The boiler is overheating in hot water mode it measures 72'c in the heat pocket but at the top of the boiler is over 100'c and when changes to central heating runs along copper pipe that is in most of the house. Somebody has put plastic pipe and it is melting and exploding out of it

james, March 2010

The HE is fitted with a Grundfoss Twin Head Pump, One Head provides Hot Water circulation thought the thermal store, the other Central Heating, The Hotwater Pump may not be working, or if it is there are plastic non-return valves in each of the pump outlets, the Heating one may be letting by, which is cauling reverse circulation and overheating of the primary boiler,

www.elanar.co.uk, March 2010