Hi all

So I've got my new andreja premium, and have a question about the pressure gauge reading.

The boiler pressure gauge is fine - reading about 1.2 once the machine has heated up.

I'm a bit confused about the brew pressure gauge though - once heated up, this actually reads a baseline 4.0 bars (but goes up to 10 bars during the extraction). I thought that at baseline the pressure gauge is meant to read 0 - or am I misunderstanding things?

Once I release the pressure, the gauge goes down slightly, to around 9 bars (and there's the foosh of water out the pressure release pipe), but then stays there. If I then run the pump without a PF locked in, the pressure drops a little to 4 bars, but doesn't go below that. Plus I get water going out through the pressure release pipe (even though there's nothing in the group head!) Is something wrong?

P/S: a video demonstrating it is below

Thanks
Sing

As Eric noted, the brew pressure gauge reading is relevant when the pump is running, but otherwise isn't useful. I elaborated on this point in Brew pressure rising during warm up:

HB wrote:As water heats, it expands; since a boiler/heat exchanger is a closed system, the pressure rises. It's nothing to worry about since the expansion valve opens to relieve pressure as required. The expansion valve is typically set to open around 12 bar for rotary pump espresso machines since they have their own bypass valve to regulate brew pressure. For vibratory pump espresso machines, the expansion valve (traditionally called an over-pressure valve in this context) is set to open at the desired maximum brew pressure, usually around 9 bar.

In a nutshell, the brew gauge reading should fall to 0 when you lift the lever and then rise to the pump's set point. When idle, the reading is the pressure in the heat exchanger due to water expansion.

Unless you have a plumbed in machine, then you get the static line pressure from your mains on the brew gauge. Most vibe pump machines read about a bar to 1.5 bars high on the gauge compared to the actual group head pressure so if you are getting 10 bars during an extraction, it is probably closer to 8.5-9 bar at the group head.