Excuse ignorance but...I bought my 1930s North London semi last year. There is a gas boiler with a pressurised central heating system and pressurised hot water cylinder, and mains pressure cold water. On the top floor, converted from an attic into a bedroom and bathroom by the previous owners five years ago, is this pictured side space. On the right is the filling loop, pressure gauge and expansion vessel for the CH, all of which works as expected. But what is the large blue tank, which bears no labels or signage and has a single pipe feeding it? It looks like a large expansion tank for the cold water; but why should such a thing be necessary and how does it work? If the house pipework springs a leak and I cut off the mains feed from the road, must the cylinder drain before the leak will stop? FWIW the pressurised DHW cylinder is on the floor below and the boiler on the ground floor below that.
Apologies if obvious. I've dealt with gravity fed CH and DHW systems and with simple mains-pressure systems but not come across a tank like this before.
Apologies if obvious. I've dealt with gravity fed CH and DHW systems and with simple mains-pressure systems but not come across a tank like this before.
