Nuova Simonelli Appia II doesn't auto refill.

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

#1: Post by Coreytownsend »

Greetings from Seattle!
We are towards the end of our coffee trailer build and our used machine (Nuova Simonelli Appia II) doesn't auto refill.
Using google as my friend I've now determined that the pump does work. The water level probe has the single red wire attached to it to which I have removed and the pump kicks on. Attach it and it turns off.
I removed the probe expecting it to be calcified etc but it's brand new. It is also completely straight which leads me to believe the person we purchased it from replaced it as figuring it was the issue.
I believe it's supposed to be bent to be at a certain angle and length? I'm at a bit of a loss as to where to go next and any help would be extremely appreciated



#2: Post by JRising »

Its length needs to be such that the water level will completely submerge the element. Bend doesn't matter. Finding out where it's shorted to ground will be neccessary.

If removing the wire from the probe works to make the machine try to autofill, then the short to ground is right up against the probe. A new probe/sleeve/fitting assembly should solve it.

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#3: Post by Coreytownsend (original poster) »

Thank you for the reply! How far into the boiler does the probe need to go?

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#4: Post by Psyd » replying to Coreytownsend »

The probe needs to go into the boiler enough to sense when the water is covering the heating element. It's main job is to keep the heating element submerged. Keeping enough water in there to heat the HE and make tea are secondary and tertiary at best. setting the level of the water lets you decide (to some extent) how much steam you have available. A high sensor increases the steam pressure and lowers the volume of the steam, and high water level means that boiling water can at wetness to the outgoing steam. Lower sensor will give you more steam volume, which means less pressure but drier steam. Anything above the midline is pretty safe, up to about a quarter. Mine is somewhere in between (call it, two-thirds full) because I steam something like an ounce or an once and a half of milk at a time. With my Appia, I've got the probe bent 90 right inside the boiler, and I can turn it from straight down to a 45 to adjust water height in the boiler.
An easy test to see if your level probe is working is to take a voltage meter set to diode check (or resistance) and see if it beeps (or shows near 1 ohm or less) between mounting hardware and the connector on the probe, it's probably shorted. Or your boiler is really full. Let it cool, drain it a bit, and re-install the probe bent downward as I described. You should be able to get the autofill to kick in by turning the probe in its housing.
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