Rancilio Silvia - heating element replacement & steam valve problem

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by Greenwichpaul »

HI folks, I hope you are all well and enjoying your daily caffeine infusion. Which I am not.

My V4 Rancilio Silvia tripped the house RCD a few days ago, then seemed to work ok. There was some sludge in the OPV valve which I dismantled and cleaned. Worked OK. But then three days ago it tripped the RCD again, consistently. I decided there was a high chance the element had blown. I did leave the machine on for a long time around 7 days ago, which might have been the final straw. It's still on its original element, which is possibly a surprise as we often do house swaps and I doubt my guests are as religious about keeping the boiler full as I am.

Now I've taken apart the boiler, am looking at the element and it doesn't show obvious signs of failure. There was a LOT of sludge in the bottom. I haven't taken the element out yet as I don't have a wrench big enough (is it 23mm?). There are I think signs of scorching on the heating connections and the plastic covers of the connectors are very yellows (although I would assume they would be).

My resistance readings are 50 ohms across the heater terminals, and approx 200k to ground for both. Does that sound like a blown element? Of course, if not, please suggest what the problem could be.

The machine has run pretty well for the last 6 or 7 years, I descale quite often but probably not often enough given we are in a area with v hard water.

Supporter ♡

#2: Post by ira »

200K to ground is a problem that will set off GFI outlets. And while I don't know, 50 ohms implies a 250 watt element which seems very small for an espresso machine.

edit: you're in London so 500 w which might be OK.


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#3: Post by JRising »

I agree with Ira,
50 ohms is too high, the filament in the element is damaged.
200k to ground is not good. The element is damaged, dampness has gotten in and provided a short to ground and the filament is damaged in the burnt section near that spot where the damp got in.

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BaristaBoy E61

#4: Post by BaristaBoy E61 » replying to JRising »


Another country heard from. :D
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

Greenwichpaul (original poster)

#5: Post by Greenwichpaul (original poster) »

Well, if it walks like a duck and quacks like a duck....

I thought the 50ohm seemed reasonable as that equates to about 1.2kW (v squared/r) according to my calculations.

But I take your advice that it's the 200k to earth that's the killer. I'll order the element, also I need the seals to overhaul the steam valve as that's weeping, and I will report back.Thanks for the advice.

Greenwichpaul (original poster)

#6: Post by Greenwichpaul (original poster) »

Update: I replaced the element and the RCD no longer blows. Heats up, produces hot water etc ok. This is despite their being no visible flaws to the old element which looks in pretty good condition. SO, a relief, and the advice here was correct, thanks.

What I thought was a minor leak from the steam/water valve is a pretty major leak. There is quite a lot of water coming straight out of the valve itself, at the end where the steam knob attaches. It leaks directly from the middle as shown in the pic. I suspect there's been a good leak there for a while due to the rust on the steam knob clip.

I rebuilt part of the steam valve, ie the spring and washers for the steam wand, but haven't rebuilt the valve itself as I couldn't remove the 23mm nut. I remember that 23mm is useful for this, plus the OPV valve, and I think for the earlier Gaggias too, so I have two 23mm wrenches on the way. I hope the espresso shop rebuild kit will fix it.

And now I think I'm going to buy a Flair Espresso Classic to get me through the next few days and as backup for similar crises.

BTW, for those doing an element swap the wrench sizes are
18mm (smaller steam valve nut)
23mm (steam valve and OPV valve nutes)
28mm (element)

Greenwichpaul (original poster)

#7: Post by Greenwichpaul (original poster) »

Despite buying exactly the right wrenches, I still couldn't shift the main nut on the steam valve... in the end my wonderful wife walked down to a local car mechanic and got them to release it. I think that scale was responsible, as well as the tightness with which the factory fits it. Both the washer and o rings were totally shot. This was really a reminder to check the internals every year or so and look out for water dripping down from the steam wand, as the valve has obviously been leaking water for months.

I reassembled and everything ... sort of... runs as it should. No leaks at the pump or boiler. But I am getting water seeping out at the steam valve again. I'm also finding it hard placing the steam valve exactly correctly. I did it what I now know is the correct way but was getting binding of the steam knob. I believe the pic below shows it incorretly, the serrated washer should be on the valve side. I got some weeping at the brass nut which clamps down the copper pipe to the boiler, that stopped on tightening. However, once that was tightened, then I got water weeping, in greater quantitites, at the point you can see below, which seems to be at the main bolt, ie the bright silver one, around the location of copper washer, Part 9 in the exploded parts diagram.

I fitted it fairly tight, obviously I was worried about refitting as tight as the factory version so it's impossible to remove next time. I am pretty certain I fitted the copper washer in the right location.

Is there any error I could have made with reassembly that causes the leak? Or will a bit more force on the wrench solve the leak?

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Greenwichpaul (original poster)

#8: Post by Greenwichpaul (original poster) »

All running well. When I took the steam valve apart again I'd missed the copper washer.

Coffee tastes fantastic. Thanks for support and sympathy, all