Changing Motorised Valve / Draining System

[iainbo]

Hi all,

I know it is an old topic but I'm struggling a bit. The hot water valve has siezed in the open position, I took the head off and tried to turn the the gate but only succeeded in shearing the top off the valve.

I've bought a dayton replacement valve. All other posts mention draining the central heating system, showing a drain on one of the rads - none of my rads have a drain. There is a gate valve underneath the pump which someone has labelled 'sludge', but I don't know where this pipe goes - it disappears under the hot water cylinder. I live in a ground floor flat.

I've tried turning off the supply and outlet on the header tank and then slackening off the valve I'm trying to change - I got about a bucket of water with no decrease in the pressure before giving up on this.

I think I could freeze one side of the valve, but the other side goes straight to a tee piece, with the CH valve.

Any advice would be much appreciated.

Thanks,
Iain.

 

[misterdubya]

As for Drayton, if its a spring return valve your changing, use Honeywell - much better quality.

Just drain it, (remove a rad and drain through a rad valve). Replace rad valve with one of THESE , refit rad and re-fill with inhibitor. Unless it has really limited access, you should be done in an hour of 2.

The drain off can now be used at a later date.

Mr. W.

 

[iainbo]

Thanks Mr W, will give it a go this week.

 

[kittedup]

Did you bung the open vent when you tried to slacken off the valve?

 

[iainbo]

No I didn't - I can only see one open end - returns into header tank, don't know where it comes from, appears through ceiling above header tank, is this the open vent?

Cheers, Iain.

 

[kittedup]

Yes that is the open vent.

Make sure everything is switched off. Bung the open vent and bung the cold feed. Make sure any auto air vents are closed off.

Crack open the valve nut and you'll get some water out, but it should stop. Works on the theory that no air can get in so no water comes out.

Works 9 times out of 10.

Worth a try before going to the hassle of taking a rad off.

Ted

 

[iainbo]

Thanks Ted, will try that before taking off rad.

Iain.