I barely understand gas boilers and how they are plumbed in... so bear with my question! Apologies for the length!
My Vokera Mynute boiler pressure guage has always been low - in fact close to 0 bar (around 0.1~0.2 bar). Red zone for this boiler is 0 to 0.5 bar!
I had it checked & serviced today and the RGI technician said the boiler was fine but that the water pressure should really be ~0.75bar (out of the red zone). He looked in my hot press and opened/closed some valve in
a pipe running alongside the hot tank. He says this is the valve that fills up the radiator system from the attic tank. He was surprised not to hear any sound of water travelling thru the pipe... and suggested I get a plumber to look at the valve. He suspected that the valve was blocked or the pipe air-locked.
Any ideas what is causing the boiler low pressure?
Is it harmful?
What do you recommend?
Should this hotpress "fill-up" valve be open all the time?
I traced the pipe with the fill-up valve and it does indeed go between the smaller of my 2 attic tanks... and something big pipe at the bottom of my hot tank. There are actually 3 valves on this pipe.... highest was an old wheel handle one, middle was the one the RGI man twiddled, bottom is another similar to middle but only operated by screwdriver.
I unscrewed the flex pipe below the middle valve... and then could confirm/check that water could come thru the other 2 valves just fine.
If I turn off the valve, the boiler doesn't like it and shuts down, with lots of gurgling sounds. When I turn the value on, the boiler comes on... but got lots of gurgling in the radiators - I then bled some air out of one the rads.
I notice that with the fill-up valve open... that that pipe that goes up into the attic is quite hot.
Question: Does this mean hot water is being pushed all the way up into the attic water tank?
I very much appreciate any help/tips!
Thank in advance.