Flow direction

[moosehead]

Had an extension built last year so central heating system was extended. Plumber inadvertently [or just couldn't be bother to check] changed the flow of the system. Some of the rad valves are new but on the old part of the system they are not.
1) Do I need to change valves on old part from one side of the rad to the other?
2) when balancing the system presume the lock valve should be on the the return as opposed to the flow.

Would appreciate a bit of advice.
Tks

 

[kevplumb]

dont make a lot of difference you restrict the flow or return

 

[moosehead]

Thanks KP will re-check to night. Might also need a couple of new rads as I fear a bit of sludge in syst

 

[ChrisR]

Old thermostatic rad valves sometimes make a noise going backwards.