Can anyone help? I have a 20 year old Potterton Kingfisher CF50 boiler, an indirect 140 litre cylinder, 3 way valve and Grundfos pump set at No2. The radiators are hot, the domestic hot water gets hot - everything seems to work fine except that hot water is flowing into the expansion header tank and out via the cold feed at the base of the tank, this pipe is now warm. This hot water flows into the header tank irrespective of whether the programme is set for central heating or hot water, the only time it stops is when the boiler thermostat (a new one) is off or the cylinder stat or room thermostat is satisfied. The heating engineer who has been called seems mystified. The pump (fitted on the return to the boiler) was replaced 12 months ago and until very recently everything worked fine. Any help/advice would be appreciated.
LouiseW
LouiseW
