Hi there, I need to box in a boiler, however how much ventilation does it need??

The amount of ventilation required will vary depending on if your boiler has an open flue,a balanced flue or a room sealed flue.Ventilation requirements vary vastly so if i were you i would contact the boiler manufacturer and ask their advice or go on the internet and source the information.All boilers have a GC number.Gas Council number.This is a seven digit number that is displayed on the data badge on the inside casing of the boiler.This is the models exact make.With this information you can go online and source the ventilation requirements for your boiler.Older boilers will require HIGH AND LOW VENTILATION.NON CLOSEABLE AND NON FLY SCREENED WITH MINIMUM HOLE SIZES OF 5MM PER HOLE.Most people don`t realise that if a boiler overheats in a cupboard and burns a house down that ignorance might affect your house insurance.Lastly ,new condensing boilers normally don`t need ventilation requirements as they run cool BUT WILL REQUIRE AROUND 5MM ON THE SIDES AND AROUND 150 MM TOP AND BOTTOM FOR SERVICING

Always refer to the boilers mi manurfacturs instructions ,if lost then google model numbers for specs ,if old open vented type do not box in !! with out reading mi ,and consult a gas safe fitter ,

Hi consult a Gas safe engineer , also call gas safe for free advise .