worn air-bleed valves on radiator

[marcw]

After draining my central heating system to repair a radiator inlet pipe. There is now air in some of the radiators. However, the air-bleed valves are rounded on 4 of my radiators! (they are the ones on the back, making it more awkward). I have tried using a new key and also wedging some paper in there, but to no avail.
1. Has anyone got a good idea?
2. Is it OK to keep the system on with air in it?
3. What about using a self-tapping screw to create an additional bleed point? Will this leak?

Thanks very much for you help in advance.

 

[brumylad]

that worn bleed valve screw will usually come out completely. try a pair of long nose electrical pliers to grasp it.

Try to obtain a new one from your local friendly plumbers merchant.

 

[marcw]

Thanks I'll give that a try and you know if I'm successful.

 

[PEDANTICVINDICTIVEMAN]

Where do you find these "friendly" plumbers merchants then, same row of shops which sell rocking horse muck.

 

[ChrisR]

I bet if they're in the back they'll be Barlo rads with the valves welded in. You will have access problems too. The only way I know which will work for sure on those is a dremel type drill with an abrasive slitting disc in it. Make a slot and use a screwdriver.

It should be possible to use extracting tools - a left hand drill etc. I have a tiny pair of US "Mole" type grips with angled narrow jaws which usually work, but I don't know where you can buy those!

The self tapper idea might work - or a proper tapped hole with a machine screw in it. You could seal the thread with ptfe probably.

 

[marcw]

The hole is on the back, so it is difficult to get a pair of pliers in there.
I suppose it's better to take the rad off the wall to get access and replace the valve; rather than buy a new one.

 

[PEDANTICVINDICTIVEMAN]

Get a new proper rad with a 1/2" tappings which can be replaced and stop being tight fisted.

 

[marcw]

but then I'll have to redo all the fittings as well (unless new rad is exactly the same size). and attach it to the wall etc.
AND it's hard to buy something if you haven't got cash for it pal, not everyone has spare money for such things (i'd rather buy food, for example)

 

[kevplumb]

so be well fed and freeze

 

[marcw]

Thanks. Obviously I will feed myself and my family before fixing a radiator. Anyone got something useful to suggest?

 

[ChrisR]

Yes you'll obviously have to move the rad if the vent is next to the wall! If it lifts (taking the pipes with it) enough to be free of its mounting brackets, undo the unions a turn and pivot it down.
Then nip the unions up enough to not leak.

Otherwise, close the valves and take the radiator off the wall. As I said I doubt you'll be able to remove the valve female bit.

 

[croydoncorgi]

Hang on....
DON'T, whatever else you do, try to make additional bleedpoints. They will inevitably leak!

Remember also that if the gas in the rads that need bleeding is REALLY air (it might hydrogen - different sort of problem), it will gradually find its way to the high point of the system, or out of the open vent, if you have one. On a sealed system, the place where the air eventually ends up is determined by a complicated calculation involving static head (height from a given point up to the top of the system) pump pressure and temperature actually achieved in each rad (air is more soluble in warm water than in cold).

Generally speaking, UNLESS there is more air getting in, air in downstairs radiators will eventually disperse by itself.

So if all the rads with broken bleedscrews are downstairs - just wait a while. The problem may solve itself.

 

[marcw]

Thanks guys. All the radiators are on one level-it is a bungalow! I thought that the air may work its way around to the radiators that I can bleed eventually. I will have a mess with the pliers when I have some more time.

 

[brumylad]

One day soon, with the building regs insisting on x feet of insulation enveloping our homes plus all our electrical gadgets buzzing away, we may no longer need dedicated heating appliances.

If we move on to condensing patio heaters we might not even require a mains water supply.

 

[marcw]

Drink: Yes
Smoke: No
New car: No
Satellite: Yes (But I don't subscribe, so no)
Broadband: No
Holdiays abroad: not for 3 years
PC: Yes (Old, donated to me)
Widescreen TV: No
Mobile: Yes (pay as you go, 4 years old £10 every 3 months)

I will eventually replace the rads, when cash flow a bit better