Anti backflow valve causing pressure
To reclaim valuable kitchen bench space, recently I relocated my Grimac Eclisse from its plumbed-in location, to its own cabinet.
But unfortunately, away from mains water.
So I'm trialling it on tank water, the tank being a 10 litre supermarket water container.
It has a rotary pump which may or may not be a self-priming Procon--on the face it has a sticker with Grimac on it. Eleven years ago when I bought the machine it happily self-primed from a similar setup. But now I had a devil of a time getting it to draw. Many times I had to crack open the line to the brew pressure gauge to expel any air.
And even after getting it to work, sometimes it would splutter and stop mid brew. Maybe it's showing its age.
So I screwed an anti backflow valve from Bunnings to the end of the hose which goes into the container, and this has eliminated that problem....
....while creating a new one. As the machine begins heating from cold, I'm guessing cold water in the lines begins to expand as the thermosyphon action kicks in. The anti backflow valve keeps the water in the lines in check, and having nowhere to go, pressure builds up -- to 12+ bars as seen in the photo.
To bring the pressure back to zero, I have to momentarily use the brew touchpads, or push in the now redundant manual boiler fill valve (which needs mains pressure to work)
Short of reverting to a plumbed-in state, how can I stop this happening?
I do like the anti backflow valve because (a) it works, and (b) it allows me to remove the hose while I take the container to the sink for its weekly filling with under-sink filtered water.