Best Isolating valves for Central Heating Pumps??

Have you tried heating the nut with a blowtorch for a bit? - a few heating cycles can help break the bond. You could also just cut of a short section of copper pipe either side and replace the isolating valves at the same time.

Failing that you could split the nut off - nut splitter or a metal cutting disc in a dremmel type tool.

Not bad - if you get ones that do not restrict the flow rate (and hence introduce extra water hammer noise).

I've used lever ball valves and found them fine over a 3 year period so far.

Certainly they are better than gate valves.

.andy

To email, substitute .nospam with .gl

Yes. I've had no problem with the pump, but have had to drain the system down twice to fix the gate valves, which are only there in the first place so you don't have to drain the system down. Seems to be a logic fault there somewhere?

Exactly.

I've found the red wheeled ones to be bad enough - they stick and are difficult to move when it's necessary to turn them off, and even when closed they seep or even drip quite fast.

The ones that are built into pump unions are even worse, and I've found that they can be very hard to move. You don't really want to have to mess around with WD40 etc. and leave to soak when a pump needs to be changed.

Ergo, last time, I put unions with compression fittings next to the pump and then lever ball valves next to them.

Completely effective.

.andy

To email, substitute .nospam with .gl

The 'magic' technique uses a large lump hammer as an anvil and your copper mallet. Put the lump hammer onto a flat of the of the ring nut but towards a corner. Whack the opposide face/corner with the copper mallet. Try both directions - to get some movement into the ring - the inertia of the pump body does half the work. The lump hammer protects the pipework.

Some penetrating oil round the ring will help. Put silcone grease on reassembly either you or someone unknown will thank you in the future.

Ed said: "Put silicone grease on reassembly either you or someone unknown will thank you in the future"

This is fantastic advice - always consider the future dismantling. Some lubrication will always help. When I moved into a new house I dismantled my taps and lubricated the mechanism and threads - they still work as smoothly as new and are easy to dismantle if I need to replace washers. Likewise - my garage door was well lubricated from new - many neighbours have had theirs replaced due to breakages. At one time everyone had an oilcan. Now they seem to be rare. Also a bit of Copperslip on the screws on the C/H boiler ensure easy dismantling for servicing.

Yup, same here, after learning the hard way that the standard pump gate valves are a curse. A curse I tell ya.

In article , John Rumm writes

This is what worked for me, though I used an electric paint stripper.

Thanx to all for your helpful comments

Regards: Frank Sweeting