Hi, I have an older central heating system with gravity hot water ideal Mexico floor standing boiler, cylinder on landing f+e in loft, I recently had cause to switch off the bathroom radiator this radiator has lock shields both sides, I turned off the right lock shield fully and the radiator went cold as expected, I chose the right lock shield as the trv's on all the other radiators are on the right so assumed ( not necessarily correctly of course) that this was the flow side, now not sure if it's relevant or not but this radiator is on all year round, even when the rest of the radiators are off by the thermostat in the hallway, the pipe on what I assumed was the return is hotter the the pipe on what I assumed was the flow, I tested my theory of the trv being the flow side by feeling the pipe on living room radiator trv side switching on the heating and it got hot first so I thought my theory stacked up, but this didn't seem to be the same on every radiator, one question is it possible that some radiators are piped flow on the right return on the left and others vice versa, I also need to work out what order the radiators are on the circuit the kitchen and Hallway drop down from the ceiling in 15mm ( concrete floors downstairs) I'm confident it's living room first in the circuit, but don't think kitchen and hallway are 2nd and 3rd, this may not be at all relevant, and I know I'm waffling big time sorry, but is there a simple way to determine for sure, which is flow and such is return if it helps at all, the right lock shield in the bathroom had to be turned a fair few times to shut it off, my understanding is if it was the return that may have only needed 1-2 turns many thanks in advance Carl