Why is my espresso machine tripping the GFCI when cold, but not hot?

#1: Post by **quar** » July 24th, 2013, 6:50 pm

Hi all,

My Anita just started tripping my GFCI outlet when plugged in. The power switch can be off or on, doesn't matter. Weird thing is that it only does it when it's been off for a while. If I plug it into a non-gfci outlet and let the temp. come up, even for a few minutes, it's fine when plugged back into the GFCI. If I switch off and let it cool down long enough, the GFCI trips. I've read posts about the heater element causing outlets to trip when they get hot, or about machines that trip all of the time, but not one that trips only when cold. I'm assuming it's some strange failure mode of the element, but thought I'd get second opinions.

Thanks,
Mike

#2: Post by **another_jim** » July 24th, 2013, 8:47 pm

The most likely reason is that a wire is touching the boiler when it's cold and not when it's expanded and hot. The most likely candidate is the auto-fill wire, and the wiring to the heater, pressurestat, and boiler refill solenoid. A discrete tug on these may fix the problem.

http://users.rcn.com/erics/ · #3: Post by **erics** » July 24th, 2013, 9:54 pm

Here is an electrical schematic for your Anita - http://users.rcn.com/erics/Illustrations/QM_ELEC_1.jpg

As a ballpark guess, about half of the Quickmill machines were wired incorrectly(?) at the terminal strip such that neutral and hot were reversed . . . this does not cause your problem but could affect troubleshooting.

A first step might be to disconnect one lead from the heating element and repeat the experiment.

July 24th, 2013, 10:05 pm

Thanks guys, I'll check out the wiring and try disconnecting the element if I don't see anything else wrong. It's one of the first fifty Anitas, so I'm not sure where that lies with regards to the reversed wiring.

Mike

July 25th, 2013, 11:30 pm

OK, I've taken the cover off and everything looked OK. When I pulled the leads off the element, it stopped tripping the GFCI. I found that it was the lead on the right that leads to the emergency over temp switch, then to the power switch causing the problem. I could plug the other lead into the element with no problem. I've tested the element and it's reading 8.9 ohms, which I think is in the right range for an Anita. Now I'm thinking that it's the over temp switch. Other than jumping the switch, is there a good test to make sure this is the culprit?

Mike

#6: Post by **another_jim** » July 26th, 2013, 12:02 am

Take the leads off and measure the resistance (in megaohms) between each terminal and ground (the boiler surface will do). If there's anything other than an open circuit, it can't be enough to trip the GFCI (which are far more finicky than they need to be).

You do need the safety over the long run, since it can save your heating element if the tank empties or the boiler gets low; but if it's the culprit, you leave it out of the circuit for the few days it takes to replace it without running a huge amount of risk.

#7: Post by **Randy G.** » July 26th, 2013, 12:26 am

My original thought was a pinhole in the element IS allowing water to seep in overnight. Trips GFCI when cold in the morning. If plugged into standard outlet and allowed to warm up, the water is vaporized out of the element and now does not trip GFCI.