Does a boiler have to be on an outside wall

Starting to think about doing a kitchen remodel and would like to move our boiler out of the kitchen. Does it have to be installed on an outside wall? What are our options?

Asked by Jenny on 24th Dec 2025
Expert Trade Answers
"Boiler can be sited in many places inside the house. A flue must be fitted according to the manufacturers instructions and comply with gas safety regs. The limitations are that the flue length does not exceed the design maximum length. It requires correct brackets and terminal position inline with MI's and regs."
Answered on 29th Dec 2025 - Member since Dec 2024 - report
"Hello

No. it can be on internal wall to longest its safe to carry weight for boiler. you need to choose a place and then plumbing need to be replaced to where you thinking to place boiler."
Answered on 26th Dec 2025 - Member since Dec 2025 - report
"The most simple answer to that question is no it doesn't, but the flue has to exit the property so the further away you have the boiler from an external wall the more the boiler install will cost in parts. Also if any boxing is required around the flue access panels will also have to be installed which will also add to the cost."
Answered on 27th Dec 2025 - Member since Aug 2023 - report
"No is the easy answer. However the job does become more complex and expensive if it's installed on an internal wall."
Answered on 27th Dec 2025 - Member since Dec 2025 - report
"Boilers can be relocated in any room as long as they are protected against water or humidity as these can cause issues with the electrics internally
What you need to consider is where your gas supply is coming into the house as this is the hardest pipe to get to the Boiler
Also, if it's a a way to convincing Boiler, which it will be where the condense pipework will run into the waste
Do you have the pipes for hot and cold supplies? Are relatively simple
And again, the flow and return pipes for the Central be round from any direction"
Answered on 28th Dec 2025 - Member since May 2018 - report
"Preferably, but not compulsory.

Some boiler flues can be installed through roofs."
Answered on 24th Dec 2025 - Member since May 2017 - report
"Not necessarily but to keep costs to a minimum the location off an outside wall is always the best location. The flue can go directly out and also the condensation water . The boiler also needs a pressure relief pipe to go outside"
Answered on 24th Dec 2025 - Member since Feb 2025 - report
"Can go on any wall - a lot are in cupboards upstairs just needs the flue to go through the ceiling into attic space and out the roof

Just costly to move the boiler and worth doing if wanted with a boiler replacement"
Answered on 24th Dec 2025 - Member since Jun 2024 - report
"No can use a vertical flue kit and exit out of a roof"
Answered on 24th Dec 2025 - Member since Nov 2018 - report
"No it doesn’t, as long as it is secure, you can buy flue extensions, but they are limited by the boilers KW rating"
Answered on 24th Dec 2025 - Member since May 2025 - report
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