random flow and return connections

[scrambler]

Going thru my central heating system and it seem that the rads have been randomly connected to the flow and return ring..

Actually 2 rads i will definitely reconnect becos they are in series!!

I guess ideally I should have all the control valves connected to flow.. but does it make a massive difference?

 

[Doggit]

If you have TRVs, then the old ones need fitting to the flow (there should be an arrow denoting the flow direction on the TRV) but modern ones can go either end. If you have modern CH system, then there will be a separate flow and return pipe to each rad, so it doesn't matter which end is which. I have never seen one of the original series system where by it was a single pipe that went from rad to rad, and the water got colder as it entered each rad, so I doubt if you have one of these. I doubt if anything really needs changing round.