Help with bleeding a radiator

[Hobbes8]

I moved into a new house just before Christmas and can't get all the radiators to work. I'm hopeful that they just need bleeding, so I've just been out to buy a bleed key, but I can't get it to turn the valve - the key turns but it isn't catching the valve at all.

The radiators are Giacomini make. The bleed valve is on the top right hand corner, at the back facing the wall. This makes it hard to see and also hard to get any other tools into the gap.

Any ideas? Do I need a smaller key? I thought they were standard sizes but I'm a bit ignorant of these things to be honest.

My radiators have always had standard valves but it may be worth going to a plumbers merchants to find out if there is something odd about Giacomini and whether it needs a special key.

Can you tilt a compact mirror behind the valve so you can get a better look, may also need a torch for more light? Some read fixings need a hex key (think male part) rather than a socket type key (female part). Is it possible this is what you've got.

cheep enough on Amazon if this could solve it.

Read = rear. Should read 'some rear bleed valves'

Thanks both - it's definitely a socket key, but the key I got (a standard one in B&Q) seems to be too big or slightly the wrong shape. I'll try a different hardware store and see what they suggest. I'm trying to avoid calling a plumber as I'm sure it's something simple. The other radiators work fine apart from these two, but unfortunately one of them is in my son's room, so we need to get it warm and get him out of our bed!

you think they need bleeding. Are they hot at the bottom and cold at the top? that is typical of a radiator that needs bleeding.

what sort of valves do they have?

are the radiators in some rooms hot? If so, turn off the hot ones. Do the cold ones now heat up?

how old do you think the radiators are? how old the boiler? does the boiler have a pressure gauge on the front, possibly behind a flap?

if you have a brass key, there is a faint chance that a stamped steel key (which is thinner) may fit. Otherwise the nipples may be have been damaged or worn by previous clumsy handling. Look to see if there appears to be a hexagonal nut round the bleed nipple.

Ooh lots of questions I don't know the answers to! I'll try and answer best I can:

One radiator is hot at the bottom and cold at the top - I think it definitely needs bleeding
One is cold but the pipes to and from it are hot. I presume it is just switched off, but the plastic knob is just turning and not connecting with the metal screw underneath. I was planning in removing the knob and turning the screw with a screwdriver, but as we have a gas fire in that room it's not urgent
The last one, in my sons room, is cold and the pipes are cold. So if it does need bleeding there is an awful lot of air. I think there might be a bigger problem, but I wanted to try bleeding it first in case that's all it is.

The radiators and boilers aren't modern and it's not a combi boiler (which is what I'm used to) but one with a separate hot water tank and immersion booster. There's no pressure valve that I can see.

There is a hexagonal nut around the bleed valve. I think the corners of the valve may be worn down a little, hence the key won't fit. I'll try and turn some of the working radiators off and see what happens.

Thanks for your help - any other ideas gratefully received!

Success! After much googling, including some earlier PigletJohn threads on here, I've managed to unstick the TRV pin. It was a slightly more sophisticated fix than hitting it with a hammer, although not by much.

Thanks all!

As for your worn nipples, it is possible to change them for new.

Due to the delicacy of modern plumbers, they seem to be called radiator plugs now and not bleeding nipples.

Some old ones do not have a hexagonal nut as shown here, the pin is recessed in a square socket and needs a radiator wrench or key as mentioned by MisForMumNotMaid to get them out. It often requires enormous strength as the old ones may be rusted in place, so you may prefer to get a plumber in, during summer.

Your open-vented system is quite easy to look after and a lot of jobs (excluding the boiler) can be DIY or plumber as they are not gas work.

It would very likely benefit from a DIY chemical clean which is very easy if you are handy and may save you hundreds on a powerflush if neglected.