Hi,

If you push the pin on a TRV does it start or stop the flow? I'm
wondering whether the radiator is on or off when you take off the top
of a TRV.

I'm about to remove a radiator without draining the system; I'm hoping
to isolate the radiator at the TRV and lock shield. I'm wondering what
will happen if I take off the top of the TRV. Of course, I might leave
the top on and turn it to the frost setting.

TIA