flushing a central heating system

Why not just replace the bleeding valves?

If you do want to change radiators without altering the width of the pipework you can buy extendable radiator valves which will accomodate a slightly smaller radiator replacement.

Replace the faulty valve at the same time as draining.

Get an assistant as gopher, several bowls/trays that will fit under the pipe by the valve.

Use a small hacksaw to nick the underneath of the pipe until the water flows out but you can stop it with your finger.

Fill the bowls until the flow stops. The gopher does the emptying.

I think the OP means that the bleed screw in the top ofthe rad is stuck solid.

I'd spray the drain screw with Plusgas a few days before draining the system. I'd then (attempt) to remove the screw with a *decent* brass radiator key and a pair of molegrips, taking care to undo it the correct way.

sponix

Yes that's what I mean. I'll give it a go. The radiators are fine in all other respects and luckily (when the bleeding valve worked) there was never any air to get out of them anyway.

Thanks

Have a look at product code 6918 on

John Kelly explained :

Get hold a good quality bleed valve key. Drain the water down a few inches in the three radiators and put some heat on the bleed screw (blow lamp/hot air gun), alternated with a cold damp rag to help free it. Some bleed screws are mounted in a removable socket - remove the entire socket and replace with new.

Or DIY: a 1/2" BSP x 15mm compression Chromed coupler plus a bit of 15mm Chromed tube will allow you to make an arbitrary-size extension tail piece which looks quite decent.

Good advice - my standard grey key broke just 10 minutes ago :-(