Radiator valve broken off, WTF?!

[LeakyRad]

As far as I know, nobody knocked it or anything. It just… fell off. Found the knob bit lying on the floor. Looks like the plastic has perished?

The radiator still works, although obviously I can’t control the temp.

What do I do?

Quite common. We have gradually had to replace most of ours fir same reason, the heat corrodes the plastic.. It is a very quick job for a plumber to replace the trv.

A few of ours have done that over the years, it's the heat deteriorating the plastic, you could just get a new one from Screwfix or plumbing shop, that is what we have done in the past

Looks like the trv head has been snapped off.

I guess those white bits of plastic are the snapped off bits from the head.

The trv controls by pushing that raised tab up and down to control the flow and therefore the temperature. If the head snaps off it will go fully up - I think that means the value will be fully open so the radiator will be at max temp all the time in the current position with the head snapped off (it may be the other way around) ?

I think all the heads have standard fittings, so it may be possible to purchase a new head and valve and replace the head only but you's have to clean up the old one first, remove some of the crud etc and make sure you buy a head with the right diameter fitting.

I would probably replace the entire valve as to put it politely the one you have looks like it has seen some action.

Thanks all! Yes I think the radiator is full on, feels very hot. Looks like I’ll have to find a plumber 😭

If you can find a maker's name on one of the others (usually a house will have them all the same) or photograph it for identification, you can change the thermostatic head for a new one.

The valve is made in two parts, the thermostatic head is attached to the plumbing half with a nut or knurled ring that screws on. If you buy a new one you can practice taking apart and refitting, it is easier if you turn the head up to its highest position to reduce pressure on the spring.

It is worth knowing that although you can often buy a replacement head as a spare part, if the valve is still on the market, it is usually cheaper to buy a new one complete, and unscrew the head from it. You can keep the other half in case you have one jam or wear out.

The best time to do renovations to a heating system is in the summer, when it's not being used. If your valves are all old, you could drain the system (once) and change them all in one go. It would probably take about a day, and you could give it a chemical clean before draining. An experienced plumber can do it, or you can DIY. You do not need a gas engineer because it is not a gas part.

Changing the head is a 5 minute DIY job if you can identify it. No water will come out.

P.s.

If you want to reduce the heat of the radiator in the meantime, you can adjust it at the other end. Please post a photo of the other valve, from the side and above.

Thanks @PigletJohn <fangirling> 🤩 I’ll try and find a brand name on the valve. We are DIY dunces so to avoid disaster I think it will have to be a plumber.

Pah!

If you can find the exact same replacement the top part just screws on no plumbing involved
look on YouTube
I did mine think it was about £8
www.google.com/search?q=replacing+radiator+valve+top+mount&sca_esv=598c226b643eedfc&hl=en&udm=7&biw=390&bih=663&ei=EPp7Z8a3HvydhbIP0eXX2A4&oq=replacing+radiator+valve+top&gs_lp=Ehltb2JpbGUtZ3dzLW1vZGVsZXNzLXZpZGVvIhxyZXBsYWNpbmcgcmFkaWF0b3IgdmFsdmUgdG9wKgIIADIFECEYoAEyBRAhGKABMgQQIRgVMgUQIRifBTIFECEYnwUyCBAAGIAEGKIEMgUQABjvBTIIEAAYgAQYogRI4SJQ1AtYnRNwAHgAkAEBmAFkoAHzA6oBAzUuMbgBAcgBAPgBAZgCBaACxwPCAg0QABiABBiwAxhDGIoFwgIIEAAYgAQYsAPCAgcQABiwAxgewgIJEAAYsAMYBRgewgIFEAAYgATCAgsQABiABBiRAhiKBcICBhAAGBYYHpgDAIgGAZAGCJIHAzMuMqAHiSU&sclient=mobile-gws-modeless-video#fpstate=ive&vld=cid:b9af9fdb,vid:qkN700ijZ5Q,st:0

OK I feel a bit brave thanks to @PigletJohn and @rwalker

The writing was almost completely faded on the valve and it is the only one of its kind in the house! Almost all the others look newer... Anyway, after a lot of squinting and Googling, I found it - it's a Drayton TRV4.

I'll order a replacement and have a go next weekend!

As the other two say, could be an easy job that a plumber could charge £££ for.

That big silver ring, does it have a screw thread on the outside of it ? It is not possible to see from your photo.

If it does this is normally how the TRV head is held on (its not clear how yours was originally).

You can get I decorators cap from amazon that can screw on in place of the head for £4 from amazon, beating the last cost by £4 :).

That should allow you to control the temp manually. Or like piglet john said just control it from the other end.

TRV4 is a very good valve, for many years I would say it was the best on the market (and highly priced)

I see you can get a replacement head for £20. To my surprise it is cheaper than a whole new valve. It must be a popular part sold in great numbers.

You can see the knurled retaining ring in the illustration.

https://www.screwfix.com/c/heating-plumbing/thermostatic-radiator-valves/cat831012?brand=drayton&modelname=trv4&cmsp=managedredirect--plumbing-_-draytontrv4

Right, I’m ordering it today!
Attached is a photo from another angle which shows the ring, looks identical to the Screwfix photo.

FYI the other end has the little cap as described by @GasPanic, I know under out there will be the flat pin that can be controlled with pliers. Given the current cold weather, I don’t really mind the radiator being on high for now.

Pic

https://www.screwfix.com/p/drayton-trv4-white-chrome-trv4-sensing-head/7109r

@PigletJohn that's the exact one we were advised to get by our boiler man. No need to get a professional in (and despite my MN name I’m definitely not in that league!)

To be honest I am not sure it will fit.

Because that second photo does not show a screw thread round the outside.

If I had to guess ...

Someone has araldited a TRV head onto the pin without using the screw in collar.

That is what that brown stuff is around in between the white plastic bits on the valve head. I am not sure what the proper way is to fit a head to that fitting.

Someone else may know more...

The old knurled ring is still in position from the broken head. I think that when it is unscrewed, the ring on the new head will screw on.

OK got you.

Shifting that ring may be an issue though given the state of that valve ...

I know it's not done to jump on someone else's thread but the valve bit snapped off our rad when I put it back after the wall was replastered, is there a way to still use the radiator?!

I can't see what make it is. Look at and photograph some others to see if it can be identified.

I can't see a metal pin or spindle sticking out of yours.

Yes sadly the spindle has broken off so I assume I need a new valve but does that mean draining the system..?

Look at and photograph some others to see if it can be identified.

It'll probably be the hottest it's ever been without the valve although it could affect heat getting to other rads ( something to do with the flow but I'm not a plumber) 🤣

Forgot to update - last week I successfully replaced the valve head and all seems to be working fine!