Hi, My boiler has been cycling on and off for a while now on both the heating and hot water. I have changed the venturi and test point that feed the pressure switch and it has not really improved (may actually be worse!). I think the pipes to the switch have a good seal and the boiler actually runs fine with the front casing removed. Does this point to a pressure switch problem? or should I check the flue.

Tony, March 2006

clean or replace your plastic flue ventury and tubes, also if still same problem remove the round flue restrictor from inside flue adaptor. that would sort the problem out.

www.universalheatingltd.com, January 2009

check to see if flue is blocked first both sides if all ok the pressure switch is done

wolf heat, October 2007