Is 22mm any better than 15 mm from loft tank to boiler

[LaT]

I have a boiler on the ground floor and am fitting a cold water storage tank in the attic to transmit pressure to the holier to then feed the bathroom. The pipework into the boiler is 15mm (its French). Would it make any difference if I used 15 mm pipe down to the boiler or 22m pipe, if it is going into 15mm at the boiler anyway?

 

[twgas]

Can you give more details on the boiler and system.

 

[spareshunter]

The pipework into the boiler is 15mm (its French).

or Irish (no offence) or old English.

If you don't know get a professional.

 

[Agile]

Few boilers are expecting to have a water supply from a loft tank!

Are you sure that you know what you are doing?

Nor do I understand your reference to 15 mm as being French. In France pipework is 14/16/18 mm !

Tony

 

[Terry lambert]

I'm guessing he has a French Combi

He wants to supply the cold to the boiler via a tank because he has poor mains pressure. He then wants to know if he would have a better performance from 22mm pipe.

If that's the case, if your installing a break tank, you could then pump the 15mm to feed the boiler.

Or just fit a Mains boos pump instead. This will increase your pressure by 1.6 bar and maintain 12 litres a min

Or I've completely misunderstood