Hi, My son had a realy old boiler although the radiators and piping was not bad. I have a Worcester combi 350 at home and I bought a good second hand one for spares so when my sons packed in I thought it would be a good idea to change to a combi system as he lives alone and I love mine. We decided to do all of the plumbing ourselves and get a corgi guy in to conect the gas and check it out. We removed the old tanks in the attic and the hw tank and blanked all of the pipes off.
when the boier was commissioned we got hot water but the central heating water did not circulate( the pipe gets hot for about 300 mm) I checked that the isolation valves were all turned on and the system bled, with no air coming out. I checked all locksheild valves and thermo rad valves. I checked that the pump was working and it was. The only thing I can think of is it possible that the pipes that took the water to the hw tank were flow in and out and therefore by blanking both off i have stopped the flow? should I then fit a loop to join these two? or any other ideas? Thank you in advance