can't remove old satcwell TRV

[longdistancemum]

Turned on CH in 2010 and the rad in back bedroom wouldn't heat up. Tried bleeding, no air. Inlet pipe to rad also cold. Asked BGas man when came for annual check but just said needs a power flush without looking at it. As it was £400 we've left it. I mentioned it to a central heating chap working at a neighbours house and he said unlikely to need a flush to fix it if it's an upstairs rad. The boiler downstairs. To save having it flushed I'm trying to get the trv off to see if the pin is stuck but I can't get the trv off. As the pipe is also cold am I wasting my time? Is it a flush job after all?

I've got the screw ring loose and it moves up to reveal what looks like about 16 flats fingers that go all around. These seem to have an iron grip into a groove and I can't get them to let go. Am I trying to get the wrong bit off?

 

[lame plumber]

go easy, if the centre pin does free up and come out. how are you going to seal it up later when water is everywhere, get a plumber into do a change!

 

[dancinplumba]

try tapping trv with hammer gently to see if pin will free up

 

[Dotty]

Welcome to the forums!

Could be a stuck pin, could also be a balancing issue but one step at a time! What make trv is it? Danfoss? Myson? Bulldog? ............

 

[Dotty]

Not sure she's got the head off yet guys!

 

[dancinplumba]

its satchwell and we know croppie 🙂
could you put a pic up ?

 

[longdistancemum]

thanks. i'll try to figure out how to add a photo.

 

[dancinplumba]

have you tried turning other rads off to see if this rad gets hot ?

 

[longdistancemum]

sorry it's a bit fuzzy. the ring is just resting at an angle so that you can see as much of what's there as poss. I can't push it any further up because of the bit of grey metal strip in the way.

What does the fact that the inlet pipe is cold suggest? I haven't tried turning the other rads off as half the trvs are turned down to min but are working as if I want max, so won't actually turn off. Or does something other than the trv turn them off? They do look rather old so I've assumed they aren't working properly.

cheers
Thanks

 

[longdistancemum]

i have now turned all the trv down to their minimum. how long do i wait and any advice about turning them back on?

 

[stevetheplumber]

That head just pulls of now you have the ring of by the age of it it realy needs replacing id pull the head of and give the valve a few sharp taps on the side furthest from the rad as if your trying to push the valve in towards the rad dont pull on the pin it will probably pop out and leak if you must play with the pin tAp it downwards

 

[longdistancemum]

I've got one off. Not the one I wanted but one in the hall. You have to try to prise all the little claws out of the notch. Almost impossible. I only managed because I've got not-stubby finger nails, my husband wouldn't be able to do it! There must be some special tool to do it. They will NOT just PULL off. I've done a diagram for anyone interested. I've tried to get the cold rad one off now I know how but still can't manage it. It's still cold and all the other rads are now even hotter, even though the trvs have been down to min for over an hour.

Now I've got one trv off how do i deal with the green corrosion and how far up and down should the pin go? I can wiggle it up by about 2mm.

Thanks

 

[lame plumber]

not being mean or sexist but when you get the trv head off and you move the pin and it comes out leaking water what are you going to do then, call in a plumber who has A. a pipe freezer (electric not in cans) and B, a wet vac to catch any spillage. Get him to drop off and replace the trv. cost 1 hours labour, £30-40 freezer hire charge (nothings for free, but saves a drain down and refill) plus a new trv

 

[longdistancemum]

Oh no! I was ever so gentle, just gave the side of the valve a tap and the pin a tap and now it's leaking. Help!

 

[Dotty]

As pointed out what could happen, afraid you need a plumber onsite now. Whereabouts are you?

 

[lame plumber]

Did say dont touch, loads and loads of insulating tape and a baking tray

 

[Dotty]

its satchwell and we know croppie 🙂
could you put a pic up ?

Doh! Didn't read the thread title!

 

[longdistancemum]

Hi lameplumber. we must have posted at the same time as I didn't see your post. As so many forums suggest tapping it I did't expect it to leak unless I pulled it out. Wish I'd seen your post before I tapped it. Anyway what about all these hot rads that are on min??

 

[longdistancemum]

I'm in Northampton. Can you recoomend anyone if you aren't local?

Cheers

 

[lame plumber]

trvs will come on initially at low settings to bring the room/area upto temp, then they should cut off as area has warmed up, you may hear the flow of water start/stop if you tweak the valve up or down. If the rad stays hot all the time when the valve is off or on frost setting , new valve time

 

[longdistancemum]

thanks.

 

[lame plumber]

dont cover that far up and Ive lost my passport, so anyone in Northampton for a leaky lady

 

[Dotty]

Think [MENTION=2718]REDSAW[/MENTION] is out your way.

 

[doitmyself]

trvs will come on initially at low settings

No they don't.

A TRV in a cold room with the heating off will be fully open. When the heating is turned on and the room temperature rises the liquid/gas/wax in the head expands and the pin goes down so the valve closes a bit. On a properly balanced system the TRVs should not be switching between open and closed but just opening and closing a little bit to maintain the correct room temperature. A bit like the way you maintain a constant speed by using a car's accelerator.

 

[lame plumber]

Its Xmas OH YES THEY DO BEHIND YOU and she doesnt want to know now she just wants a plumber!:30: