MetalDave Flow control gauge only shows pressure if there is a blind filter or puck under it, or if the flow control is closed.
The flow control gauge on the group (let’s call it the group pressure gauge from now on) Should not show any pressure with the flow control closed, unless it’s against a blind filter and fully closed is not completely closed. With no portafilter the group gauge should never show pressure.
MetalDave If you think this might be a faulty pump, I will keep an ear (and eye on that) - the problen did not duplicate itself again this morning, so hopefully this was an anomaly that has passed.
I hope so, pumps can be intermittently faulty, but it’s rare. It could also be something blocking thew inlet side sometimes.
Are you using a water filter attached to the end of the pump inlet hose?