# Oscar I - loud humming noise whenever it's on



## bclarke (Jul 12, 2015)

Hi all

I recently bought a Nuova Simonelli Oscar (~5yrs old) from a forum member. Was couriered up to me (extremely well packed) and worked perfectly for the two weeks. I then started geting the low water light turning on despite having filled up the tank. Looked online and this appears to be a relatively common issue with this machine. I tried the suggested fixes (turning machine on/off with pump on, reseating the water tank, changing the water) which didn't work immediately but after ~48 hrs the machine was working perfectly again.

Then on Monday (about 3 days after above issues resolved) when I turned on the machine it started making a loud humming noise. This is present everytime I turn it on. I've avoided using it in case it damages something internally but did let it heat up once and it worked as normal, making a good espresso. I'm really not electrically or mechanically minded but took the top of the case off and couldn't figure out where the noise is coming from/see anything obviously wrong. I've uploaded a video to youtube which just shows me switching the machine on and pressing the brew button: 




Realise probably not easy to diagnose without seeing the machine but any ideas? I'm living in Edinburgh - any recommendations who I can take it to to get looked at?


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## DavecUK (Aug 6, 2013)

That noise is the vibration pump running. It's trying to run because it thinks the boiler needs filling. This can be because.



It really does need filling and will quickly stop (I would say perhaps you pulled a large amount of hot water from the machine then switched it off last use, but it doesn't have a hot water tap, or at least they never used to). So you could leave it and see if water comes pissing out the top of the vacuum breaker which it will do if cold.


There is a boiler leak and there is water under the machine


There is a fault in the autofill box electronics


*The auto fill probe wire has become disconnected, or there is a bad connection*


*The probe is badly scaled up*


Bold is most likely and cheapest to fix (although descaling an Oscar is a PITA) , Italics is second most likely and more expensive, the other 2 are remote possibilities.


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## bclarke (Jul 12, 2015)

DavecUK said:


> That noise is the vibration pump running. It's trying to run because it thinks the boiler needs filling. This can be because.
> 
> 
> 
> ...


 Thanks Dave

I left the machine in for 15 min to see if it would heat up normally (which it did and made a decent espresso) and the pump continued the whole time with no water out the vaccuum breaker. And no water leaking under the machine so looks like top two options are unlikely.

I'm not particularly good with electrics and worry I would just do more damage if I go poking about myself so have contacted someone after a Google search. Anyone got anyone they would recommend around Edinburgh if that doesn't work out? I have used Caffeine Fix in the past (who were really excellent) but they indicated they prefer to avoid getting involved with domestic machines.


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## DavecUK (Aug 6, 2013)

Could well be the auto fill box then...


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