orphanespresso wrote:My simplest approach is to follow the circuit along the hot wire beginning at the wall box. If a polarized socket the small flag of the plug is hot and should be on the right in the box with corresponding hot wire of your house circuit. The path then is hot to the power switch, through a he switch, to the pstat, through the thermal safety, On to the element. After the element (load)' I (likely incorrectly) think of as the neutral side of the circuit which returns to the neutral side of the switch and pilot light. So it is one big loop with a bunch of switches and one load. The lights count as a wire not a switch and are always closed. So if all the switches open and close properly your problem can only be some sort of mis wiring, which could include a bad light.

Verify proper function of all the components and keep tracking nag the circuit along the hot route and I am sure something will pop up to clarify your issue.

Hope this helps.

Very helpful. I'll start (actually, RE-start) tracing things later this evening. I do wonder, though, whether it is possible, if the hot and neutral are in the wrong positions going into the block on the power switch, that I could be bypassing the Pstat, which might explain why the machine still seems to be heating even after the Pstat clicks off ...?

soonerspresso wrote:I do wonder, though, whether it is possible, if the hot and neutral are in the wrong positions going into the block on the power switch, that I could be bypassing the Pstat, which might explain why the machine still seems to be heating even after the Pstat clicks off ...?

Generally it's prudent to wire it so that the hot side of the circuit goes to the pStat and thermofuse side of that circuit, but should work OK in a normal healthy machine if hot goes from the switch to the element, with the neutral going through the pStat and thermofuse.

However, there is this possibility: If all three of the below conditions are true:
1. Hot wire goes from switch to element (not through pStat)
2. There is a ground fault somewhere in the neutral side of that heater circuit (at the element or element insulator, perhaps even in wiring between element and pStat or in the pStat switch)
3. It is not on a working GFCI
Then you could have a situation where the machine heats even when the pStat is up to pressure and switched off.

This is one reason you always want to run these things on a working GFCI. It would trip right away in situations like the above, which helps to not only protect you but also to protect from frying things in the machine when a ground fault first occurs.

Sometimes these ground faults are difficult to detect with a multimeter, especially with a cheaper one. Electricians use a megger to help find them, which puts the circuit on a high voltage that can detect faults that may only show up under full voltage.

You can get a portable GFCI plug-in adapter at the hardware store if you don't have a GFCI protected outlet. If you already have it on a GFCI, use the test button to make sure it's working, and/or try plugging the machine into a different GFCI outlet. If it does not trip a working GFCI you can pretty much assume that you don't have a ground fault.

Updates before I go to bed:

1) Using a much better multimeter, I am getting a consistent 14.4 ohms between the heating elements. Not sure if that is within an acceptable range ...

2) I went out and bought a GCFI plug-in wall adapter. Plugged the machine in, turned it on, immediately tripped it. Clearly, The Force is Strong in homeburrero ...

3) I did tests on each wire to ensure that they weren't damaged or touching each other in any way (all wires appear solid).

4) I found that ONLY if I connect the HOT wire to the top left posts of the power switch can I interrupt the current upon depressing the Pstat. If the HOT wire is connected to the top right posts of the power switch, the current does not get interrupted to the boiler, even when the Pstat is manually depressed. However, even with the HOT and NEUTRAL wires reversed, the machine continues to trip the GCFI ...

This is demoralizing. Maybe a good night's rest will clear my head (or someone else can make some suggestions).

You now know you have a ground fault, just need to ferret it out. All testing should be done with the machine safely unplugged. If your multimeter has different Ohm ranges, set it to the highest range. And be careful to not touch the probes or the parts you are measuring with your fingers while measuring.*

First remove the wires to the element terminals, and carefully check to see if there is any continuity between either element connector and the metal base of the element. If you see anything but "OL" (or no continuity) you have a ground-shorted element. (If you do have a shorted element you may be able to fix it by following Doug's and Barb's 'So You Got a Cremina' videos.)

Then remove the two wires to the safety thermoswitch, and carefully check to see if there is any continuity between either of those connectors and the metal base and/or the grounding connector (the one with the green and yellow wire.) If you have continuity there you have a shorted thermoswitch that will need to be replaced.

Finally, remove the wires to the pStat switch and check to see if there is any continuity between the chassis (ground) and any one of those pins. There should be no continuity between any of those pins and ground. Check it with the pstat plunger pushed in as well just to make sure.

It's possible that you might have a ground fault that can't be detected with a typical multimeter, but it is always worth carefully checking first in the hope of finding it.

* It's not that the multimeter might shock you - it's just so that you don't measure the resistance through your body instead of between the parts you are trying to measure.

How about trying out the Livietta heating element in the Cremina? Should be a straight swap.

http://www.orphanespresso.com/Olympia-C ... 565-1.html

might help...
Barb

orphanespresso wrote:http://www.orphanespresso.com/Olympia-C ... 565-1.html
might help...
Barb

+1

That guide is nicely detailed and very well done, but doesn't get into ground fault checking. Doug and Barb have another excellent guide that does cover testing the element for a ground fault:
http://www.orphanespresso.com/Olympia-a ... 620-1.html

In your case if the element checks out OK you need to keep looking for the ground fault, per my earlier advice - it may be the thermoswitch or the pStat switch or even elsewhere in wiring between the pStat and the power switch (but is most likely an element.)

That's why I suggested trying out the Livietta element. If it works you know the Cremina element is the problem. The two elements are identical.

Yes, but first make sure the Livetta isn't also tripping the GFCI

To me it's best to first do the simple diagnostic test before swapping a part. Will take only a couple minutes with the ohmmeter and may save time, especially if the fault is found in the thermoswitch or pStat.

Good point!