8531 /Burner Issue UPDATE--Photos ( Fixed!)

[BFL13]

With the furnace running, where do you put the pos and neg leads of the meter? Or can you do it at the Tstat inside with the furnace on?

I want the 12v to the board, not the voltages the board puts out to the various components. eg,I got 10.67 at the gizmo on the right of the fan casing and some metal nearby, but I don't know if that is the loaded 12v with the furnace running or what.

Thanks

[MT_BOB]

Good job,and good luck. Usually those terminals are crimped and spot welded,I do not think solder would be something to try.

[BFL13]

I got it working.

First I found the spare three-prong thing I couldn't find yesterday, which took care of that connector I broke on the other one. (I cancelled my Amazon order for a new one)

I swapped out the relay with the spare and doing that found the short red wire to the top of it (the one that was there before) from the bottom of the circuit breaker was loose on its top connection at the relay. So now the voltage at the top of the relay connection is the same as at the circuit breaker.

That voltage seems low to me compared with battery voltage and the video guys seem to get closer to the battery voltage on theirs. Whatever, the furnace fires right up at the start and keeps running. I won't know till another time if it keeps running all the way, but at least we can go camping now.

EDIT: It ran the RV temp up from 9C to 15C Tstat setting and stopped without cutting in and out. Looking good!

Thanks everyone for all the excellent advice and info working with this. 🙂

[BFL13]

This the before photo of the red wire going on its sparker thing via a spade terminal on the end. At some point today that broke off so there was no place to slide on the wire terminal for it.

I widened the wire terminal so it would wrap around the end of the probe end and squeezed it on tight.

If that didn't work that might be why there is a click but no spark down at the sparker end above the screen? Thinking of MT BOB's idea there.

That spade that broke off was like it had been bent back and forth too many times and I bent it one too many times. If it has been sort of just hanging there since who knows when (years?) perhaps that would explain some of this?

OTOH, once it sparks and it fires the gas, does it ever spark again until the next cycle? I was having the burner cut out and then spark re-light several times during a cycle until the last one that got the Tstat to shut it off. After the RV cooled down, it would start again by Tstat and same story on and off till the RV got back to Tstat shut off.

My new three prong part should take care of that red wire connection if that is now too bad to work right, but that leaves maybe a ground issue or any of those other things on the list it might be.

I could try to solder that on where it is squeezed on, but not sure it would "take" or just be a cold solder with that metal.

[enblethen]

The white thing is the reset button. Yes, it is a ten amp.

[BFL13]

I have another relay I can try that was on the 111 or 11, not sure now which is on the one in use. I see how that goes looking at this

https://www.youtube.com/watch?v=QxDOw4LAWyo

I can check voltages again after swapping relays. The "CB" has a white thing on the end that says 10A and seems to screw in so it looks like it is a fuse, don't know. I have a spare one of those too.

Meanwhile I ordered the three-prong part on spec, should have it in a week or two.

I'll fiddle with it all some more tomorrow and report back 🙂

I checked out the limit switch last time and it was not that. I have the right size limit switch in there, as they have two with different limits.

[MT_BOB]

If you hear the click,that is the spark going somewhere. Possibly damaged the big wire, or cracked the porcelain. When you pull it out to test it, the burner housing must be touching another metal part of the furnace,or a jumper wire used, to have a ground.If mot, the spark can jump down at the control board.
The snap switch is the high limit safety switch, they are model different.

PS The guy in the video is wrong(rare for him,he is good), it is not 12 volts on the big wire, it is several thousand. The igniter system is basically a coil and spark plug.

[enblethen]

From earlier post:
Battery voltage start- 12.59
Battery voltage furnace running- 12.50
Voltage at furnace CB- 11.34
Voltage at thing to the right-10.93

I would try to find from the Circuit breaker 11.34 to the Time delay relay 10.93 voltage drop.

[BFL13]

enblethen wrote:
Did you find where you were loosing the nearly half of volt in the 12 volt portion?

No. Do you mean between the 10A ? fuse?/CB on the left and the timer on the right?

EDIT--this guy says if you smell gas and hear a click the problem is on the burner side. I will get a new three-prong thing and try that. I must have done something today to make it worse than it was so now it doesn't work at all!

https://www.youtube.com/watch?v=AB69oqtSiwc

[enblethen]

Did you find where you were loosing the nearly half of volt in the 12 volt portion?

[BFL13]

Did the clean ups, bent the three prongs down a bit, got it all back together, and now all I get is the fan and some clicks, smell gas, no flame.

Pulled it out with no gas line, all wires connected and turned on Tstat, still runs with fan and then clicks, but no spark seen on the sparker ends.

Tried my other boards I thought were not working right before and same thing. The board that was working till today (except for the cutting in and out business) was at least getting the burner to light after the click. Not now.

That "rusty" plate the prongs are on is actually copper that shines up so it is not as bad as it looks in the photo.

No idea what to try next!

Maybe I should get that three-prong part from Amazon since it is not costly. I could get a new board but I am not convinced that is the problem yet.

[enblethen]

Look at the circuit board for your water heater, Many are the same as furnace. If they are swap them out to see if problem changes.

[BFL13]

Thanks all, for the great help!

What is the "snap switch"? I might have a spare I can swap in.

[MT_BOB]

The gasket is to keep fumes out of your camper.

[MT_BOB]

Yes,the ground for the igniter is through the screws, make sure there is a clean connection.