Retro-fitting balanced cold on an unvented - query

[jonesjw]

Hi all,

fairly new to G3 work as recently certified (!). Done a couple of installs from scratch, all good.

Job here is to retro-fit a balanced cold circuit from a Gledhill unvented to a recently refurbed bathroom that now has all mixers (apart obviously the toilet).

Cylinder has Reliance inlet control group with blanked balanced cold out and expansion tank out (although this is also blanked as tank is wired in lower down the cold feed)

I appreciate the balanced cold out is before the check valve in the multiple-block. But would folks here drain down or partially drain down the tank (the inlet group is level with approx 3/4 height of 210l cylinder) before unblanking and connecting new balanced cold circuit? I suppose my concern is - 'what if the check valve has failed?' It's a lot of water to mop up...

The group looks reasonable new - homeowner says replaced a couple of ears ago after original failed (v. hard water area, poorly serviced?)

I'm pretty sure this wasn't covered on the course but may have missed something.

cheers

 

[Ben-gee]

Turn the water off and drain mains through kitchen sink. Then crack the nut off the blank, you’ll soon see if the non return valve is working - it probably works fine - then just get on with it.

 

[jonesjw]

Turn the water off and drain mains through kitchen sink. Then crack the nut off the blank, you’ll soon see if the non return valve is working - it probably works fine - then just get on with it.

Thanks Bee-gee - that was my initial inclination - 'havago' & 'softly-softly'! Cheers, James