Supply to unvented cylinder

[Kus]

Hi all, I currently have a 15mm mains supply to a unvented cylinder in the loft as the pipe goes under a tiled floor en suite and it was not upgraded during the installation. I am now in a position to upgrade to 22mm but do I have to use a G3 qualified plumber for renewing the 15mm to 22mm copper pipe?

 

[joni os]

Prior to combination valve there will be a 22mm iso. Pipework up to iso valve is a supply to, but not part of unvented cylinder.However, it may be good time to bring in G3 for cylinder's annual service check, clean filters, check pressure and maintain warranty.

 

[king of pipes]

I would say yes it will need to be re commissioned and checked as above time for a service and to keep your benchmark warranty up to date you will void your home insurance to so get G3 in who will have public liability for your own peace of mind .

 

[Kus]

Cylinder was only fitted about 5 months ago so not due a service. I am only upgrading the 15mm to 22mm up to the isolating valve so shouldn't any plumber be able to carry out the work

 

[Best]

I would guess if you don't touch the unvented unit or its parts, then upgrading the rest of mains pipe should do no harm. You can only be increasing the flow. But you need to get a G3 person to clean the filter.
One other point is do not join the mains to other taps or new outlets! Needs a G3 person to see that balanced supplies usually maintained and that nothing can back feed to the unvented unit!

 

[Kus]

Thats the problem with current supply as it tees off to kitchen sink and cloakroom with washing machine, wc and basin. Soon as downstairs tap is turned on shower drops to a trickle.

 

[Kus]

Can the kitchen tap come off the main or should it come off the balanced cold water

 

[Masood]

Should ideally be off the balanced feed but you'll only really notice if you have massive mains pressure. If it's 3 bar or under it won't make any difference.

 

[chris watkins]

For me kitchen cold should be directly off the high pressure mains the tap will need to be a divided flow if it is a mixer.
A few reasons but it does allow comparison between balanced side & incoming supply.

As cylinders are normally on the first floor seems a waste to run a balanced cold all the way back down to sink.

 

[magicno1]

Stick the combo valve on the mains water where it enters the building!

 

[ShaunCorbs]

Stick the combo valve on the mains water where it enters the building!

thats a big nono in my book, same place as cylinder is the best place