biasi 24s boiler, I have replaced an airflow switch pipe, and a ch diaphragm, and bled the ch system. the boiler works fine without the cover on hw stays constantly hot but as soon as the covers go on the boiler cuts of the gas for a few seconds and re-ignites then cuts off again and so on the hw temp changes and gets and runs cool. how can i resolve this problem.

mpv, March 2010

why did you change air pressure pipe ? unless it was split,put in a new pressure switch that will sort it,its a honeywell in at mo just put same.

pheva, July 2010

if im reading you correctly you are removing the boiler case when the burner is on, which is foolish, it may have told you that the fan isnt strong enough to draw combustion air in normal mode so i would suspect the fan is failing and not operating the air pressure switch

john, March 2010