Boiler replacement in London

Age, the cost of the part that has failed, and whether parts are still available. Over roughly twelve years old with an expensive failure usually points to replacement; under that, repair normally wins.

Yes, always, where a repair is possible. You should be comparing two numbers, not being handed one.

Yes, and a replacement is the natural moment to do it. Moving it adds pipework and flue work to the job, but it is often the fix for a problem you have lived with for years.

Not necessarily — a replacement is exactly the point to reconsider that. If the house has gained a second bathroom since the current boiler was fitted, a system boiler with a cylinder may now suit it better than another combi.

It can be, if the boiler is old, unreliable and parts for it are getting scarce. Replacing on your own timetable means you can compare quotes calmly and pick a time outside the coldest weeks, rather than accepting whatever is available during a January breakdown. But a boiler that is old and still running well does not need replacing on age alone, and we will tell you if yours is in that position.

Often, if the old one is a non-condensing boiler from before the mid-2000s, because modern condensing boilers turn more of the gas into heat. How much you notice depends on how the system is controlled and whether the radiators are sized so the boiler can run at lower temperatures. A new boiler on a system with no thermostat and sludged-up radiators will save far less than the brochure suggests.