Drayton Valves

We have Drayton thermostatic valves on our radiators and I think some have become jammed and inoperable. They are quite old, maybe 15 years or so.

Can this happen to them? As a start I have removed the top portion of one of them, exposing the little pin, and simply cannot make that move up or down. Does this mean it has become jammed up and needs replacing? Is there a way of dealing with these by perhaps spraying with WD-40 or silicone to try and free it? If they need replacing does the radiator need draining?

Any help and advice most welcome on this. Thanks. John In limine sapientiae

Reply to
John Edgar
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Have you tried hitting it? Before you actually replace the valve, it's worth (as you have nothing to loose) whacking the pin (gently at first) with a small hammer.

Reply to
Bob Mannix

They are usually very stiff. You can't just push them down with your finger. At least not without some blood. You'll need something beefier, like a hammer to loosen and a hard block to push down on to test.

However, it is quite possible that they're jammed. You do normally need to drain down to replace them, but it isn't the hardest job, especially if you get matching parts, so you only need to change the valve body and not the connectors (i.e. the rad tail and compression olive).

Christian.

Reply to
Christian McArdle

The pin should move fully "up" with the handle removed, and the valve will then be fully open and the radiator hot. However, if the rad is cold with the handle removed, that would imply your pin is fully depressed, and jammed in. That should at least tell you whether your pin is jammed in the "up" or "down" position!

They can often be freed with a bit of friendly mechanical persuasion, but be very careful you don't bend them in the slightest. However, it's likely to happen again and replacement of the valve is probably the best option.

Yes the radiator would need draining (watch out for the black sludge which will likely emerge and stain your carpets irreversibly!); but it order to change the valve you'll also need to drain the whole system (usually from a draincock located at the lowest point, unless you're unlucky). Lots of info available on this if you search the archives of this newsgroup via google.

David

Reply to
Lobster

I'll agree with the other replies, but bear in mind that at this age, the valve heads are really on borrowed time. Generally they are reckoned to last about 7 years.

So even if you do free the pins, you may find that the thermostatic function doesn't work with the flow being fully on or fully off and no actual control.

If that looks like being the situation, then frankly it's better to replace the whole valve and done with it.

Reply to
Andy Hall

In message , John Edgar writes

Here's how I free them off

Take a spanner or some such implement and lay it on top of the pin

Tap the top of the spanner and after a while it should come free.

Reply to
raden

Thanks for all the help and I am going to get them replaced. However I think the problem on this particular radiator is something else. It has a semi-circle that is cool, from bottom left to bottom right and not quite to the top. The rest is hot. Very strange and I wonder what it could be. I have opened the balancer valve 1/2 a turn with no effect. Could there be air locked into it and if so how does one remove it when it isn't actually at the bleeder hole? John In limine sapientiae

Reply to
John Edgar

If it was air, then it would be the top of the radiator which would be cold and you would be able to get rid of it by the bleeder valve. This sounds more like a pile of sludge at the bottom.

The radiator needs removing (note my comments previously about stains from the sludge!), taking outside and blasting through with a hosepipe to clean it out; in the reverse direction to the way the CH water normally flows through it.

You also need to stop the sludge from building up again (caused by corrosion inside your system, which is bad news), by adding inhibitor to the system when it's refilled.

David

Reply to
Lobster

This is caused by a radiator being plumbed with two bottom connections and at a VERY slow flow rate (inadequate pump or valves nearly completely shut, or whole system not balanced, or any combination of these) The hot water trickles up from the feed valve across the top and then down the far side being pushed by the water flowing in behind it, little mixing and inertia. Obviously cool water next to its path gets warmed a little thereby giving an approximately hemi-spherical cool patch in the middle.

Nick

Reply to
nick smith

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