Different Sparker Types Question

[BFL13]

I have three sparker types in the sig MH that I am curious about:

1. The furnace has three prongs
A. igniter-red wire
B. sensor?-black wire
C. ground rod in the middle. Grounds to frame

It sparks between the igniter and the ground rod

2. The fridge has two prongs:
A. igniter
B. sensor

It sparks between the igniter and the sensor

3. The water heater has two prongs:
A. igniter
B. ground rod

It sparks between those two

So what/why the differences? Thanks.

(I was looking to swap a spare furnace set I have handy or a spare water heater set I have handy for the one in the fridge that has been acting up, but they are not the same for how they work apparently. They don't fit either, but I was going to jury rig it.

I was able to get them to spark from the fridge's ignition wires though, which is how I saw the way they spark.)

[BFL13]

Thanks for the follow-up on that.

Newsflash! After a major all-day episode taking apart half the MH (it seemed like), I got the S630 out and the Norcold 641.3R in, with the help of Number 1 son for the heavy lifting. MH door with its frame had to come out for one thing. 😞

What a pleasure to have a modern fridge (from 2002 according to its certification) like we had in the 2003 5er. No more constant "issues" I hope . This 641 is running perfectly.

Thanks to you and the others who helped me keep the 1991 S630 going for the last two years--but enough is enough!

[Chris_Bryant]

The electrodes are just a wire in the fire electrically, the difference being position.

[BFL13]

Thanks. Are the electrodes the same electrically? The igniter has that angle at the tip, but could it act as the sensor (swap wires to it) if you had another ignitor?

I can't just replace the electrodes on the fridge because they are rusted in.

I have a corroded fridge sensor electrode that only works sometimes, but the igniter is ok. One jury rig might be to switch the wires so the ignitor gets the black wire and becomes the sensor, while the water heater set that has only the ignitor and a ground rod (remove?) is the new ignitor. I can physically get that in place messing with the brackets.

Using the furnace set is a problem physically, where the prongs are so long, but it does have both electrodes.

I have a line on a used Norcold that might replace the whole fridge, so I am looking at my options.

EDIT--I got a Norcold 641.3 so next episode is to install that.

Thanks.

[Chris_Bryant]

The older boards used a separate flame sense electrode, also known as remote sensing. Now they sense the flame through the spark gap, aka local sensing. You can sub a local sense board for remote, but not vice versa.