You guys just won't let me throw parts at the problem will you?

Habits die hard. In the end, you may just end up replacing the pump but that will be an adventure in and by itself.

The fitting on the OPV would need to be removed and this will reveal the adjustment "screw".

This machine needs a little TLC.

Eric,
I removed the black cube (near C:boiler fill solenoid?) from it's post and disconnected the water line going into the bottom of the boiler. When I powered the machine up, the pump engaged without me hitting the brew switch and water came out the OPV valve. No water came out of the grouphead. So I removed the OPV valve and disassembled.



I guess it's stuck open. I can't budge the protruding cylinder in the middle. Do I fix it or order a new one? Chris Coffee doesn't seem to carry them.

Thanks again for the help.

Gio

My fault for the pump starting up - that's the autofill kicking in and I took care of the fill solenoid but forgot about the pump part.

Anyway - you MAY need to fashion a special tool to loosen/remove the OPV adjusting screw or you could get lucky and try turning it with a beefy screwdriver in half of the slot. The OPV that Chris' Coffee sells for the Quickmill line will work fine but I would disassemble the one you have just so you can get a better understanding of how it operates. Here is what the Quickmill OPV looks like:

I put a small flat head screw driver on each side. Then I crossed them and used them as leverage against each other to unscrew it. As far as I can tell, the spring is just compressed so much that the valve is permanently open. I just ordered a new one along with a pump from Chris Coffee. I'll report back when I get everything bolted back together.

Oh yeah, I made a pressure gauge so I'll be able to adjust the new OPV when it arrives.

A pic(s) of the internals would be helpful for future readers. And, BTW, the heavily compressed spring would have likely kept the valve shut (assuming the valve still has a life-form).

Here are the internals:



It appears that the black gasket/seat is the only thing preventing water from passing through the valve. You can see a pretty good permanent indentation.



I saw that Chris Coffee sells a "replacement seat for expansion valve," but it doesn't look like it would fit this particular valve.

Earlier, you had said:

When I powered the machine up, the pump engaged without me hitting the brew switch and water came out the OPV valve.

That tells me that the OPV has failed in some manner. The impression you have in your rubber valve face is normal - very similar to the impression that is shown in this steam valve face:



In your case, it is the impression of the valve seat which is inside the large hexagonal body at the threaded end. It is entirely possible that the seat is slightly damaged or there is a piece of "whoknowswhat" on the seat. Because the movement of this valve during normal operation or during blind filter operation is VERY SMALL (about a tenth of an inch at the very most), it doesn't take much to upset operation.