Radiator flow direction? All aspects of plumbing questions and answers, help, tips and information

[3magnet]

We have removed our radiators about 5 months ago when we first moved into our house to get them sandblasted and repainted. We wish to replace one regular valve on each radiator with a thermostatic valve, but we can't remember which way is the inflow/outflow side of the radiator...How do we figure this out?

[bobplum]

what kind of system do you have

[bobplum]

have you tried turning the heating on seeing what pipes get hot this will be the flow?

[3magnet]

Hi Bob,
Thanks for the tip about turning the heat ona and feeling which pipe gets hot. We have the standard iron radiators, not the double convection (or something) type. If I fit thermal valves to them, would I still require the room thermostat and how will this influence the thermal valve?
Thanks