Radiator hot without thermostat head on, cold with it on?!

[Confusedjen]

Hi
Can some please help advise. We had a plumber round when I wasn’t home, bedroom radiator wasn’t working and I came home to it ‘fixed’ boiling hot but plumber had left the thermostat head off.
I tried to put it back on (had to push down to get the thread on ring and thread on other side to meet to I could twist on) and now it’s cold?!
What am I doing wrong please. I know the radiator works without the head on but I want it on so I can adjust the temperature. Must be how I’m putting it on or the head is faulty?!
Any advise please

 

[terryplumb]

Before fitting the actuator ,turn it fully clockwise then anticlockwise,and while doing so observe the internal centre spindle in its base. It should move in and out. If it doesn't it's duff. By the way , turn the actuator head to fully open ( highest number) before fitting to body.

 

[Confusedjen]

It doesn’t move in and out but the pin inside can be be pressed in on 5 and not and in place solid if on 1 so I think it should still be working?!

 

[Madrab]

As suggested, put the head back on at setting 5, so it goes on easily and then leave it. If the radiator doesn't heat up with the TRV on and set to 5 but it does when the head is off then it can only be the head to blame. The valve itself is mechanical so the pin is either pushed down and shuts off the valve or it isn't, so it either works or it doesn't.

Time to replace the head, if you can get a direct replacement - not every TRV is made equal -or replace the whole valve if not.

 

[fixitflav]

As suggested, put the head back on at setting 5, so it goes on easily and then leave it. If the radiator doesn't heat up with the TRV on and set to 5 but it does when the head is off then it can only be the head to blame. The valve itself is mechanical so the pin is either pushed down and shuts off the valve or it isn't, so it either works or it doesn't.

Time to replace the head, if you can get a direct replacement - not every TRV is made equal -or replace the whole valve if not.

Might add that if it gets hot on setting 5, turn it down to various lower settings and check the rad temperatutre changes. If it doesn't, time for a new head.
And have word with the plumber about doing half a job.

 

[Confusedjen]

Thank you everyone really helpful, it’s not my house I’m a lodger and me landlady freaks out about anything house related, think I’ll just get a new head and swap it over

 

[Madrab]

think I’ll just get a new head and swap it over

Just as a reminder, if you can't get the same make of TRV head for the same valve then it may not work, they are not all the same and have different throw distances, i.e. how far the sensor head pin moves from open to closed

 

[Confusedjen]

Hi
How many different types of heads are there? What is the likelihood of it fitting? How can I make sure I get the right one?

 

[fixitflav]

Hi
How many different types of heads are there? What is the likelihood of it fitting? How can I make sure I get the right one?

Take the current one to the shop with you. It will have the manufacturer's name on it. Try to get an identical one. If you can't, a bit more thinking required.

 

[Confusedjen]

Hi got a new Trv head and it’s still not working. Radiator is boiling and can’t be adjusted. I’ve tried two new TRV heads. If I push the pin down without a head on it goes quiet which I assume is turning it off/down. Any ideas please? Is there a problem with the I internal parts of radiator instead of the TRV head??

 

[terryplumb]

You must have the wrong actuator head ,or you are not fitting it correctly.
Show us some pics

 

[Confusedjen]

Hi, surely there is only one way to fit it? I turn it it 5/6 place on top with slight pressure and secure with the screw ring. I’ve tried two difference ones and taken old ones to tool station and screw fix and they’ve said they are the correct replacements?

 

[terryplumb]

Take the head off, show us pics of the body ( from birds eye view) and pic of the head from its underside ( so we can see the bottom ,inside of it )

 

[Confusedjen]

Here you go

 

[terryplumb]

Thanks. Hard to tell for certain but I suspect it's the wrong actuator head. The hexagonal shape( that the pin is on the centre of) atop of the valve body doesn't like it will sit fully into the actuator.
Of you close the actuator fully ( to its lowest number) and try to fit it onto the body,you should feel resistance from the spring under the pin, so it will be pushing up whilst you are trying to push the actuator downward to enable the Screw ring to engage. If you can't feel that spring pressure ,it's the wrong actuator head.
Do you have the same TRV on another radiator that you can take off and try