Just had pump replaced (set on 3) a few weeks ago. potterton
kingfisher, vented, 3 port valve in 3 bed semi. When on ch and hw the
system runs fine, no noise coming from boiler or the system as a whole.
When on hw only, theres a terrible racket with noise coming from the
pump as if theres lots of air in the system. what I dont understand is
if there is air in the system, why doesn't it happen when both ch & hw
is on? Any ideas?