Guide
How long does it take to fit a new boiler?
The honest answer is that it depends, but not by as much as you might fear. Here is the range and what moves you along it.
Short answer
A boiler installation takes 1 to 4 days depending on the circumstances. A straight like-for-like swap is at the short end. Bathroom plumbing takes around 3 to 4 days.
What puts you at the short end
A like-for-like combi swap, boiler staying where it is, existing pipework and flue in usable condition. Nothing gets moved, nothing gets stripped out. You are off heating and hot water for the working day and back on that evening.
This is the most common job we do and it is the one most people are picturing when they ask.
What pushes it towards four days
Moving the boiler to a different room, which means running new gas, water and flue.
Changing system type, for instance removing a hot water cylinder and loft tanks to convert to a combi. That is a strip-out as well as an installation.
Awkward flue routing, which in tenements is the usual culprit.
Anything that turns up once the old boiler is off the wall. Old pipework in poor condition does not announce itself in advance.
How long you are actually without heating
Less time than the job takes. On a multi-day install we are not usually leaving you without hot water for the full duration, and where we can stage the work to keep you running overnight we will.
If you are elderly, have young children or anyone in the house is vulnerable to the cold, say so when you book. It changes how we sequence the work and it is not a problem to plan around.
Bathrooms
The plumbing for a bathroom normally takes around 3 to 4 days.
Worth being clear about what that covers: we do the plumbing. The suite, the showers, the brassware, the towel rails, all fitted properly. We do not tile or plaster. If you need those trades as well, you will need them booked around us, and we would rather tell you that up front than half-do it.
Prices shown are guide prices and exclude VAT. Last updated 4 August 2026. The final figure for any job is confirmed after a free survey.