Please Note: This Article is 9 years old. This increases the likelihood that some or all of it's content is now outdated.

Gas Boiler Safety – We rent out a one bed apartment in a block where the combination boiler is in an alcove in the bedroom. The boiler is behind a cupboard door in the alcove and the flue vents to an outside wall. The engineer has told me that there is no need to have a carbon monoxide (CO) detector as these boilers are sealed systems. Is this right?


Only fanned flue or room sealed boilers can be fitted in bedrooms, since they are sealed and draw their air for combustion from outside. Conventional flue boilers, which draw their air from the room, must not be fitted in a bedroom.

There is general belief by many heating engineers that as these boilers are of a fully sealed type, there is no need to take additional precautions with regard to carbon monoxide (CO) detection.

However, further clarification is now available from: the Gas Safe Register, the Health and Safety Executive (HSE), the Council of Gas Detection and Environmental Monitoring (CoGDEM) and the Institution of Gas Engineers and Managers, on CO Gas Safety.

The consensus is that while a sealed type combination boiler should prevent CO leaking into a property, it does not guarantee against this. There have been a number of instances of seal failures over the last three years, some of which have resulted in fatal CO poisonings.

A combination boiler would also offer no protection against CO leakage as a result of faulty appliances or a fault developing with flues, so audible CO detectors should be fitted.

As all landlords should be aware, there is a legal requirement to have all gas appliances in rentals checked and maintained on an annual basis, and a certificate issued to the landlord by a Gas Safe registered engineer (replaces Corgi), plus a copy issued to the tenant.

There have been calls of late from experts in the industry for specialist gas analyser tests, which some engineers now do, to be included in the annual checks – not currently a requirement under the legislation.
In addition, some properties, mainly flats and apartments, where boilers are not on an outside wall, have extended boiler flues which cannot be inspected because they are hidden behind walls or ceilings.

Recent guidance means that Gas Safe registered engineers now must be able to see the whole flue as part of essential safety checks, which may mean landlords having inspection hatches fitted.

©LandlordZONE All Rights Reserved – never rely totally on these standard answers which apply primarily to England and Wales. Before taking action or not, always do your own research and/or seek professional advice with the full facts of the case and all documents to hand.

Please Note: This Article is 9 years old. This increases the likelihood that some or all of it's content is now outdated.


Please enter your comment!
Please enter your name here