changing rads and valves

[malc]

please could someone remind me of the routine for changing a rad and valves without draining the system.i`ve read it on here before and it involves blanking off the vent,as part of the procedure. thanks a lot.

 

[doitmyself]

I assume you have an open vented system with a Feed and Expansion tank in the loft.

Turn heating off and allow to cool

You need to bung up the feed pipe from the F/E tank and the vent pipe which hangs over the tank.

You can but Drain Easy kits from B&Q etc ( two bungs and a rad bleed key).

If you have an air vent on the feed pipe to the HW cylinder, this should be closed.

Open the bleed valve on the rad you want to remove and collect the water which comes out. It will stop after a short time as a vacuum will have been set up in the pipes. Shut off the bled valve.

Shut both rad valves. (make a note of the number of turns on the lockshield valve)

Disconnect the rad from one valve and drain rad into bucket etc. You can use the bleed screw to adjust the flow rate.

Remove rad.

Change one valve - make sure new valve is closed when you replace it.
Change second valve - ditto.
Replace rad
Undo valves. (undo LS valve the correct number of turns)
Remove bungs from tank pipes
Open air vent
Bleed rad.

Turn heating on.

 

[malc]

excellent instructions thanks a lot, thats a great help.