Rancilio Silvia trips GFCI

#1: Post by **rharries** » July 27th, 2022, 9:31 am

After a recent de-scaling my Rancilio Silvia (V3) has started to trip the GFCI outlet while warming up. I have reviewed a few archive threads on this matter, and am ready to replace the heating element.
One comment made by "civ" in this thread:
Heating element? Rancilio Silvia makes GFCI outlet trip with power switch flipped on
has me wondering if I simply need to re-seal the terminal insulation, as it appears there is no resin there presently:

Additional information:
1. The heating element was replaced just last year and appears to be in excellent condition
2. Resistance across the terminals is ~17 ohms
3. There is no continuity from either terminal to the boiler body

I am willing to try the resin sealant while i await delivery of a new element from Rancilio, however i am looking for advice on how to re-seal with resin. what type of product is used?

Thanks for your advice!

#2: Post by **cafeIKE** » July 27th, 2022, 9:45 am

rharries wrote:3. There is no continuity from either terminal to the boiler body

On what scale are you measuring resistance from the element to the ground terminal? GFCI trip on a few mA, ≈5. On 120VAC, that current occurs @ ≈34kΩ

See Chasing "ghost" trips in GFCI-protected circuits

#3: Post by **JRising** » July 27th, 2022, 10:50 am

Unplug it, take both leads off the element (and safely insulate them against touching anything), plug it back in and turn it on.
If it no longer shorts out, unplug it, reconnect the element, plug it in and see if it returns. Very often 120Volts can find a short more easily than the 9V battery in a multimeter.

#4: Post by **cafeIKE** » July 27th, 2022, 11:28 am

Technically, GFCI trip current is not a short.

Disconnecting the element will reveal whether the fault lies there or elsewhere.

#5: Post by **Pressino** » July 27th, 2022, 11:42 am

I wonder about the scale in the photo, I suspect whatever it is allows some small amount of current to flow from the supply to the casing, just enough to trip the GFCI, especially if there is enough moisture around it. Does look like it is a little moist.

July 28th, 2022, 8:58 am

Thanks for all the replies.
cafeike - I was measuring resistance using the 200 setting on my multimeter, which I believe is the lowest available.
Pressino - There was no moisture present when the tripping occurred, the moisture in the photo may be remnant alcohol from my cleaning attempt to inspect the insulator sealant.

I will re-assemble and test to see if the fault lies elsewhere, however i would like to apply resin sealant prior to assembly. what type of product is used for this? is it readily available at hardware stores?