replacing a radiator valve Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[macthebike]

Hi, I have a leaking valve in an upstairs room, on a combi boiler system.
Is there a way of replacing the valve without draining the whole system ? And is draining a combi system the same as for a conventional one?
Thanks

[Steve the gas]

Hi,

Before you go drastic, what valve is leaking and where from?

[htg engineer]

Where is it leaking from ?

You'll have to drain the system to change the valve, but pressurised systems are easily drained and refilled - no problems with airlocks like older systems.

You could freeze the pipes to change the valve but i'd rather drain the system.


htg

[macthebike]

Hi Steve,
It`s a radiator wheelhead valve. Thanks for replying.

[Steve the gas]

If it's leaking from the nut/olive connection to the downpipe - have you tried tightening it up?

[macthebike]

[quote="Steve the gas"]If it's leaking from the nut/olive connection to

Hi Steve, It`s a leak from just below the projecting bit that turns when you screw the cap. There are two hexagonal nuts below this and the water seems to come from the top one. Should I tighten the lower one and then the top one to see if this cures it ? Or maybe lock the top one against the bottom one (2 spanner job) ?.......Thanks for help so far.

[Steve the gas]

Yes, try as you describe.

[macthebike]

Hi Steve,
I tightened the nuts....it still leaks . So is it a full draindown situation ? It is a Glow Worm Compact, which I believe has to be done with care. Any tips ? Cheers

[Steve the gas]

If you have the manual follow it.
If not,isolate boiler from power and water, find a suitable drain cock (lowest point), attach hose to outside,open drain cock.FIT NEW VALVE.
After draining,close drain cock, open filling loop , while another body bleeds rads, keep refilling up to 1 - 1.4 bar. Voila!

HTH

[macthebike]

Thanks, Steve.
In the end I solved it by removing gland nut and windind PTFE under it.
Cheers, Mac