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Hot water tank gone? do pipes get linked?

Postby colin9876 » Sat Sep 29, 2007 9:07 am

Boiler changed to combi.
Old system had a branch from the outflow through a coil in the tank.
Plumber just linked this to the inflow with a strip of 22mm pipe when he removed the tank.
To me this seems like a short curcuit, a low resistance short way for much of the hot water to go straight back to the boiler.
I said to the plumber wouldnt it be better just to block these (forcing all the water to go round the rads)
He said 'no then ur only return is through the rads, I like to keep things moving a bit!'???
Does his theory make sense?
The rads are still getting warm but I cant believe that in parrallel short curcuit is helping??
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Simply Build It

Postby htg engineer » Sun Sep 30, 2007 9:05 am

Once the tank has been removed to be replaced with a combi boiler, the primaries are redundant, all he would need to connect up would be the hot, cold, gas and the heating flow and return.

Did he remove the old boiler as well as the tank ?

Some people leave back boilers in, so that the gas fires can still be used and to avoid alot of mess and re-decorating. If he has done this but left the boiler connected to the heating system, then he would need to connect the primaries together. Very perculiar and not recommended

You'd be losing alot of heat, the sludge etc. built up in the old boiler, would now be circulating around the new system. And I'm assuming the old system would not have been pressurised. So the old boiler will be under alot of strain.
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