Hidden Boiler Flues

Some properties, mainly flats and apartments, have been built with boiler flues which cannot be inspected because they are hidden behind walls or ceilings. These flues are connected to room-sealed fan assisted boilers and take fumes away from the boiler.

Gas Safe registered engineers need to be able to see the flue as part of essential safety checks whenever the boiler is worked on. A flue in poor condition, combined with a boiler that is not working properly, could put those living there in danger from carbon monoxide poisoning, which can cause death or serious injury.

Some properties, mainly flats and apartments, have been built with boiler flues which cannot be inspected because they are hidden behind walls or ceilings. These flues are connected to room-sealed fan assisted boilers and take fumes away from the boiler.

Gas Safe registered engineers need to be able to see the flue as part of essential safety checks whenever the boiler is worked on. A flue in poor condition, combined with a boiler that is not working properly, could put those living there in danger from carbon monoxide poisoning, which can cause death or serious injury.

If the boiler is situated on an outside wall, it is unlikely to have this type of flue. Alternatively, if the engineer can see all of the flue, there is no need to take any further action in relation to this matter.

If however all, or part of, the flue cannot be seen, the landlord will need to arrange for inspection hatches to be fitted. This does not mean that the flue system is suddenly unsafe. As long as the boiler passes a series of safety checks − including having audible carbon monoxide alarms fitted − it can be used normally for the time being.

Carbon monoxide alarms are not an alternative to being able to see the flue and you will still need to have inspection hatches fitted. You had until 31 December 2012 for this work to be completed. From 1 January 2013, any Gas Safe registered engineer will turn the boiler off and formally advise you not to use it until inspection hatches have been fitted in appropriate places.

Although most of the affected boiler and flue systems are relatively new (installed since 2000), the risk of faults leading to the release of carbon monoxide increases as the system gets older, especially if it is not serviced regularly. It is important that you have your gas appliances serviced annually.

If your property is less than two years old then contact your builder. If your property is between two and ten years old contact your home warranty provider, as you may be covered by them if there are defects in the flue. A list of the main home warranty providers is shown below. If your property is 10 years or older you should contact a Gas Safe registered engineer.

It is the responsibility of the landlord to ensure that inspection hatches are installed and that the boiler and flue are checked every year.