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Date: 28 Feb 2007 12:05:21
From:
Subject: Oscar won't heat -- HELP
The heating element on my Nuova Simonelli Oscar won't turn on,
can someone please help me pinpoint the problem?

Some background: I bought the Oscar used about 2 months ago,
it brewed great espresso but the steam wand was unuseable --
the steam SMELLED. Not sure exactly what the smell was,
but it easily transferred to the milk whenever I tried frothing.

So ... I decided to dismantle the entire boiler and
HX pipes, and soak them in citric acid:

http://img230.imageshack.us/img230/6614/descale4hi9.jpg

The good news -- after putting it back together, the
boiler water is now very drinkable. No more smell.
And the boiler is nice and shiny.

The bad news -- now the heating element won't turn on.
No heat whatsoever. No heating light indicator either.
The pump works fine, I have no problem pumping cold
water through the group head.

Anyone have any ideas? I have a few theories:

(a) Somehow the thermostat was damaged (even though
it was removed before soaking)

(b) Somehow the pressurestat was damaged (even though
I tried to keep it dry during the soak, see picture)

(c) Somehow the brain box got wet (there were a few
leaks before I tightened all connections properly)

(d) Somehow the heating element itself was damaged

Basically I am looking for some help -- how do I troubleshoot?

Is it OK to bypass the thermostat (or pressurestat)
with a jumper to see if that is the problem?

Thanks

John





 
Date: 09 Jun 2007 07:21:28
From: John B
Subject: Re: Oscar won't heat -- HELP
If you only want to *flush* the boiler, you can use a trick involving
the autofill sensor... remove the sensor wire and the autofill will
pump water through the steam wand. If you really want to *drain* it
instead, there is a drain plug near the bottom... open the plug, open
something else (like autofill sensor or steam tap) in the boiler to
let in some air, then hold the machine upside down over the sink. A
little awkward but not too hard.

Both techniques are discussed in more detail here:

http://groups.google.com/group/alt.coffee/browse_frm/thread/e04d9e286b268d49/

John

On Jun 9, 2:49 pm, spresso<pra...@hotmail.com > wrote:
> Hey guys.
>
> HOw in the heck do you drain the boiler??
>
> I took the top off and have no idea where to go from there?
>
> Am i supposed to remove all the connections? and pull
>
> the boiler out like you did?
>
> ugh.
>
> I've actually hit a situation where everything works amazing
>
> but my temps at the grouphead are only 160F. I got 190F once
>
> but that was after leaving it on all night and then doing one
>
> blind pull. That doesn't make sense.
>
> cheers
>



 
Date: 02 Mar 2007 07:54:16
From:
Subject: Re: Oscar won't heat -- HELP

> Greand impurities in the water become concentrated. In the annual tune-up
> you should drain the boiler and flush to avoid this problem.

Will do, I will be glad to never smell that smell again.


> There is no thermostat on an Oscar. There is a shut-off that works if
> the temperature of the boiler gets too high. it's the one with the

I wondered about that, I saw the wiring diagram and it showed a
thermostat, but wasn't sure why the Oscar needed one given that
it has a pstat.

> terminals of the pstat (by the way did you reconnect the terminals
> correctly - wires to top and bottom and the middle one empty?)

Bingo! I had miswired the pstat. Jack you should send me a bill,
you successfully diagnosed my problem sight unseen. I thought
I was very careful to label all of the wires when disconnecting,
but in fact I mislabeled one. Now Oscar is back in business,
thanks a million.

John



 
Date: 01 Mar 2007 05:38:36
From:
Subject: Re: Oscar won't heat -- HELP
Great feedback and advice, thanks, now I have something constructive
to do! I'll try each of your suggestions and let you know what
happens.

About the out-of-water indicator, I didn't mention it,
but the light does not come on. And I was able to run
the pump, so I think we can rule out that sensor.

John



 
Date: 28 Feb 2007 18:12:19
From: Jack Denver
Subject: Re: Oscar won't heat -- HELP
Sort answer - try pushing in the reset button on the overtemp thermostat.

Longer answer - with the machine unplugged, you need to test continuity with
a continuity tester or ohmmeter. There should be continuity across (1) the
terminals of the pstat (by the way did you reconnect the terminals
correctly - wires to top and bottom and the middle one empty?) (2) the
terminals on the overtemp thermostat and (3) the terminals of the heating
element (this should show some resistance). Lastly, if the heating element
shows continuity to ground (the body of the boiler) it is fried.



