In article ,
Owain wrote:
One particular reason for a pressurised system in your application,
where the property is, I surmise, likely to be unoccupied for periods of
time, is that if there is a leak the amount of water in a pressurised
system is finite. If a vented system leaks there is an unlimited amount
of water to cause damage because the system is continually replenished
from the header tank.

If this really is a problem, you could fit a stopcock to the header tank
feed - under normal circumstances there will be enough water in the header
tank for a couple of years - if not more.

--
*I'm not being rude. You're just insignificant

Dave Plowman London SW
To e-mail, change noise into sound.