cold rad with trv

[martin123]

Hi, Ive replaced all the pipe drops to my downstairs rads and after flushing and refilling system the rad furthest away from the boiler doesnt heat up.A plumber told me to remove the trv and make sure the pin is moving freely, but it has no pin.Just a rubber plunger, if i hold down the inside of the valve with a screwdriver the rad only gets luke warm.

Ive drained and refilled a couple of times and bleed all the rads over a week but still the same problem.Ive replaced the trv head with one i know works.

Ive had a search but could'nt find anything, do i need a new trv?

Thanks

 

[breezer]

i am not a plumber or heating engineer, but if you have changed its head surley it must be something else. have you been able to bleed the offending rad?

 

[martin123]

As soon as i open the bleed valve water comes out on all downsatairs rads, i only had to bleed the upstairs

And another thing, if i turn off a rad nearer the boiler and set the pump speed to its fastest setting it gets luke warm.

 

[cookie5]

i had the same trouble when i fitted a new rad.when you bled the rads the water can be coming from the return pipe and not from the flow pipe which brings the hot water from the bolier.suggestion, close both rad valves to the rad, take rad of wall and empty it,with bucket or bowl hold under rad valve with the trv on ,this should be the flow, turn on the heating and wait for the other rads to get warm/hot.now open up the rad valve with the trv on on wait for hot water to come out.when it does close this valve of replace the rad back on the wall,connect both valves but only open trv(flow) valve until rad get hot, then open other valve (return).this worked for me.dont forget to bled after wards.
barry.