Mains water pipe from 15mm to 22mm ok?

[inigo]

Hi, I am trying to get rid of my water tank in my flat with minimum replumbing.

Is it possible to connect the incoming 15 mm mains pipe to a 22mm pipe that serves the flat? Are there any consequences such as loss of pressure?

Note that the pipe also supplies the sink tap and boiler.

Thanks
Inigo

 

[inigo]

Just to clarify that it is the 15mm mains inlet that serves the sink and boiler!

And if it makes a difference, I live in an area with decent water pressure. Thanks

 

[twgas]

what does the tank currently supply

 

[Bahco]

I live in an area with decent water pressure.

I can't see it being a problem if your pressure is ok. 22 is not the done thing due to cost but if it is already in situ carry on and report back.

 

[TicklyT]

I hope you don't intend feeding mains pressure water into an open vented hot water storage cylinder Open vented cylinders are not designed to work at mains water pressures, and things will get very messy and very wet very quickly if you try.

Unvented cylinders are available, but they are very different animals, with a whole range of safety features to stop them going bang, and it is a safety requirement that they should only be installed by a plumber with appropriate qualifications.

If you have a combi boiler supplying instant hot water, then the changes you propose are OK.

 

[inigo]

ah - its a combi boiler - whoever installed it either didn't bother disconnecting the tanks from the cold water supply or thought they were being considerate in keeping the toilet flush separate!

OK...so i have decent pressure so i'm gonna go for it!