How easy is it to put thermostats on radiators?
I am finding it impossible to find a plumber to do the work.... and my gas central heating radiators don't have thermostats. Where thermostats would go the screws seem to be permanently locked on OPEN/FULL meaning that some rooms (downstairs loo, bedrooms)
Yes you will have to drain the system, or at lest part drain.
To fit a thermostatic radiator valve you will have to remove the lock shield valve from the flow end of the radiator and replace it with the new valve. You cant do this with water in