the age of the boiler, the cost of the repair, and the likelihood of further breakdowns. Here's how to think through it.
The 50% rule
If the repair cost is more than 50% of a replacement boiler's cost, replace it. Spending £400 repairing a 14-year-old boiler that will likely need another £300 repair next year makes no financial sense.
Age matters
- Under 7 years: Usually worth repairing — the boiler has plenty of life left
- 7–12 years: Depends on the repair cost and boiler condition
- Over 12 years: Consider replacement even for moderate repair costs — efficiency gains on a new A-rated boiler will contribute to payback
Parts availability
Older boilers can become difficult or expensive to repair as parts become scarce. If the engineer can't source parts easily, replacement may be the only option.
Efficiency gain calculation
An old G-rated boiler at 70% efficiency vs a new A-rated at 94% efficiency: on a £1,200 annual gas bill, the new boiler saves approximately £290/year. A £1,299 replacement pays back in 4.5 years in energy savings alone.
Get an honest assessment
We'll always give you an honest repair vs replace recommendation — not just the option that makes us the most money. Book a diagnostic visit.