# Silvia - no steam - troubleshooting help please



## mpmcgowan (Jul 2, 2016)

I posted this on the rancilio forum, but with no responses, so I'm re-posting here in the hope that someone with a hint, tip, suggestion or fantastic insight might be able to help me out.

Miss Silvia has stopped producing steam!

When I turn her on, the Big Orange Light (BOL) comes on, and the boiler heats up. When up to temp, the boiler goes through it's cycle as you'd expect. Hot water is produced at the group head, as normal.

When the steam switch is turned on, the switch light comes on, but the BOL does not - and no steam is produced.

My understanding, from reading on here and other forums, is that if the BOL stays off then that usually points to the steam thermostat being bad. So I replaced the steam thermostat.

The next most likely problem, again - based on what I've read, is that the steam switch is bad. So I replaced the steam switch.

Still no joy.

I've picked up a multi-meter to test the thermostat, and it is good.

So what next?

I've read that I should test the resistance across the boiler terminals (its 48) - and that it should be about 64. Is this indicative of a problem? If so, what's going on? The boiler is still heating up to water temperature - so I'm confused and frustrated and in need of help.

Any tips or advice would be gratefully received. Thanks.


----------



## El carajillo (Mar 16, 2013)

Remove the connections from the boiler, recheck resistance across the terminals and note. Check resistance between each terminal and the boiler body.

This should give an open circuit reading = 0. If you obtain a reading it is probably the heating element breaking down.

Check all terminal connections for signs of burning / scorching or discoloration, if any are this could be a high resistance.

Mark up terminals with a "sharpie" (marker pen). Systematically disconnect each cable and check resistance (end to end) with your meter, look for high readings, if there are any this will indicate faulty connection or cable.

Try these and report back.

Has the machine been descaled ? recently ?


----------



## Nikko (Aug 20, 2014)

The boiler works for brew water so it is OK

The BOL , brew thermostat and steam thermostat are connected in series, so the steam thermostat is not the culprit

Closing the steam switch by-passes the brew thermostat so if the switch is good then the heater should work. I would check the steam switch again and also that the wiring is correct - wiring diagrams are easy to find


----------



## mpmcgowan (Jul 2, 2016)

Thanks folks - I keep the machine de-scaled pretty regularly (every 3-6 months & I use filtered water) but I'll do it this weekend, if that might help. I've got wiring diagrams, so will double check those & have a go at the checks you've suggested, on Sunday, & report back any findings. Thanks again to you both.


----------



## mpmcgowan (Jul 2, 2016)

I've de-scaled Miss Silvia this morning, left her to cool, unplugged her and done a few tests:

First up, water at the brew head is coming out at about 80oC just as the boiler hits temperature and the BOL goes out. The temp drops to sub 70oC after several seconds of running.

There is no sign of burning/scorching on any of the actual contacts, but all of the plastic connection covers situated directly above the boiler are yellowed and very brittle/broken.

I've checked the wiring of the steam switch and it is all ok.

Resistance across the 2 boiler terminals, using the 200 ohm setting on the multi-meter, is 48.0.

Resistance from the terminals to the boiler body is 1! It's 1 when the meter is resting, and doesn't change at all when I make contact with the terminal/boiler.

I've stopped testing things there, as I have a feeling that may be as much as you need to know.

Thanks again for taking the time to read, respond and share your knowledge.


----------



## Nikko (Aug 20, 2014)

If all the wiring is ok and the steam switch is ok as you report, then your machine should work.

Diagnostics is not about measuring everything in sight, but having an idea how the thing works and checking systematically.

The way you described the problem is that the big light is not coming on when the steam switch is pressed. That suggests that power is not getting to the steam thermostat. Identify the wires involved and WITH THE POWER OFF check that there is continuity in the whole path leading to the steam stat when the steam switch is on. There should be no continuity when the steam switch is off.


----------



## mpmcgowan (Jul 2, 2016)

Thanks Nikko,

I can't say I'm overly confident that I've got my head around what I'm testing - as an end point I need to check continuity to the steam stat, but I'm not certain where I should be starting from.

So here is what I've done:

Individually, I've checked the wire from steam switch to steam stat, from steam stat to BOL & from steam stat to heater element terminal. They all show good continuity (a reading of 00.1).

I've checked the continuity through the steam switch, with the (red & grey/brown) wires disconnected - there is continuity when the switch is on & none when it's off.

So individually, I think each component from steam switch to steam stat is ok.

Then I've tested the continuity from the BOL (Red wire) to the steam stat, via the steam switch - the other red wire from the BOL - which runs to the brew stat, was disconnected so that i was only testing continuity from BOL to steam stat. The result - with the steam switch off, no continuity; with the switch on, continuity - a reading of 00.1

If I'm following what you've said so far, that suggests that the wiring is all ok - unless I've mis-understood, and tested the wrong thing somewhere along the line.


----------



## Nikko (Aug 20, 2014)

So you have checked the switch and downstream of the switch. Now you should ckeck upstream of the switch. The cable to the steam switch will either be from the main switch or the brew stat. If your previous tests are good then the problem has to lie here.


----------



## mpmcgowan (Jul 2, 2016)

I'm at a loss!

I've checked from the input terminal on the main switch, through the switch, to the steam switch, through the steam switch, up to the steam stat, through the steam stat and onto the element terminal - there is continuity all the way from one end to the other (with the loop through the brew stat disconnected). This continuity is broken when either the power switch or steam switch are flipped to the off position.

There is also continuity through the loop between the two stats.


----------



## Nikko (Aug 20, 2014)

I am at a loss too. If you feel confident you could check that you are actually getting voltage onto the steam stat


----------



## El carajillo (Mar 16, 2013)

check the rating / deg on the steam stat, you have been given the correct one / rating, just a thought:confused: Check across the steam stat terminals for resistance ? not high ?


----------



## mpmcgowan (Jul 2, 2016)

I'm really grateful that you are both persisting with this. It must be a little frustrating, wondering if I am reporting back accurately & checking things carefully.

Steam stat checked - and OK in both regards - 140oC & good continuity.

What about the idea that the heating element is breaking down? Is that still a possibility, given what I've said today - or can that be discounted?


----------



## Nikko (Aug 20, 2014)

The heater element is working well for brew water so it should be OK for steam as well.

As said before, the brew and steam stats are connected in series so the steam stat must also be OK.

The steam switch bypasses the brew stat. The BOL does not come on when the steam switch is pressed indicating that there is no voltage to the steam stat.

Check that the wiring against a diagram to ensure nothing's been mixed up. There should be voltage to the steam stat when the steam switch is on


----------



## mpmcgowan (Jul 2, 2016)

Thanks for the wiring diagrams Frank - I've been using that and the other related diagrams on http://www.frcndigital.com/.

I double checked a few things last night & I'm pretty sure that my wiring matches the diagram.

Clutching at straws somewhat, I switched the machine back on late last night.....and hey presto!

Miss Silvia is making steam again - can it just have been a bad connection that I've undone & re-made in the process of checking the wiring?

If that is the case, then you guys guiding me through the rigour of diagnosing the problem has saved the day, and I'm massively grateful!

Thank you both.


----------

