The hot water on this boiler is working fine but the heating is only working for a couple of minute and then knocking off. I have cleaned the system and the boiler parts but the heat exchanger when blown through with either air or water appears to be restricted. It is heating the first radiator on the system which is hot but the boiler just will not stay on long enough to maintain this. Can anyone help

linda, April 2010

same problem, did you fix it

john, November 2010

linda the best advice i would give you is have the boiler serviced by a qualified engineer.
has this boiler ever worked? how old is the boiler? are there any valves been fitted past the first rad? is it a sealed system?
you can get a service manual from the vokera site, http://www.vokera.co.uk/trade-professionals/manuals-literature/

stewart mclean, April 2010

may be a blockage like you suggest, may also be a faulty pump

Ian, April 2010