Length of Water Level Sensor - Nuova Simonelli Oscar

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

Postby jrace » Mar 13, 2019, 9:33 pm

I removed my water level sensor and was going to replace it....but the new one is a lot longer:
Image

How long should it be?
--I assume the same length as the original.

My reason fore replacing it is I have had steam issues for over a year now.
It takes a long time to steam milk, first 8ozs taking close to a minute to reach proper temp, next 8ozs taking much longer.
Prior to this it would steam so fast that I had a hard time making micro-foam as it was so quick.

I took it to the only shop around that works on espresso machines, and they said the pressure was tested good, but the steam wand was plugged.
They cleaned it and gave me a bottle of cleaner. Which I have used 3 times since - but no improvement.

It was slightly better but still not as good as before.

Next I descaled it twice (once the way recommended by the descaler), the other as recommended here:
http://www.elektros.it/en/tips-and-tricks.html

Neither has made any change.

Next I removed the water level sensor and sure enough it was filthy. Could not see any bare metal.
I cleaned it and replaced it, but still no improvement with steam power.
I decided to order a replacement sensor...but this one would almost touch the bottom!

Espresso is still great though.

Any ideas?

jyl

Postby jyl » Mar 14, 2019, 1:31 am

I have not done this myself but it seems you can simply cut the metal probe to the desired length. All it does is conduct electricity, so when water level rises to touch the probe tip that closes a circuit which shuts off autofill.

I hunted around and found this ChrisCoffee article that also says you can trim the length of the probe, so I don't think I'm leading you astray here.

https://www.chriscoffee.com/kb_results.asp?ID=10

And here too

https://www.espressoparts.com/auto-fill ... ling-probe

Anyway, that's what I'd do. Get out the cutting tools and cut the probe. But I'd leave it a bit longer than the old one, in case that one was actually too short. Lower water level means more steam volume.

Water needs to completely cover the heating element, though. Or heating element may burn out.
John, Portland OR
Vintage bicycles, Porsche/VW, cooking, old houses.

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plindy

Postby plindy » Mar 14, 2019, 4:03 am

While I have never seen a specification, all the probes have measured were under 3" / 74mm long
with a under .2" / 5.1 mm bend, 1" / 25.5mm from the end
to provide clearance from the heating element

click

maybe the check valve before the steam tap body is broken?

HTH

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civ

Postby civ » Mar 14, 2019, 6:35 am

Hello:
jrace wrote:My reason fore replacing it is I have had steam issues ...

A water level rod has no bearing on any sort of steam issues you could have.
Unless you had a really huge pressure breach, something you'd obviously have noticed it right away.

A water level rod does just one thing: trips on/off the Gicar circuit that will open the inlet valve and turn on the pump (if not directly plumbed in) to fill the boiler. ie: it is nothing but an extension of the ground cable in the Gicar's circuit to the inside of the boiler so it can sense the water level.

The only reason to replace it (actually just the teflon sleeve if available) is if it leaks through the sleeve, something strange unless it has been somehow damaged. The water level sensor in my Cimbali Junior D/1 is 19+ years old and both the teflon sleeve and the stainless rod are in perfect condition.

I'd clean up the original one, put it back in place and (if possible) return the new one.

Cheers,

CIV

jrace

Postby jrace » Mar 14, 2019, 8:34 pm

plindy wrote:While I have never seen a specification, all the probes have measured were under 3" / 74mm long
with a under .2" / 5.1 mm bend, 1" / 25.5mm from the end
to provide clearance from the heating element

click

maybe the check valve before the steam tap body is broken?

HTH


Check valve seems to work normally.

Oddly the original does not have any bend.

civ wrote:Hello:

A water level rod has no bearing on any sort of steam issues you could have.
Unless you had a really huge pressure breach, something you'd obviously have noticed it right away.
I'd clean up the original one, put it back in place and (if possible) return the new one.

Cheers,

CIV


Thanks for the info, I have cleaned and put the original back in.
I am grasping at straws to sort this out and purchased a new sensor just in case.

Still no improvement with steam.
:(

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civ

Postby civ » Mar 14, 2019, 9:37 pm

Hello:
jrace wrote:Thanks for the info ...

You're welcome.

jrace wrote:Still no improvement with steam.


