RADIATOR VALVE PROBLEMS-NEED TO DRAIN WHOLE SYSTEM??? All aspects of plumbing questions and answers, help, tips and information

[stevehayes]

I have tried to remove one bedroom radiator to flush it through outside in my garden. I removed the lockshield cap and tightened that nut and the water drained quickly from that side. On the thermostatic radiator valve side, water kept flowing. I turned it off but as my system is 20 years old does this still not stop the flow? Will I need to drain down my whole system to take the radiator off? I drained so much water and it was spraying everywhere and just not emptying from the radiator fully! Any help please would be very grateful!!

[htg engineer]

With most thermostatic radiator valves, you need the cap that is fitted to the valve when it is bought to isolate the thermostatic valve side of the radiator.

If you haven't got the cap - then you might have to drain the system - as some trv's only turn down as low as frost protection setting.

Hope this helps

[f1steven]

If you isolate the water supply to the central heating you will only need to drain the system a little as you are working on an upstairs radiator, make sure central heating is turned off too so it isnt pumping water through pipes as u work on it .!!! hope this helps too

[stevehayes]

thanks for your help. I think I have an older wheelhead (thermostat0 valve which won't shut off the supply so will need to drain the system. How to I shut off the central heating supply without affecting the hot water supply!!?