Your pStat may be OK, but is hard to tell from your description. That one long sentence was pretty hard to decipher.

To adjust the pStat you need a working gauge and a working safety valve.

Please do this:
1. Set the pStat where it was before (so that the water boils.)
2. Turn on the machine, and record the time.
3. Record the time when you hear the water start to boil (and see it fluctuating up and down in the sight glass.)
4. Record the time when the safety valve starts to hiss.

Report back on that.

I'm thinking that might help tell us whether your problem is in the safety valve. It still is possible that the pStat is OK, the gauge is OK and you first need to fix that valve.

Just found a recent post about checking that safety valve: La Pavoni Europiccola pressure release, releasing a torrent of steam

Make sure there aren't pieces of goo or scale keeping it from sealing in the orifice. If it's a steel ball make sure it's not pitted or corroded. Make sure the orifice is clean and smooth. The spring may look like the one in the pic above, or may have only about six coils. Instead of a steel ball you may have the newer (and better) plastic mushroom that seals against the orifice.

If a bad safety valve is causing you to show zero pressure on the gauge, it would need to be pretty bad. But still hope this might be the problem.

I just took off the safety valve, it looks pretty clean. There is no goo on it like there was on the pressure gauge or the pressurestat.

I timed the time it takes until the water brews, and it happens at 3 minutes. From there, it takes another 4:30 minutes until hot air and water starts spewing from the safety valve. So it takes a total of 7:30 minutes until the hot steam is escaping from the safety valve.

Yeah, Im sorry about the long confusing sentence. My assumption is that the function of the pressurestat is to cut off power to the heating element at a certain point. The adjusting screw would adjust at which point in time the power would cut off. At its lowest range, the pressurestat will never allow the heating element to be powered, and at the highest range, the power would never be cut off, leading to the water going to boiling state and escaping from the safety valve. I was trying to say that my pressurestat operates only at the highest and lowest range, there doesnt seem to be middle ground in between, as there should be.

You should post a pic of YOUR machine. I'm not LP knowledgeable by any means (I do have one) but there exists a variety of LP configurations.

You certainly need to get that pressure gage working and adjust a working pstat such that the maximum pressure you see is 0.80 bar (as a starting point).

ecks wrote:I just took off the safety valve, it looks pretty clean.

Darn. Was hoping that was it. I assume the steel ball is shiny and not corroded. Sounds like the safety valve is OK and is looking more likely that you have both a bad gauge and a bad pStat.

ecks wrote:I was trying to say that my pressurestat operates only at the highest and lowest range, there doesnt seem to be middle ground in between, as there should be.

That would be the case if it were clogged, stuck, or the diaphragm were bad.

I think you have this type of pStat, no?


If so, here's how you might want to set it at a very low initial setting in the absence of a gauge:
1. unplug the machine, remove the wires from the pStat and connect an ohmmeter or conductivity tester to those two terminals.
2. loosen the little set screw, then turn the adjusting screw anti-clockwise until you have no continuity between the terminals.
3. turn the adjusting screw clockwise to just the point where you have continuity.
4. turn the adjusting screw clockwise 1/2 turn further.
5. tighten the set screw and replace the wires.

This should set it so that it cuts off at a low pressure, maybe 0.4 bar or so, which will help you test and decide if it truly has no middle ground and the diaphragm is not working. If you think it may just be scale clogged, you could at this point try the rpavlis method discussed here:

rpavlis wrote in La Pavoni Professional find
Dilute white vinegar about 1 to 1 with water and fill the machine with this. Put on the lid and bring up to pressure. Let the machine cool, and, without draining, bring up to pressure again. Do at least three or four heat cool cycles.

Or you could just go ahead and put an order in now for both a new gauge and pStat.

Yeah, the pressurestat pictured is exactly the one I have. Ill try that test with the multimeter tomorrow morning. Can I buy a replaceable pstat such as this one: http://www.cafeparts.com/productDetail1 ... emID=68355? I dont think a pstat like the one I have is carried anymore, too old. Any other places to get la pavoni parts from?

I believe that one will work. Another shop that carries a lot of Pavoni replacement parts is Stefano's Espressocare. He sells an adjustable pressurestat for the pro that is like what comes on the newer models. (The one just like your old one is unavailable.)

Stefano is an HB sponsor, and is very knowledgeable and helpful when it comes to La Pavoni home levers. Has other things you may need - like replacement gauges, including brass ones at affordable prices. Also has the flat boiler gasket that goes with your machine, the pre-millennium gasket kit, and the teflon mushroom safety valve kit.