"Matty F" wrote in message
...
On Sep 25, 7:39 pm, "Man at B&Q" wrote:
On Sep 25, 1:35 am, Matty F wrote:

We tend not to have header tanks here. I've only ever seen one, and
only because I was fixing it after a tradesman had failed. I don't
understand the need for them, since there are better and cheaper ways
of getting the pressure right.

They're not about getting the pressure right.

What are they for? Breeding mosquitoes and cockroaches and rats?
Putting lots of weight on the ceiling so it collapses?

Like anything else when water is heated it expands. The header tank acts
as a cheap and cheerful safety valve allowing any excess volume of water
to feed back into the tank rather than cause leaks at the joints through
increased pressure.


michael adams