Easy way to check the heater, just put a multimeter on it and see if you have continuity. If the circuit is open, the heater is blown.

erics wrote:You could do one of two things in order of preference:

Unplug machine and move the wires to another set of contacts.

Temporarily attach the wires to a simple light switch.

Sigh....
Moved the set of wires to the middle set of P-Stat contacts.
No joy

Randy G. wrote:No knowledge of that machine, but is sounds similar to a possible false pressure in the boiler from a stuck vacuum breaker valve (if it has one)...? Ayedunno

Doubt this applies to the Oscar as it doesn't have a vacuum breaker valve - one of the Oscar's "cons".
Matter of fact, I have to open the steam valve every morning to release the false pressure to ensure the boiler gets up to proper temp.

HB wrote:Not saying this is a probable cause, but as a cautionary note...

Once a service tech warned me about flushing a boiler too quickly to freshen the water; he explained that it may subject the heating element to too much thermal stress, rupture the ceramic jacket, and short out the heating element.

cannonfodder wrote:Easy way to check the heater, just put a multimeter on it and see if you have continuity. If the circuit is open, the heater is blown.

Dan, Dave-
I truly hope it isn't the heater as it seems a lot to do to replace the heater.
I'm going to take a breather and try checking the heater for continuity tomorrow...
My concern now is assuming the heater checks out ok, is with the GICAR box.
I'm too frustrated right now and am wondering what the F*&%@# I did to cause this - whatever it is. I've descaled 3-4 times previously and never had this happen. Main thing I did different this time was to use red food color. Last problem I had was when I adjusted the brew pressure and got nothing but steam - luckily I had an extra Ulka pump handy and replaced it and everything was well.
Most importantly, I still have my lever machines to use so I can still have my cappuccino tomorrow morning

Did you unplug the level probe to overfill the boiler? Wondering if you could have gotten some spatter inside the machine and simply have a moisture issue on the electronics. My old Isomac would flash all the lights when the water reservoir was empty. There is a pressure switch under a spring loaded tray. If the switch got wet or went bad, it could think you have no water in the reservoir and is not powering up. You could also test that switch with a continuity meter. If you get continuity while the switch is pressed down it is good, if you get nothing with the switch open or closed, you have a bad switch. You could make a jumper wire to connect the two spades on the switch to hot-wire it for testing.

cannonfodder wrote:Did you unplug the level probe to overfill the boiler? Wondering if you could have gotten some spatter inside the machine and simply have a moisture issue on the electronics. My old Isomac would flash all the lights when the water reservoir was empty. ......

I didn't unplug the level probe - what i did was pulled it up a couple of millimeters or so to quasi-overfill the boiler. Once I let the solution sit in the boiler for an hr or so I drained it. Since the Oscar doesn't have a hot water wand, there is a drain plug on the lower left (facing the machine) that I removed, I then removed/loosened the fitting which leads to the steam wand to help vent and tipped the machine on it's left to facilitate draining. Of course when I'm draining everything is off and the machine is unplugged. It's when I plugged it all back in and had it try to auto-refill when the issue started

I do want to thank all for the replies and assistance. I knew I could count on this community for help.
I'm going to shoot off an email and also call Nuova Simonelli in Seattle to see if they can provide assistance and will let everyone know of the outcome.

Update-
I've sent an email to Nuova Simonelli USA and a tech there is assisting me - so far he's provided pretty much the same advice already given here (pstat, level probe, heater continuity)
Good news, bad news
Forgot to mention that I've confirmed the heater itself is ok as the multi-meter reads 9.7 ohms not open
Checked the level probe and water level - both seem ok.
Not sure if the P-Stat is ok - how do I confirm this?
Only thing left in the circuit now is the GICAR box (I think) - I'm hoping NS can provide a little more help with troubleshooting here. I notice the GICAR is ~ $150-200 and if this is what it takes to make the "Grouch" functional, am prepared to get one but I want to make sure it is the GiCAR is the fault before I purchase one as I don't think they are returnable once purchased.

Although I can still use my lever machines (Microcasa and 'picolla) they're not morning friendly like the Oscar. My family misses their morning cappuccino

Not sure if the P-Stat is ok - how do I confirm this?

Firstly, pics on your part would be helpful, especially those of the Gicar box (undressed & both sides). But, to answer your quiz on the pstat, it should have two wires going to it, yes?

With the machine off and unplugged, disconnect those two wires and measure for continuity across those particular pstat terminals. You should have full continuity, resistance = 0. If not, connect the two wires to a simple light switch from your local hardware store and see if this can power up the heating element - just TEMPORARILY.

First - yippee!!! the heater now turns on and the "Grouch" is functional!

I'd like to go ahead and address Eric's questions and comments also and will do another post to let you guys know how this got resolved - quite embarrassing actually.

Eric- When i get a chance I'll post pics of the GICAR box. Requires me to turn the machine upside down and couple of other things. I do believe if you and others can assist with how to probe a GICAR box for certain functionality it will be good for others in the future - I don't need the assist anymore but I do believe it will help others in the future if ever they run into a similar issue. The schematic in the manual gives a glimpse and actually assisted me in following the circuit but didn't allow me to troubleshoot the box itself.

I did check the P-stat for continuity and found it to be ok - just wasn't confident in how to do that but after inspecting it w/o the cover was able to figure it out. It was initially puzzling to me as the reading on my multi-meter kept going up and down but essentially told me that it wasn't open. After examining the P-stat and how it works I now understand why the reading could go up and down as it is a spring loaded device that could move depending on how you probe the contacts.
As far as temporarily attaching it to a light switch - I temporarily attached the two wires together to see if the heater would turn on. Doing this actually clued me in to where to look in terms of the circuit as it didn't help - see my next post for details

So... how did this get fixed?
Well after looking at the schematic and reading the suggestion about hooking up a light switch instead of the P-stat - I connected the two wires together and found out that nothing was happening - the heat light wasn't turning on and water wasn't boiling.

So, I looked at the schematic and just followed the circuit. 1st thing upstream of the P-stat is the heat indicator light. Followed those wires, wiggled them a little, turned on the machine and noticed same behavior. Wiggled the wires a bit with the machine still on and voila!! the heat light turned on for an extended time. Shortly afterwards, i could hear that water was starting to heat up.

Whew!! I was afraid that I had shorted something in the GICAR box while draining the boiler. The drain on the Oscar is positioned away from the GICAR box but if one isn't careful there's a remote possiblity while one tips the machine in the right way to facilitate draining that water could get in the compartment where the GICAR box is in. I didn't think I did this but one has senior moments especially in times of unexpected results that tend to cloud one's memory further.

Again - thanks all for the replies. I hope this can be helpful to others doing their own troubleshooting in the future.