Nuova Simonelli Oscar water automatic refill when brewing

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zhaokyosho
Posts: 11
Joined: 11 years ago

#1: Post by zhaokyosho »

I already bought a Simonelli Oscar, it's a really fantastic espresso machine (updated from delonghi toy machine). but I'm facing an issue on automatic boiler refilling, it some times refill the water suddenly when I'm brewing the coffee! it did confuse me a lot since this action will share a part of water flow and pressure from the pump and resultant in unsteady pressure and flow. I was not using the steam when brewing the espresso so I can't understand why the boiler need to be refilled. it's not often but really can't be predicted. does any one know if this is normal or there's a defect with my Oscar?

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plindy
Posts: 157
Joined: 13 years ago

#2: Post by plindy »

looking for more information :

new machine
or just new to you

early model , small Pstat
or late model , large Pstat

water in reservoir
or direct connect

are you mechanically challenged
or mechanically / electrically adventurous

As described it does not sound normal

skipping ahead
no leaks
no burnt or frayed wires
clean boiler level probe

1st guess the one way valve above the HX entrance has broken and is in the 3way valve , look for green plastic bits in the entrance hole or first chamber of the 3 way.
This would cause intermittent unsteady flow and pressure from the group head
2nd guess an intermittent condition causing both the 2 and 3 way valve to be open at the same time

HTH
Gluck
pete

acarter
Posts: 6
Joined: 12 years ago

#3: Post by acarter »

Hi @plindy,

I have low flow from my group head so I pulled three way valve apart and there was indeed a little green piece (like an icing sprinkle) inside the chamber.

If I remove this part and reassemble, which is the one way valve that I need to replace? Is the green bit critical (I'm assuming so).

Thanks for getting me this far!

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plindy
Posts: 157
Joined: 13 years ago

#4: Post by plindy »

pic and links
read'um all

was in Ferndale Wa Tuesday morning

part# 01000090 retaining valve
02290020 AN25 heating element O-ring

the questions are : :lol:
how good do you want to be at taking apart you Oscar ?
the one piece found in the 3way might be the only one floating around...
do you feel lucky ? :roll:

happyhollowdaze

G'luck

acarter
Posts: 6
Joined: 12 years ago

#5: Post by acarter »

Hi Pete,

Definitely the retaining valve. The green bit I found is probably the centre part of the valve. No leaks inside the machine so I'm hoping this should be sufficient.

Thanks for your help and best for 2014.

Cmmts
Posts: 19
Joined: 11 years ago

#6: Post by Cmmts »

I'd say this is normal behavior...