How long does a boiler last — and when should I replace mine?
A decent modern boiler, serviced annually, lasts 12–15 years — some soldier on longer, but efficiency falls and parts get scarcer and pricier past that point. The rule of thumb: under 10 years old with a single fault, repair; over 12–15 with rising bills, repeat faults or discontinued parts, replacement usually wins on total cost within a couple of years. The worst option is the one most people choose: waiting for the fatal breakdown on the coldest week of the year.
The warning signs worth acting on
Repeat call-outs for different faults, yellow or lazy flame behaviour flagged at service, rising gas use for the same warmth, pressure that won't hold, and parts on back-order. Any two of those together is the boiler telling you its plans.
Why efficiency shifts the maths
An ageing non-condensing or early condensing boiler can run well below modern efficiency. On a typical family gas bill, upgrading pays back a meaningful slice of the install cost every year — before you count the avoided emergency call-outs.
Planned beats emergency, every time
A planned replacement is a surveyed, fixed-price, one-day job with the right boiler chosen calmly. An emergency replacement is whatever's in stock, fitted at distress speed, in a cold house. Same boiler, very different experience and price.