My aging father has a common combi (5yr + Vaillant /3 bed semi)pressure issue.
It all starts when he complains the rads need bleeding, dutiful son bleeds rads, reset pressure and feels smug until I notice pressure is too high. I reset the pressure, it now swings from 0.8 cold to 2.0 hot (just in the green zone) and suggest he calls in an engineer. The engineer does a service and says ?the pressure is ok if it stays in the green zone?.
All?s well for a couple of months and then the call came ? boiler won?t start, there?s no pressure.
I reset the pressure to min (0.8 cold) and strike it up, only this time pressure rises to 2.5 bar ? suggest he calls in engineer who (despite an explanation)infers some idiot has put in too much water and drains some out of the hot system.
Next day, see above except engineer has lost interest and suggests we call someone else!
Engineer #2 advises ?it?s ok as long as the pressure doesn?t rise above
3.0 bar?.Am I the only one who thinks the EV or something else may be faulty or do you think this is good advice?
TIA, John