Boiler replacement
Back boiler removal and replacement
Still got a boiler behind the gas fire? They were built to last and many still work, but parts are drying up. Better to plan the change than have it forced on you mid-winter.
- Gas Safe 951167
- Free survey
- Fixed written quote
- 12-month guarantee
Why people change them now
Back boilers were well made and a lot of them are still running after forty years. The reason to act is not usually that the appliance has failed. It is that the supply chain behind it has.
- Parts. Spares are increasingly scarce. A fault that used to mean an afternoon's work can now mean the appliance is finished.
- Running cost. They are not condensing appliances, so a significant share of the heat goes up the flue.
- Space. Removing one gives you back the chimney breast and, on most systems, the airing cupboard too.
- Timing. If it fails in the cold, you are choosing a boiler in a hurry with no heating. Choosing in summer is a different experience.
If yours is working and safe, we will tell you that and tell you roughly how long parts are likely to remain available. Knowing where you stand is worth more than a quote you did not ask for.
Wall-mounted combi boiler installed and commissioned by our Gas Safe engineersOur own work · Gas Safe 951167
What the job involves
This is a bigger piece of work than a like-for-like swap, and we would rather set the expectation properly than surprise you on day two.
- Survey first, including where the new boiler can realistically go and how the flue will run.
- The old appliance and gas fire come out of the chimney breast, and the gas supply is capped and made safe.
- The new boiler is fitted in its new position, usually a kitchen or utility, with pipework rerouted to suit.
- The system is cleaned before the new boiler goes on, because decades of debris would otherwise land in the new heat exchanger.
- Everything is commissioned, registered with Gas Safe, and you get the paperwork.
You get a free survey and a fixed written price before anything starts, and that price is what you pay. See also boiler replacement and power flushing.
Common questions
What is a back boiler?
A boiler sited in the chimney breast behind a gas fire, common in homes built or modernised from the 1960s to the 1980s. The fire is the visible part; the boiler doing the heating sits behind it. They are no longer manufactured for new installations.
Do I have to remove it?
Not if it is working and safe. There is no rule forcing removal. The practical pressure is parts: they are increasingly hard to source, so a fault that would once have been a straightforward repair can now end the appliance. It is better to plan the change than to be forced into it in January.
What replaces it?
Usually a modern condensing boiler somewhere more sensible, often a kitchen or utility, which frees up the chimney breast and the airing cupboard. Whether that is a combi or a system boiler depends on how many bathrooms you have and how you use hot water.
What happens to the fireplace?
Once the appliance is out, the opening can be left ready for a fire or made good and plastered over. We will make the gas safe and cap it, and be clear from the start about what is included and what is builder work.
Is it a bigger job than a normal swap?
Yes, and we will say so up front. The old appliance has to come out of the chimney breast, the flue arrangement changes, the new boiler goes somewhere different, and the pipework has to be rerouted. It is normally a multi-day job rather than a day.
Does the system need cleaning at the same time?
Almost always. A system that has run on a back boiler for decades will be carrying a lot of debris, and putting a new boiler onto it without cleaning pushes that straight into the new heat exchanger. Most manufacturers require the system to be cleaned for the warranty to stand.
Got a back boiler you are unsure about?
We will come and look, tell you honestly whether it is still supportable, and give you a fixed written price if it is time to change it.