Worcester Danesmoor oil boiler venting hot water to expansion tank?
I have a Worcester Danesmoor Utility 26/32 oil fired boiler on a vented CH/HW system. When the boiler is running it vents hot water through the "heating vent" outlet pipe to the expansion tank in the roof space - causing condensation problems in the roof space. Otherwise the boiler and CH/HW system appear to be working properly. The boiler is only a few years old and has been recently serviced.
Boiler stat is working - that's been checked. As has the stat on the hot water cylinder.
Pump speed is set to low - any higher and that does cause an overflow but via the vent from the primary circuit in the hot water cylinder.
Gordon
December 2009
Sounds like the boiler thermostat isn't working - allowing the water to boil or the pump speed is too high.
John
December 2009
I can answer this question...
Worcester Danesmoor oil boiler venting hot water to expansion tank?