Had an Vaillant engineer over a couple of days ago to replace a leaking pump.
When the heating is off the pressure is around 1 bar, when it’s on it climbs to 2.8 bar, which is much higher than I’ve ever seen.
He tested the expansion vessel when he was here and checked it again today and it’s fine.
What could be causing the high pressure?
thanks!
When the heating is off the pressure is around 1 bar, when it’s on it climbs to 2.8 bar, which is much higher than I’ve ever seen.
He tested the expansion vessel when he was here and checked it again today and it’s fine.
What could be causing the high pressure?
thanks!