From the looks of it, it seems that the Oscar's boiler is smallish and curiously enough, the spec sheet says nothing of boiler capacity.
In any case, lack of steam pressure means a low boiler temperature which in turn means low brew temperature.

You mention a steam problem but say nothing about how your shots are tasting.
So, how are your shots? Is steam the only issue you are having?

Provided the vacuum valve is working properly and does not leak, steam pressure will build up with the temperature rise inside the boiler which is in turn a product of the element turning on (when the boiler is below the thermostat/pressurestat's set point and off when it reaches that set point and so on.

That said, if you can steam some at first (but not as before) and then much less, you probably have some sort of problem with the pressurestat (for some reason) cutting off at a low pressure.

I see from on-line photos that the Oscar does not come with a boiler pressure gauge.

Once every couple of years and after a thorough clean-up, I check the pressure setting on my Pavoni EP (no pstat or gauge) by sliding one end of a long piece of silicon tubing (the size that will take some effort to slip on to the steam pipe using a little lube) which has a small cheap ~2.0 bar pressure gauge attached on the other end.

This is what I clobbed together about 10 years ago as a temporary thing. =-/
Still works quite well.

Image
ie: steam pipe ->*<- silicone tubing ->*<- 2.0 bar pressure gauge.

You'll figure one out for your Oscar.
Just be sure the tubing attachments to the steam pipe and gauge are firm, use thin zip ties (*) to keep the tubing from slipping off under pressure.

You slip it on the steam pipe when cold and once the boiler is up to temperature, open up the steam valve and check the reading.
It's an easy and inexpensive way to check the pressure at which the boiler is working when idle.

If you are not getting ~1.2 bar min. you'll have to check the piping from the boiler to the pressurestat, it may be clogged.

Cheers,

CIV

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sweaner

Postby sweaner » Mar 14, 2019, 9:47 pm

I am not sure that the water level has "nothing" to do with steam performance.

If the water level is too high there will be less steam produced. The longer probe would be able to allow you to adjust the water level by adjusting the length, I believe.
Scott
LMWDP #248

www.coffeefreek.com

jrace

Postby jrace » Mar 14, 2019, 9:54 pm

civ wrote:You mention a steam problem but say nothing about how your shots are tasting.
So, how are your shots? Is steam the only issue you are having?

Shots are good, but I only drink lattes, so perhaps they could taste better.... I honestly have no frame of reference at this point as the issue has gone on for far too long.

jyl

Postby jyl » Mar 14, 2019, 10:44 pm

On my Elektra the water level is just a little above the heating element, leaving the maximum volume for steam. Since the Oscar is a HX it doesn't need too full of a boiler. And it's boiler is reasonably sized, I'm reading 2.3 liter.

Weak steam would be
- Water level too high (try using the new probe but slide it in the teflon sleeve or cut it so water level is above heating coils)
- Water temperature too cold (pstat adjustment)
- Obstruction between boiler and wand tip (shop said was okay, but if everything else is okay you might take a second look)
- Steam leak (seems you'd have noticed it though)

If you hold a thermometer against the boiler for a while, does it read a nice high temperature, like 225F or similar?
John, Portland OR
Vintage bicycles, Porsche/VW, cooking, old houses.

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civ

Postby civ » Mar 14, 2019, 11:54 pm

Hello:
sweaner wrote:... not sure that the water level has "nothing" to do ...

Seeing that the OP relates that the machine worked perfectly well as it was (with the original probe) until about a year ago and although what you say is 100% correct, I think that in this particular case it does not have anything to do with the problem at hand ie: the lack of steam.

There is something else to consider: the Oscar has no water level sight glass (early models apparently did not have a vacuum breaker either) and this is probably the reason the original probe has the length it has: to protect the element lest a longer (adjustable) probe get pushed down too far, setting the water level below the minimum required to safely cover the element.

IMO, to tinker with the length of the probe without having a permanent water level reading (sight glass) is to ask for a burnt out element on short notice.

That said, it seems the probe worked even with scale (described as filthy by the OP) so I don't think it is what is causing the problem.
If the probe had scale to the extent of looking filthy to the OP, be certain that there's enough scale between the boiler and the pressurestat to keep it from working properly.

Cheers,

CIV