In the summer unless I lock shield them off I get some radiators hot when only the DHW is on (all CH. Off) I think I know what my problem is, my son has read that when I installed my own CH System I should have brought the HW cylinders return out so it was the last connected returning to the boiler! So OK that’s what I have got wrong and apparently, this will cause reverse flow allowing the radiators to get hot. But I just can’t get my head around is how the water could flow to cause this with both zone valves closed!
Could someone indicate on my drawing how this could happen please?
Regards from a perplexed Richard
Could someone indicate on my drawing how this could happen please?
Regards from a perplexed Richard