I have several questions coming up, but I'll start with this one.
I have a Gas CH system that has been converted to a fully pumped
system, previously pumped heating, gravity HW.
The installer used two port zone valves for each circuit, and as it
had been previously gravity fed (I assume this is the reason) the HW
circuit is all in 28mm pipework - except for the zone valve! He has
used a 28mm-22mm converter either side of the HW zone valve which is
2. Will it actually make much difference?
Many thanks for any info.