Stuck TRV

shiraz99

I've been going round all the radiators in the house to make sure they're all working ok now the heating is back on and have found two where the TRV pin is stuck, but in the open position. Has anyone any tips on how to free them up.

Also the pins on these TRVs are quite stubby and conical so I won't be able to grip them. I've tried giving the side of the valve a few sharp knocks to see if it frees the diaphragm mechanism but this hasn't done anything. Also tried WD40 and whilst there's some very slight side to side movement the pin still won't depress.

Browntoa

I tap the pin on mine with a hammer gently, normally frees it with some wd40

Sometimes need to pre clean the area with a wire brush 

BUFF

Browntoa said:

I tap the pin on mine with a hammer gently, normally frees it with some wd40

this is what I have done

Eldi_Dos

Rub the shaft of pin with a pencil to get some graphite on it then a closed set of pliers, hold the centre hinged part of plier above pin and press down with other thumb, I feel this has less chance of bending pin.
If still no success get a hairdryer and heat up valve area and try again.

morhen

covered nicely in this video here:

https://www.youtube.com/watch?v=U2CY4rHr7nA

shiraz99

morhen said:

covered nicely in this video here:

https://www.youtube.com/watch?v=U2CY4rHr7nA

Not quite. Mine is stuck in the open position.

Mutton_Geoff

shiraz99 said:

Also the pins on these TRVs are quite stubby and conical so I won't be able to grip them

They are normally thin and cylindrical. Has someone been clouting them before and rounding them off. Is there any movement in the pin at all (they don't usually travel very far, just a few mm).

shiraz99

Mutton_Geoff said:

shiraz99 said:

Also the pins on these TRVs are quite stubby and conical so I won't be able to grip them

They are normally thin and cylindrical. Has someone been clouting them before and rounding them off. Is there any movement in the pin at all (they don't usually travel very far, just a few mm).

There are different types. This is mine

Strangely I did manage to it moving a bit earlier when the heating was off and even managed to shut the rad off with the TRV but since the heating is back on it won't budge.

Rodders53

Mutton_Geoff said:

shiraz99 said:

Also the pins on these TRVs are quite stubby and conical so I won't be able to grip them

They are normally thin and cylindrical. 

Sounds like Pegler Terrier TRVs also sold under the Boss brand name... https://www.pegleryorkshire.co.uk/EN/Brands/Terrier/Terrier_3 check out the spares diagrams where the actuator is shown.

If one is stuck open it might can be forced closed by pressing hard or a short sharp tap with a hammer.  (I'd suggest graphite is better than any petroleum oil product due to the o-rings swelling if contacted by such petrol products).

NB There is minimal movement of those Pegler valve 'pins' between open and closed.

I've had one or two (maybe more) of the Pegler style TRVs in this house stick.  Also have found that the plastic 'button' in the head (that operated the button in the valve) has deformed such that it fails to close the valve.  New head (or complete valve if equally cheap) is the solution in that case.

EDIT  Cross-post with that post of a photo of a Pegler style valve.  You can try some graphite and a loosen of the brass screw - but too much and you'll lose some water.