Why do I need to move my boiler flue?

As with a large number of other building regulations, the legislation of boiler flues has gotten a lot tighter over the years. At one time you could put your boiler almost anywhere in the home, no problem, but these days there are some very strict rules an installer has to follow, which sometimes mean that the position of the boiler has to change or the flue itself altered. In this blog, we’re going to give you a run-down of some of the important points that these regulations tend to flag up on a new boiler installation.

Flue position

Depending on the size of the boiler, the flue must be positioned a certain distance from the nearest window, door, or air brick. Typically this is around 30-60cm if it’s to the side or above the opening, and a bit more if it’s below. This is because the waste generated by combustion can include dangerous gasses like carbon monoxide, so you don’t want that waste gas too close to an opening where it might re-enter the home.

There are also some less obvious regulations that affect the siting of the flue. It needs to be the same distance away from corners of a building, at least 60cm above flat roofs or balconies, well away from soil or drainpipes, and the eaves.

Temperature-sensitive building parts

The gas that comes from a flue can be hot, so as well as keeping the flue away from anyone’s skin, the flue should also be sited well away from any materials that could be adversely affected by that heat. For example, the flue should be sited at least 30cm below any plastic guttering.

Flue position and property boundary

Another constriction is the location of the proposed flue, relative to the boundary line of the property. This is going to be particularly relevant if your flue goes out directly onto the street.

If the flue is within 60cm or so of the boundary line of the property, it could have health and safety implications for anyone walking past, so would not be allowed. Generally if the flue must go out onto a wall next to a public walkway, the flue is diverted up above 2.1m to ensure the flue gasses are always above head height. Unless you’re on stilts (the guidelines don’t take this in to account though.)

Flues and rooflines

There are similar regulations regarding flues that exit at roof level. These regulations are specifically meant to help aid the movement of the flue gas. For the most part this is not relevant as almost all flues these days exit horizontally through a wall. It’s only really if you have a solid fuel burning appliance that the flue will sometimes exit via the roof.

Any flue that goes through the house for any distance will usually end up being concealed in a cabinet or boarded over. Regulations now require access panels to allow access to the flue run at regular intervals, so you may find the addition of little openable panels necessary.

If you are keeping your current boiler…

Remember, just because these regulations mean that a new boiler may have to be put somewhere different to your old boiler, it doesn’t mean that your old boiler needs to be adjusted. Most of these regulations only apply to new installations, so be very wary if someone servicing your old boiler says that it ‘no longer meets the regulations’ or that it has to be replaced because a new law has come in to effect. Chances are that they’re trying to get you to install one of their new expensive boilers, when your old one is just fine as it is.

The thing to take away here is that, unless you are getting a new boiler, there is unlikely to be any reason to adjust the siting of your current boiler. If you are thinking of getting a new boiler, just remember some of these points and bear them in mind when you are getting someone to quote – it may then be necessary to resite your boiler. Remember, get a Gas Safe installer to carry out your works, as they will have the necessary knowhow and knowledge to make sure the building regulations are adhered to and that your new boiler is completely safe.

If you’re thinking of getting a new boiler then fill out the form below to find a trusted local installer, or try our partners over at Heatable, who offer finance options starting at only £10.28 a month.

Think we missed something? Do you have a different opinion?

Comment below to get your voice heard…