Does a boiler have to be on an external wall?

There isn’t any definite place that your boiler should be positioned in; every house is different. There are, however, a set of building regulations and gas regulations that your suitably qualified heating engineer must adhere to when installing your boiler, and these will determine where your appliance can be located.

All new or replacement gas boilers must now be condensing in order to conform to regulations that were established in 2005. Unlike a non-condensing gas boiler, a condensing boiler has one main heat exchanger built into it. The second exchanger uses heat that’s present in the flue gasses to reheat the water, making gas condensing boilers over 90 percent efficient. During this process, the temperature of the flue gas reduces significantly, which creates condensation. This condensation must be drained and therefore your boiler will need to be located near a drainage system or have a condensate pump which will allow the boiler to be fitted further away from the drain. This is why most boilers are located in kitchens, utility rooms and bathrooms.

The boiler will need to have at least 60 cm of space in front of it to allow for a suitably qualified heating engineer to gain access for maintenance and servicing. If the boiler is located in a cupboard, it may need sufficient ventilation and the cupboard must meet the necessary fire standards. If you’re unsure on either of these points, you should ask your engineer for advice.

The flue position is one of the most important regulations that must be adhered to. These regulations are in place to keep you and your family safe from the harmful waste gases that a boiler can produce if it is not operating correctly.

The flue needs to be a certain distance from any openable doors or windows or from any air vents. This distance is usually between 30 and 60 cm, but this may vary depending on the type of boiler you have. The flue should also be around 30 to 60 cm away from any drains, gutters or soil pipes. This is because the flue gases are quite hot and can melt any plastic fixtures that are situated close to where the flue exits your home.

If the boiler is being installed in a garage, shed or other outbuilding, there are additional technologies that may need to be considered, such as a frost thermostat. Outbuildings aren’t usually heated and can therefore get very cold in winter. To prevent the pipes from freezing, a frost thermostat should be installed to regulate the temperature of the pipes.

Finally, if you want the boiler to be positioned in the loft, the space will need to be prepared so that it is safe for the boiler to be relocated. The loft will need to be boarded out so that you are able to walk in it. There should be easy access to the loft, via a ladder, and adequate lighting. This is so that any maintenance and service work can be carried out safely. Before you move it, consider that your hot water may take longer to reach the taps. The further your boiler is from the kitchen or bathroom, the longer this will take, meaning you could be wasting water and energy.

You will need to think about the position of your boiler carefully, as there are lots of considerations to bear in mind. If you want to move it into your bedroom, you may find that the noise keeps you awake in the night, so be sure to choose somewhere practical but easily accessible. 

Though it might cost you more, it is still possible to have the appliance installed on an internal wall if you wish. However, the wall must be able to hold the weight of the boiler. If it doesn’t meet the necessary standards, the wall may need to be strengthened or you may need to consider a new position. 

Moving your boiler is certainly an option if you’re unhappy with its current position. However, there are some further things that you may also need to think about before you make the move.

It’s not just the boiler that needs to be relocated, but the pipework too. Carpets, flooring or floorboards may need to come up so that the pipes can be accessed, which can turn the job into a messier and more costly one than you first thought.

A new flue may need to be installed and a hole will need to be drilled for this. The hole will be at least five inches in diameter, which could produce quite a lot of dust, so be prepared for the additional cleaning.

Finally, condensing boilers require a waste pipe through which the condensed liquid can drain away. This is why boilers are typically found in rooms that already have drainage, such as kitchens, utility rooms and bathrooms. So if you’re planning to move your boiler and there is no accessible drainage in the new location, new drains will need to be installed. This could increase the cost and complexity of the project.

If you want to move your boiler, you should think about the new position carefully and consider whether it’s worth moving it.