We have a 10 year old Andreja Premium (it does not have the three position power switch), and apart from a couple of pumps and some seals, it's been mostly trouble free, until now.

A couple of weeks ago it was sitting peacefully powered on, when it suddenly let loose with what sounded like a mighty gloosh of steam that brought us running to see what the trouble was. I thought perhaps overheating, so turned it off and let it cool. Since then the pump runs, water flows through, but there is no heating.
A phone consult and stepping through troubleshooting with Chris's coffee- major props to them- determined that the pressure stat was working, The limit switch was not the problem, and we saw 120V between the heater leads and ground. Their suggestion was to replace the heating element.

I've now replaced the heater, soldered up a couple of tiny leaks in the boiler, replaced the seals in the brew head, put it all back together, and... exactly the same. No heating happening.

I'm wondering if there are any suggestions for further troubleshooting. My wife is the engineer, and though she is more used to working with tiny DC circuits (our business involves instrumentation design) we have a pretty complete electronics lab here. The only schematic we have found doesn't exactly match what we have, but it's close. Ours has been modified with the kit from Chris's coffee to be directly plumbed in.

Failing that, are there any suggestions for repair services in the Seattle area? We are missing our espresso.

Thanks.

Did you check for continuity between the element's leads?

I am going to make the assumption that your machine is a 120V model.

If you see 120VAC between EACH element lead and ground, then there's an open switch or a broken wire on the neutral side. Possibly follow the wires to the safety thermostat and try to reset it, that's the easiest thing to do without pulling wires.

You can confirm that your neutral side is blue (Probably Blue, the machine is Italian) by (With the machine unplugged) pulling the blue wire off of the element (Tape it up for safety), then plug the machine back in, turn it on and see if the element still has 120VAC at each terminal. If so, it is still connected to phase. Follow the blue to find out why it is no longer connected to all the other blues... Pressostat open? Safety Thermostat dead?

Thanks for the replies. Yes, this is 120V. We got around to checking a bit more, and here are some observations:
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With Power unplugged:
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ST (Safety thermostat) is shorted
PSTAT is in the NC position

Measured resistance of the element is 10 ohms

Interesting note: The power cable from the wall plug is connected internally to the unit backwards from what one would expect and from what the schematic indicates. The black wire from the power cable (which is the hot side) is connected to the neutral terminal block inside the unit with all the blue wires and the white wire from the power cable is connected to the line terminal black inside the unit. As such the actual neutral wire is what is switched by the power switch, not the hot wire. It has always been this way since purchased new- for 10+ years.

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With Power plugged in and power switch in the OFF position:
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120 VAC to GND on each of the 4 connections to the SSR relay - 3/A1, 4/A2, 2/T1,1/L1
120 VAC to GND at the ST(Safety thermostat) and one side of the element
120 VAC to GND on the other side of the element (since it is connected to 2/T1)

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With Power plugged in and power switch in the ON position:
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Green power light is ON
Red Light is ON
Light on the SSR relay is ON

120 VAC across the control of the SSR relay 3/A1 and 4/A2
120 VAC across the load of the SSR relay 1/L1 and 2/T1

120 VAC to GND on both sides of the element

120 VAC between the Pin 7 and Pin 1 of the Gicar controller

Any insights are greatly appreciated. Thanks!

Pathfinder wrote:120 VAC across the control of the SSR relay 3/A1 and 4/A2
120 VAC across the load of the SSR relay 1/L1 and 2/T1

That's an AC control, normally open SSR. If you have 120VAC across the control terminals, and if you have a real load connected to the load terminals, then the switch should close, giving you near zero volts across the load (switched) terminals. So your SSR appears to be failed open. Note: If you just test the SSR without a load, touching the voltmeter probes to the unconnected load terminals, this isn't a valid test. See http://www.crydom.com/en/tech/newslette ... %20ssr.pdf .

Beware that hands or tools inside an energized espresso machine can be dangerous. Lots of opportunities in there to accidentally short and destroy a component, or worse. Even 110V can be deadly. A better way to test the SSR is to unplug the machine and wire in a test lamp in parallel with the load, then plug it in and test with your hands and voltmeter probes safely away from Mr. Sparky.

Thanks, that was helpful, we believe you are correct. A replacement relay is on order.

