Changing a radiator

[sddsddean]

I've got to change a rad as a 'carbunkle' has appeared on one face and it has started leaking. I've switched off both valves to isolate it until I can get a new one. My question is that on one end I have got a valve with a drain (like this
http://www.screwfix.com/app/sfd/cat/pro.jsp?id =12381
)
Will this drain just the radiator as I have got the rad valve switched off, or have I got to drain it the normal way by 'cracking' the main nuts? Just wondered which side of the valve the drain is on.

[BillyNoMates]

That valve will more than likely have been put there to drain the whole system - it is probably at the lowest point in the system.

Obviously with the radiator valves closed it can't drain the radiator but only the rest of the system.

I'd attach a hose, run it to a drain, open the radiator valves and drain down the whole system. Good opportunity to give it a flush and add some inhibitor.

You could crack the radiator nuts as you mention but it's slow and can be messy.

[sddsddean]

All my rads have got a drain valve on Billy, thats why I thought it would just drain the rad.

[naz_nomad]

I too would have said it's a ''whole system'' drain ... can't recall ever seeing a drain-off valve that just drains the rad ... but I'm not a plumber, just speaking from (a little) experience

[naz_nomad]

but looking at the screwfix link .. it seems to suggest it just drains the rad.

open it up and drain a ''rad full'' ... if it stops, there y'go ... if it keeps draining, it's a ''whole system'' drain-off valve.


A couple of minutes 'draining' should tell you one way or another ...


great help ain't I? ... lol

[barnet boy]

Hi,
I fitted one of these to a rad and it's for draining the whole system down. BNM is correct in saying when the rad valve is closed it cannot drain down that individual radiator.

Maybe whoever installed them had bought a job lot as these valves are more expensive than a standard rad valve.

[Hard@it]

If it was me I would shut both rad valves down and open the **** into a basin,( via a tube ). If it stops and you have to open the red vent to make it run, then it is only for the radiator ! .
The advert implies that it is for the rad only, and lets face it the valve when it is screwed down could go past the outlet.
Nothing ventured etc. !!
Cheers Hard@it

[Hard@it]

Please note that **** is actually drain valve, this changed by administrator. The 'red' valve should of course be rad valve

[Hard@it]

how did you get on?

[sddsddean]

Did it this afternoon. The valve does just drain the rad with the two end valves switched off, so it was dead easy to drain into a bowl and only about an eggcup full came out when I cracked the main nuts. Only real problem was that I had to change the valve tails and didn't know you needed a 1/2" allen key. Quick trip to Wickes sorted that and as a pair of rad valves c/w tails was only �3.99, I got new tails as well and chucked the rest of the valve away rather than muck about getting the old tails out. It's all working and Ididn't even need to nip anything up to stop any little leaks. I'm well chuffed with myself!!

[Hard@it]

Good to hear you had success. Hard@it