hot and cold water storage

[munchman]

I have to replace my coldwater storage tank and hot water cylinder.
The problem is I can only get 86litre cwst and 116litre hot water cylinder

Is there regs that state sizes, and am I able to install these.
Thanks

 

[greyback]

Recommended you have same capacity of stored water in header tank as cylinder but as you are only a few litres out I wouldn't worry unless your demands for hot water are excessive.
You could join to header tanks together with 22mm pipe and tank connectors in line.

Make sure the new header tank is supported fully underneath and not with chipboard, use floorboarding or 3/4" ply across joists.

Incidentally you are supposed to notify your local building control of new cylinders being replaced/fitted. I will leave that one with you.