Reverse Circulation Central Heating

[James_Smith789]

Pump needs to be fitted on the part of return pipe that is last to go to boiler. Not teed off in the flow circuit of pump.
Is yours done this way?
You really should be getting the installers back to fix their work.

From what I can see it is (Upstairs) rad return, hot water return, (downstairs ) rad return, pump and then bypass/safety closest to boiler.

 

[Moffski72]

Apologies for typo...should have been 'not PIPED up right'...as in incorrect. The tee that is directly above the pump should be the tee off for the cylinder return...its not though, and this is the problem. It creates a route for the water to circulate, bypassing the heating zone valve on the rad circuit and allowing the reverse circulation effect, heating up your rads when the hot water is on. The best solution is to alter the pipework so that the cylinder connection is the last one before the pump.