Boilers
Should I repair or replace my boiler?
3 min read · Reviewed for accuracy before publishing
The rule of thumb: under about 10 years old with a single, non-major fault — repair. Over 12–15 years, or facing a big-ticket part (heat exchanger, PCB, fan) on top of rising bills and repeat call-outs — replacement usually wins on total cost within a couple of years. The two questions that settle most cases: is the failed part a major one, and are parts still available for your model? A discontinued boiler needing a heat exchanger is a replace; a five-year-old boiler needing a diverter valve is a repair. We quote both, every time, and let you choose with the real numbers.
When repair is the right call
A relatively young boiler (say, under 10) with a well-defined, cheaper fault — a valve, a sensor, a pump — is worth repairing. It's sound, parts are available, and a new boiler wouldn't pay for itself. Replacing it would be selling you something you don't need, which we won't do.
When replacement wins
Age past 12–15 years, a major component failure, discontinued parts, falling efficiency and repeat breakdowns for different faults — any two of those together and the maths tips. A new A-rated boiler with a long warranty often pays back a meaningful slice of the install cost each year in gas savings, before you count the avoided emergency call-outs.
The honest number we give you
We diagnose the actual fault, then quote the repair and a like-for-like replacement side by side — including the efficiency difference and the warranty you'd gain. No pressure, no scare tactics; the decision is yours, made on real figures rather than a doorstep sales pitch.
Get the repair-vs-replace numbers →
David founded Datum after years on the tools across heating and plumbing. He writes the boiler and cost guides from what actually happens on real installs.