by htg engineer »
Fri Jul 31, 2009 6:21 pm
Most modern TRV's are bi-directional, so it doesn't matter if they're on the flow or return. As the TRV head senses the room temperature, not the water temperature - it really doesn't matter, all it does is closes the valve on one side of the radiator - meaning the water stops flowing through the radiator. The only considerations when installing a TRV are, don't install in a room containing a room stat, if you do make sure it's on full and use the room thermostat to adjust the temperature and the TRV should be on the end of the radiator (either end, flow or return) that has the most free airflow, and wont be hidden behind curtains etc.
The flow will be the pipe that gets hot first.
'The plumber took the feed from another radiator' that's more than likely the problem, he should tee into the main flow (22mm) and return from the boiler, not the branch feeding another radiator (one will be starving the other)
htg