Hello everyone,

This evening when working on my Elektra (steam valve gasket service), I turned on the machine before putting everything back together. There was an immediate pop/spark and shutdown: the autofill light leads were touching, so as one would expect when connecting 120VAC to ground, the breaker tripped (thanks, safety!). Once I reset everything, the machine will no longer autofill, and the symptoms are confusing the heck out of me. Here are the facts:

- Motor runs, attempting to autofill, but the boiler fill solenoid does not open
- I can get the motor to stop by grounding the wire to the boiler level probe
- The autofill solenoid does not open and its light does not turn on
- I am reading 160 ohms across the fill solenoid
- When the machine is on, I read 10Vac across the solenoid
- When the machine is on, I read 120Vac between a solenoid terminal and ground
- There is 0 to 1 ohm continuity between the solenoid and the corresponding terminal of the light
- There is 0 to 1 ohm continuity between the motor and corresponding terminal of the fill solenoid

My conclusions are:

- If the motor is running and I can get it to stop, the Gicar box is not completely blown
- The fill solenoid (and its light) are on a separate circuit in the Gicar box, which I must have blown
- All of the readings look right for the coil and corresponding connections, so I should be able to power the solenoid using a solid state relay and some arduino test code

Based on my description, did I blow up the Gicar box? Is the root cause of my problem still unclear, and are there any other measurements that I can take? Is it time to re-implement the gicar box using my arduino?

Thanks!

You likely did blow up the gicar.
Arduino is way overkill for a simple sensor logic with relay.
Have you considered cracking open the Gicar and seeing if you've blown something obvious? Sounds like you're not afraid of a little solder.

If nothing else, analyzing the circuit would give interesting insights towards homebrewing a replacement.

Yes, I'll crack it open this evening. You're right, I'm not afraid of a bit of solder. Thanks!

The arduino, in this case, is less overkill than it might be otherwise, as I'm using it as a PID controller, and it definitely has enough spare IOs to do autofill.

Another option that I will look into is using the motor end of the autofill circuit to activate the solenoid (if that's how this works) by splicing the solenoid leads into the motor leads...

...wait, then the autofill solenoid would open every time I run the pump, even for a shot. Even if the motor has a separate output on the Gicar, wiring the solenoid in there will still power it on any time the pump circuit is turned on.

As for analyzing the circuit, the box itself has a circuit diagram on a sticker, showing a BJT (likely for sensing the water level) and a few switches (probably turning the solenoid and motor on). At the very least, this is a good starting point. Maybe this points to me blowing up a relay?

Why not simply test the solenoid with a lamp cord and a couple of female spades?

The relay which TYPICALLY powers the pump & solenoid simultaneously during autofill events is simply a DPST (double-pole, single throw) device powered by ~18 volts courtesy of a neighboring transformer.

Eric, for this test, are you suggesting that I connect the solenoid directly to a 120V wall jack to see if it opens?

Thanks!

Yes.

Either in or out of the machine. Keep in mind that if you disassemble it and test in that condition, the plunger WILL TYPICALLY NOT pull down from its disassembled state because of the lesser magnetic field. Screwing the barrel back into the valve body certainly pushes the piston down to a more "magnetic field friendly" position.

Thanks - I'll try to cut open a power cord and do that tonight.

Going back to what you said about the DPST output: if I determine that this is a problem with the Gicar, does this mean that I can indeed splice the solenoid wire into the motor wire without affecting any other functions (or activating the solenoid any time the motor runs)?

No - because as you said before, (then) any time the pump motor gets power, the solenoid would get power. The solenoid is TYPICALLY powered by a single red lead from the Gicar - even if I have the colors screwed up, it should be "duck soup" to trace that particulat wire.

I don't have any different colored wires - it's all up to me and a multimeter to figure it out (which can get confusing, but not impossible, given the low resistance AC components and highly shared nodes!).

Recent, somewhat obvious epiphany: the zero ohm connection between the motor and fill solenoid must be ground!

Phew! Plugging the solenoid directly into line voltage gave a good healthy THUNK along with the faint sound of line-pressure water filling the boiler.

Next step: open the gicar box. At least I know that I can manually fill the machine if necessary.