<jb130@mail.gatech.edu > wrote in message
news:1172693121.195270.148590@v33g2000cwv.googlegroups.com...
> The heating element on my Nuova Simonelli Oscar won't turn on,
> can someone please help me pinpoint the problem?
>
> Some background: I bought the Oscar used about 2 months ago,
> it brewed great espresso but the steam wand was unuseable --
> the steam SMELLED. Not sure exactly what the smell was,
> but it easily transferred to the milk whenever I tried frothing.
>
> So ... I decided to dismantle the entire boiler and
> HX pipes, and soak them in citric acid:
>
> http://img230.imageshack.us/img230/6614/descale4hi9.jpg
>
> The good news -- after putting it back together, the
> boiler water is now very drinkable. No more smell.
> And the boiler is nice and shiny.
>
> The bad news -- now the heating element won't turn on.
> No heat whatsoever. No heating light indicator either.
> The pump works fine, I have no problem pumping cold
> water through the group head.
>
> Anyone have any ideas? I have a few theories:
>
> (a) Somehow the thermostat was damaged (even though
> it was removed before soaking)
>
> (b) Somehow the pressurestat was damaged (even though
> I tried to keep it dry during the soak, see picture)
>
> (c) Somehow the brain box got wet (there were a few
> leaks before I tightened all connections properly)
>
> (d) Somehow the heating element itself was damaged
>
> Basically I am looking for some help -- how do I troubleshoot?
>
> Is it OK to bypass the thermostat (or pressurestat)
> with a jumper to see if that is the problem?
>
> Thanks
>
> John
>
>




 
Date: 28 Feb 2007 13:31:31
From: chardinej
Subject: Re: Oscar won't heat -- HELP
On Feb 28, 4:05 pm, j...@mail.gatech.edu wrote:
> The heating element on my Nuova Simonelli Oscar won't turn on,
> can someone please help me pinpoint the problem?
>
> Some background: I bought the Oscar used about 2 months ago,
> it brewed great espresso but the steam wand was unuseable --
> the steam SMELLED. Not sure exactly what the smell was,
> but it easily transferred to the milk whenever I tried frothing.
>
> So ... I decided to dismantle the entire boiler and
> HX pipes, and soak them in citric acid:
>
> http://img230.imageshack.us/img230/6614/descale4hi9.jpg
>
> The good news -- after putting it back together, the
> boiler water is now very drinkable. No more smell.
> And the boiler is nice and shiny.
>
> The bad news -- now the heating element won't turn on.
> No heat whatsoever. No heating light indicator either.
> The pump works fine, I have no problem pumping cold
> water through the group head.
>
> Anyone have any ideas? I have a few theories:
>
> (a) Somehow the thermostat was damaged (even though
> it was removed before soaking)
>
> (b) Somehow the pressurestat was damaged (even though
> I tried to keep it dry during the soak, see picture)
>
> (c) Somehow the brain box got wet (there were a few
> leaks before I tightened all connections properly)
>
> (d) Somehow the heating element itself was damaged
>
> Basically I am looking for some help -- how do I troubleshoot?
>
> Is it OK to bypass the thermostat (or pressurestat)
> with a jumper to see if that is the problem?
>
> Thanks
>
> John

The smell comes from the fact that there is no routine way to exchange
the boiler water with fresh on an Oscar. Over the course of useage you
evapourate water from the boiler to make steam and all the minerals
and impurities in the water become concentrated. In the annual tune-up
you should drain the boiler and flush to avoid this problem.

There is no thermostat on an Oscar. There is a shut-off that works if
the temperature of the boiler gets too high. it's the one with the
little reset nipple on it. Maybe the nipple was set to off when you
removed the tank- try resetting it by pulling or pushing it (don't
know which as mine has never gone off). I suspect that if the
pressurestat was damaged by water it would be never shut off the heat
rather than never call for it. You could check the heating element by
checking the resistance across the connections with an ohmmeter
(unplug the machine before you do this). The heating element should
register a resistance but should not be "open" (infinite resistance).
The electronic box could be burned out if it got wet but it is pretty
well protected in its own compartment. Remove it, remove the cover
carefully and dry out. On the bottom of the machine there is a
connector block. I would remove each one and clean/dry and reconnect.
You did not mention if the "water-out" light is on (maybe the bulb is
blown??). If the machine detects water out, the element will not
work.

Let me know how you get on.

John (another Oscar owner who has performed open-heart surgery on his
machine)