Hi all, In these difficult times, we aren’t able to get a plumber to the house, so hoping for a DIY solution. We’ve been having problems with our central heating and hot water recently. No heat from radiators, and the hot water gets lukewarm at very best. I think we have a pumped(or gravity fed), open vented system with feed and expansion tanks in loft. This is run by our back boiler behind fireplace on ground floor. In the airing cupboard on 1st floor, we have a cylinder tank for hot water storage. With this is the water pump a 3-way motorised valve and an electric box(Honeywell). The boiler is firing and we have a warm gas fire going as normal on the ground floor. On the first floor the controller electrics appear to work, as when we turn controller switch on to either central heating or hot water, the pump in airing cupboard starts. This does heat up the feed pipe to the cylinder tank or the feed pipe to the radiators (B or A pipes from 3-way valve). The cylinder and radiators are not even getting warm and the cylinder out flow pipe is staying stone cold. The pump does get quite hot to touch and only starts up on two of its settings, medium and high(2 & 3). There’s no unusual noises anywhere, the water from cold and hot taps are flowing out as normal (just not hot!). We’ve tried a few things... Bleeding radiators (maybe not for long enough?) Increasing the thermostat on controller to 30 degrees Increasing the thermostat under the fire/boiler from 3 to 5. Opening the 3-way valve with the manual latch on the motor Bleeding the pump and turning the screw inside (appears to be turning) Checking the loft tanks. Both are full but the header tank is quite dirty. Any help or guidance would be greatly appreciated, Thanks in advance!