So I have a direct connect Oscar version from 07/2015 with the sirai pstat. When the machine turns on the heating element light turns on for about 2-3 seconds then turns off and the low water level light turns on. After some research here and elektros.it most advice seems to be for the pour over variety. Just for sanity I pull the electronic unit, aka brain box, and the pin 1 does pull to ground and pin 3 as expected. What other sensors and components feed input into the unit that triggers this. Since it disables the heating element and water pump.

Thanks for any and all help

So I'm not familiar with your machine but I am familiar with troubleshooting. Probably the low level situation turns your heating element off. First thing to do is check low level wiring/sensor. With a multi meter check the sensor for continuity. It should change state whether full of water or not. If it doesn't change... bad sensor, if it does change state u need to go look at the wiring diagram.
If u want to check the status of the rest of the machine, consider tricking the sensor wiring temporary in order to see if everything else works. This could cause a melt down if the boiler has no water, it is only a test scenario

Thanks for the response. But the diagram is on the last page here->http://www.nuovadistribution.com/images ... Manual.pdf


Has the wire diagram. So it doesn't actually have a low level sensor it is just ran to ground. I verified that by test the resistance of pins 1 and 3. They totally ring out to 0.

If it has a low level light it has a low level sensor of some type. That wiring diagram does not explain enough for me to understand everything going on. I will hazard a guess that there are 2 possibilities. 1. the water is low a contact closes and shunts to ground, the control unit then identifies "no water" and turns off the heating element. Or 2. when water is low a normally closed contact opens, losing the path to ground, the control unit etc etc. So if u disable the interference of the sensor either by disconnecting it or bridging it (depending on the sensor type) u will be able to test this hypothesis.

I have a little insomnia so went a little deeper. You don't mention what year your Oscar is, but fortunately they appear to be similar if not exactly the same re wiring and hydraulics 2001-2010
http://www.nsstorage.it/download.php?ui ... EwLnBkZg==

This image (the Oscar 2006 and 2010 seems to have the same schematic) has the sensor or something called LE . When you trace the pin outs from the control units to the "senso" LE what exactly do you see?
Looking at the hydraulic plan (again 2001 and later model appear the same)


Either item 1 or 6 (or both together are giving the control unit the info it needs Re water level/water in tank.
The wiring schematics above nor the hydraulic image still do not reveal exactly what they do but should aid you in finding their location and then you can analyze how they work.
My earlier analysis re level sensor bypass still stands with the caveat that the unit is using microprocessors and before you bridge or ground anything you need to understand exactly what / how the level sensor works.
Also because the unit has microprocessors a more detailed electronic diagram would help, and there is also the possibility that the main controller has a fault, and that would be harder to diagnose. For now I would (using a multimeter etc..) try to work out how the unit senses the water level (there are a variety of ways, item 1 could be it and my money is on 1, because it would stop the pump from ever running dry , item 6 is too far down the line, but probably participates somehow.
In computer controlled systems (you control box is basically a little computer from what I can see) it is quite often the mechanical interface items (sensors etc) that fail as they are the only moving /quasi moving pieces in the control sequence.
As I said before I do not know anything about this unit, it is going to be more complicated than an electro/magnetic style machine (did I mention my home machine is a commercial lever? lovely clicks of solenoids and contact points opening valves and turning on heating elements) you barely need a multimeter, just watched the contact points to see what is up.... I digress, your unit is not that complicated, it is not clear if you have opened up the hood on this yet, a physical examination of the wiring from breakage etc is a good place to start, and from there observing how the various sensors allow /disallow outage etc. Item 6 hydraulic which seems to correspond with pin out 2 in the electric diagram is an example. I would guess that when the unit has high enough water in it the sensor probe goes to ground , which then tells the unit ok water level high enough, so fooling that one would be simple, The LE until in the electrical diagram is less clear, and as it has a number of wires may be more complicated to analyze.
Cheers and good luck, the truth is out there.

He has the plumbed in version. On the tank version of the Oscar, the tank plugs into a port in the machine and drains through the bottom to that port. That port has electrodes that sense whether there is water in it. It sounds like on the plumbed in version, they disable this sensor via the jumper.

I would guess that your gicar has a problem. But you might want to verify the other connections.

Also, I think that the Oscar pump will activate for a short while when it first turns on if you press the button. Perhaps try that?

Brian

Budged over heated capacitor in brain?


new one looks like

Thank you for the reply, can someone test pin1/3 and tell me what voltage is meant to be on the line? I am guessing Plindy is right that it is a cap/transistor that has failed and the proper voltage isn't getting sent across. While powered on, I am getting 0V on both 1/3 pins.

Thanks for any and all info.

plindy wrote:Budged over heated capacitor in brain?

<image>
new one looks like

So I have not figured out what is wrong with the board, that is next. But I did hack it enough to get the machine functioning. I managed to find many other threads that seem to go dark on this topic and figure people either just purchase new electronics units or sell the machine as parts.

I do not recommend this to others but, if you also don't have the ability to figure out the board here is my hacks

I jumped the pins on RL1 to enable the pump and 2-way valve, this leaves both paths open but one path is just the annoying light


Next to get the heating element to work I created a branch off the main switch, one going to the heating element that I disconnected from pin 5 and the second going back to the original location on the gicar electronics unit pin 10


And everything lit up and seem to be functioning, hurrah for getting a 100$ ebay find to work.


Sorry about the crappy images. This is mostly a way to verify the boiler and machine worked fully before I dedicate time to strip it down and clean it up, and start doing all the other oscar mods, which will likely include replacing the electronic unit.