As built, the hot wire was connected to the neutral on the machine. It did become clearer to diagnose when we switched the neutral input from the mains supply and connected it to the neutral on the machine. I think this being reversed confused the tech at Chris's coffee in that we had voltage where you would not expect. Possibly this led him to suggest a bad heating element, which we don't think we had.

However, with the the input connected in this way- neutral from the mains to neutral on the machine- whenever the brew switch was engaged it flipped the GFI. So we switched it back to the way it was originally. Bypassing the relay temporarily has the heater working fine. We don't understand why the machine is wired like this with the switch in the neutral (to do with the controller?), but it has worked for 10+ years that way...

Thanks for the help.

Pathfinder wrote:As built, the hot wire was connected to the neutral on the machine. It did become clearer to diagnose when we switched the neutral input from the mains supply and connected it to the neutral on the machine. I think this being reversed confused the tech at Chris's coffee in that we had voltage where you would not expect. Possibly this led him to suggest a bad heating element, which we don't think we had.

However, with the the input connected in this way- neutral from the mains to neutral on the machine- whenever the brew switch was engaged it flipped the GFI. So we switched it back to the way it was originally. Bypassing the relay temporarily has the heater working fine. We don't understand why the machine is wired like this with the switch in the neutral (to do with the controller?), but it has worked for 10+ years that way...

It's not that uncommon to see Italian machines wired like this, and generally they will work fine if you swap line for neutral on the supply. Note that modern Shuko plugs and type L Italian plugs are non-polarized - so which one is actually 'line' and which one is 'neutral' depends on how you happen to put the plug into the receptacle, and the machines are designed to allow for that.

It's not really normal that your machine trips the GFI the way it does. That indicates a ground fault on one side of the brew/pump circuit that is enough to trip the GFI if that side happens to be the hot side. I suspect that may explain why yours is wired the way it is.

Thanks for the info. We ordered a new relay- not the exact same part but supposedly an equivalent replacement for the discontinued Isomac we have (same part #). This is the Crouzett Solid State relay 84137011. At the same time I got all the parts and rebuilt the brew head. Great joy ensued when the machine heated and appeared to be working.

However, the instant the machine reached temperature and the relay turned off the heating element, the GFI tripped. Subsequent attempts to plug in the machine also immediately tripped the GFI, even with the switch in the off position. That is, until the machine had cooled, when I was able to plug it in again and again it heated the water to a point when the relay switched and it tripped the GFI again.

So reaching temperature = tripping GFI. The only thing that has changed electrically so far as we know is the new relay. However the machine has been mechanically disassembled, though I did not remove the wiring harness. We are a little puzzled as to the logic- the schematic is not clear and doesn't quite match what we have, particularly around the controller. Any thoughts on where to start probing?

Thanks!

Intermittent ground faults can be difficult to ferret out. One thing you can try first would be to replace the safety thermoswitch with a simple jumper wire and see if the problem goes away. Not a likely cause but easy to test. If your machine has the green 'ready' lamp wired into the NO pin of the pressurestat you might want to disconnect that from the circuit and see if that solves it. Hard to even guess without seeing a wiring diagram of your machine. ( Is it perhaps like this one, but with line and neutral swapped?)

A repair shop with an insulation tester (aka megger) might be your best bet here. They can bring the machine up to temp, then unplug it and safely test wires and components to pinpoint the cause of the ground fault.

After being out of town for a couple of weeks, I plunged back into this. It now seems solved, and I have a tentative hypothesis as to what happened.

I noticed that there was a small leak in the boiler, which I traced to my not having sufficiently impact-tightened the new heater element. I took it all apart again, reassembling with extra care to make sure no wires were touching anything they should not be. We are now working perfectly, no more tripping of the GFI- I'm guessing the leak was what was causing the ground fault.

The original scenario was I suspect caused by the failed relay leaving the heater on until the overpressure blew off suddenly- resulting in the big noise we heard. The wiring having hot and neutral reversed seems to have caused enough confusion over the phone that the technician we talked to suggested the heating element was bad, however the problem was actually the relay all along. With the relay replaced and the leak fixed, everything seems to be working. As a bonus I finally got around to plumbing in the machine directly.

Many thinks for the suggestions and support.