Cold radiator with hot supply present and a TRV pin up?

[toomuchjam]

Just moved into a new build that has sat empty got two years.

We have two radiators that have hot water supply but have never been hot. I have had both TRV valves off the radiators and both pins come up.

My only thought is that the internal gubbings of the TRV that actually do the job rather than the visual pin are broken.

I don't know how to check this, do I have to drain the whole system.

I am sure this can be sorted by me but have hit a wall.

Pretty good DIYer.

Chris

 

[BARNY78BG]

take off lockshield valves to confirm you have flow through both sides of rad

 

[Gasinayr]

Have you checked that the lockshied valve at the other end is fully open.
If open, remove the trv sensor and tap the trv body with a hammer, the valve could be stuck into the seating if the house has been empty for a while

 

[toomuchjam]

Thanks both.
The lock shield valve is open and I have given the trv valve a good tap but sadly no joy.
Forgive my ignorance but i am a little unsure. What you mean when saying to remove lock shields?
I was convinced it was not connected to hot water loop originally but I opened the drain nut on the lock shield and after a while it ran very hot, but could this be the return? The trv is not always on the feed, right.
Chris

 

[Jordon]

Turn all other trvs on other rads off, and if they don't all have trvs then turn off one side of all rads in the house and leave the one that dosent work on, if you have a cylinder turn off on programmer. So this will push out any air in the lines to the rad either in to the rad or out expansion pipe and should run hot if not the trv is prob shot or blockage in either flow or return.

 

[toomuchjam]

Thanks Jordan.
We have an unvented cylinder not quite sure what you mean in terms of turning off the cylinder, sorry!
Chris

 

[Jordon]

Just turn the hot water side off on the programmer. You can push and pull the pin out when you have done this as the pin may have pulled out of the washer jumper in the valve, don't pull to hard or you will pull it out completely and get a eyefull of h2o

 

[toomuchjam]

I tried turning off the valves and not had any obvious joy.
However I took off the lock shield end and drain the rad proving I guess we do not have a through put as the trv end was open.

However once I put rad back together for the first time the trv end pipe was hot, this is a step in the right direction! So I guess with my limited knowledge the trv valve is knackered.

How do I get this off without getting soaking!

Chris