I have a solid floor with live radiator pipes coming through - they both have identical standard valve heads on them and I want to put a radiator on - any easy way of telling which is flow and which is return?
Thnx for replies guys - there's currently no rad attached and valves are turned off. Not sure of pipe run as under concrete but length will be several metres of 15mm - not sure heat will reach. Bit late after attached radiator cos need to make sure I get the TRV on right side first time.
you could open one valve at a time catch the water in the bucket,time it see which heats up fastest
you can also buy trvs which can be fitted to either pipe so it wont matter which is flow or return myson i think do them