How Long Does Boiler Installation Take?
Realistic timescales for each type of boiler installation, from a same-day straight swap to a full system conversion.
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A straightforward like-for-like boiler replacement is usually completed within a single working day. More involved installations take longer, with a conversion or relocation typically runs to two or three days.
Here is what determines which category your job falls into.
Straight swap: usually one day
Replacing a boiler with the same type in the same position, where the existing pipework and flue route are suitable, is a one-day job in most properties.
The old appliance comes out, the new one goes on, the system is cleaned and refilled, and the boiler is commissioned and handed over. You will be without heating and hot water for the working day but should have both back by the evening.
Boiler relocation: two to three days
Moving a boiler to a different wall or room means running new gas, water and condensate pipework to the new position and creating a new flue route. Old pipework has to be capped or removed, and the new runs need to be routed sensibly rather than surface-mounted across a kitchen.
This is more disruptive and takes longer. It also frequently involves lifting floorboards, so allow for making good afterwards, which is not included unless specifically quoted.
System conversion: two to three days
Converting from a regular boiler to a combi involves removing the hot water cylinder, decommissioning and removing loft tanks, altering the pipework throughout, and changing the controls.
There is more to take out than there is to put in, and the work touches more of the house. Expect two to three days for most properties, and remember that plastering, tiling and decorating where the cylinder and tanks were is a separate job.
What can extend the timescale
- Undersized gas supply requiring a new run from the meter
- Concealed pipework in poor condition that only becomes visible once work starts
- Heavily contaminated systems needing a full power flush
- Difficult access, such as loft installations, tight cupboards, upper-floor positions
- Asbestos, which stops work immediately until specialist advice is obtained
- Unsafe existing electrical supply to the boiler position
We identify as much of this as possible at survey so the timescale we give you is realistic rather than optimistic.
Will I be without heating and hot water?
Yes, for the duration of the installation. On a one-day swap that means a single day. On a longer job we will discuss what we can restore overnight where it is safe and practical to do so.
If you have particular concerns, such as young children, elderly residents, medical needs, tell us at survey and we will plan around it.
Frequently asked questions
How long does it take to replace a boiler?
A like-for-like replacement in the same position is usually completed within one working day. Conversions and relocations typically take two to three days.
Will I have no heating during the work?
Yes, for the duration of the installation. On a single-day swap heating and hot water are normally back the same evening.
Do I need to be home the whole time?
We need access throughout, and someone should be present at the end for the handover and demonstration.
What if the job takes longer than quoted?
If genuinely unforeseen problems are uncovered we stop and discuss them with you before continuing. We do not carry out extra chargeable work without agreeing it first.