My Quickmill Aquila Deluxe (rotary pump model) worked great for 10 years up to the other week, the safety vacuum breaker valve (vbv) went off blowing off steam so I had to shut off the unit.

I turned it on again watching the boiler gauge as the pressure continued past the standard 1.2 bar and doesn't turn off automatically. As it continues heating past the max 2.5 bars the vbv releases again.

After running some tests I ruled out the sensors since it continue to engage the pump to refill the boiler and also running the group head. So I determined the culprit is possibly the pressure stat going out. This unit uses the discontinued Jaeger PS 15.01 which is pretty much impossible to find at a reasonable cost. I was able to locate a similar pressure stat part (GI.365) also known as the 16.01 model from 1st-Line (where I originally purchased the machine too). From researching the limited info on the web, and really old posts on this forum, my understanding is the main difference between the parts are the pressure adjustment range:

PS 15.01: 0.9-1.7 bar
PS 16.01: 1.5-2.8 bar.

I ordered the 16.01 part since that was the closest thing I could find that is available and I would just set it to the lowest 1.5 bar setting which I hope would still be within a safe pressure range (from the 1.2 standard setting).

So the 16.01 part arrived and I installed it. Then I fired up the machine, green and orange led light comes on, I can hear the boiler heating up but I noticed the pressure gauge does not move and stays idle on zero. Every few seconds the meter does a small shake but barely moves from 0. Clearly the boiler and grouphead are heating up, but the gauge remains the same for some reason?

When I run the grouphead, it engages the pump. But meter stays idle at 0. Does this mean the 16.01 is not compatible? Faulty?

I looked into other pressure stats such as Mater, Lefoo, and Sirai if anyone can suggest those as good compatible alternatives as well. Definitely much cheaper for the Mater and Lefoo brands.

No. It probably means that the capillary for the gauge is plugged.

But what matters is whether the replacement p-stat has fixed the over-pressure problem. Get the gauge working again and see if the boiler reliably stops heating at 1.5 bar. Then enjoy an espresso.

JRising wrote:No. It probably means that the capillary for the gauge is plugged.

Did you mean to say un-plugged?

I checked and it's on tight (didn't remove during pstat replacement).

No... Plugged, like "plugged up" or clogged... It's probably got a blockage of calcium at the boiler end. If you know that there's pressure building in the boiler, but the gauge isn't reading it, either the gauge is seized (rare if they haven't been physically damaged) or the capillary is clogged.

Gotcha, thanks!

I opened up the line and checked the boiler end and it had a bit of residue. Wiped it off and reinstalled it. I went ahead and took out the temp probe and cleaned it while I was at it which had a touch of residue as well. I fired up the machine and bam, it began to heat up and the gauge kicked in after about 5 minutes once the pressure built up to 1.2 bar (perfect) with the new pressure stat set to lowest setting (counterclockwise).

So now it appears machine is up and running for about an hour now with the pressure stat consistently engaging the boiler heater and orange led once it drops below 1.2 bar. However, I do notice something a bit off, but I'm not sure the boiler pump is engaging to fill the boiler? How do I confirm or "force" the pump to run and fill the boiler?

I can engage the pump via the group head lever which works fine, but I guess I'm used to the pump running automatically every now and then to fill/top-off the boiler. I just wanted to make absolutely sure it's working so the boiler coil doesn't get damaged.

TYIA!

Ok I answered my own question by removing the water level probe connector. It engaged the pump.

So if I understand this correctly, this verifies the controller and ssr are working, as with the solenoid is working properly opening when called upon?

What else should I look for?

I think you're done.

The new P-Stat is allowing the boiler to heat to 1.2 Bar, then shutting off the element?
You've won, your prize is a nice cup of espresso, but you have to brew it yourself.

SWEET! Thanks for the help guys!