The Health and Safety Executive has issued a warning to builders, developers, property owners and occupiers of a poisoning risk associated with flues for gas boilers. The warning means housebuilders must carry out extensive checks on new and existing properties to find out how well flues have been installed. Some of these properties may require remedial works. The HSE has advised those housebuilders which have to check a high number of properties that a sample method may be used to assess the situation.<br><br>Properties yet to be sold or being built may also require work to ensure the safety of the systems, and those on the drawing board potentially redesigned. Key to the checks will be the need to establish whether access is available to check the route of the flue through ceilings and into roofs. This is required under CORGI technical standards published in June 2007. The HSE says the problem is most likely to affect boilers built in multi-storey flats since 2000. A spokesman for the Home Builders Federation said: “We have been co-operating fully with the HSE to enable them to ascertain the exact problem with these type of heating systems and its implications for all buildings. We …