Posted By Peter Taylor14 The HSE guidance booklet THE CONTROL OF LEGIONELLA BACTERIA IN WATER SYSTEMS gives all the info you need

Posted By Jeff Watt JJF Chartered Institute of building services engineers (CIBSE) have a good Technical Memoranda on legionella and how to check your water sysyem. I think it is titled "legionairres disease" and was published in 2002. I have an old photocopy, sorry about the sketchy info. The guide goes into greater detail than this but basically says that your cold tap should be below 20 degrees celcius after letting it run for 2minutes. This should keep legionella at a low risk of multiplication. Your warm tank should be able to maintain a temperature of at least 55degrees celcius at all your warm taps. Storage tanks should be clean have a lid to prevent vermin/debris entering the water and in some cases insulated to prevent heat transfer. I would read this first before getting into an expensive disinfection routine which would have it's own risks re COSHH. All the best Jeff

Posted By JJF Thanks for that Jeff.