hot water system All aspects of plumbing questions and answers, help, tips and information

[raymondo]

i am about to install a bathroom on 1st floor, already have g/f shower room. Hot water is supplied by a combi boiler via an unvented system. the boiler and cylinder are both at g/f level, my question is..will there be enough pressure in this system to feed the new bathroom on first floor? thanks.

[bobplum]

should do as the presuue from the system should be enough you may want to run it in 22 mm pipe as far as you can

[raymondo]

thanks bobplum....i intended to run the feed in 22mm anyway, just wanted confirmation because not extended an unvented system before.

[htg engineer]

A combi boiler works on mains pressure, there should be no problem with the pressure to the bathroom.

Do not run the hot water supply in 22mm. The mains to the boiler is 15mm so the pipwork from the boiler should be 15mm.

Increasing the pipe size to 22mm will not increase the pressure, if anything it will decrease it.