Strange fuse blowing issue with St. Croix York insert

[Clay H]

So I am having an issue. My igniter burned out at the end of last season, I had been buying aftermarket igniters from Grainger but they only last about 1 season and I had a spare igniter to use before I order an OEM part. So I installed the cheap igniter, begin a test fire and all seems fine until after about 10 min. the power to the stove went off. I put the fire out, unplugged the stove and checked the fuse. It was toasted so I replace that and go to do another test burn and the igniter never got hot, no fire, just pellets piling up in the burn pot. I pull the igniter and OHM it and its toast.
So I order a new OEM from an online dealer. Installed it and I got the exact same results as above, fuse blew after 10 min and igniter was toast.
Called St. Croix tech support and they guy sounded very educated but he had no idea and of course over the phone made finding an answer very difficult. He told me to look for a dead short in the wiring which I did but it just doesnt make sense.
One thing I failed to mention, after it didnt lite the second time, I hand lit the stove and ran it for about 2 hours with no hiccups. So something points to the igniter blowing my fuse it seems. Any tech guys here wanna offer their $0.02?
I also talked to the service guy at the store where I originally purchased the stove 13 years ago. He was drawing a blank as well but he said "we'll get this figured out somehow"...lol.

 

[heat seeker]

Make sure the passage around and to the ignitor is clear of ash. Anything blocking the airflow will let the ignitor overheat.

 

[Clay H]

Make sure the passage around and to the ignitor is clear of ash. Anything blocking the airflow will let the ignitor overheat.

Yes the tech I talked to mentioned that and I looked inside with a flashlight and it was indeed clear. I think maybe I need to hook my VOM to the 2 leads that power the ignighter and see how long its energized - after hand lighting the pellets. Maybe its staying on when it should not be on?

 

[jzm2cc]

I've been running my used Prescott EXP for 2 years, still on same igniter so your condition is strange. Can't say enough good things about my ole stove.

1. Are you sure the multi-meter is able to read resistance? Worth checking generic and OEM igniters with a known good meter. Usually they have 40 to 50 ohms when good. Also wonder if your aftermarket igniter has lower resistance, i.e. caused too much current draw.

2. There is a possible short circuit to igniter if it pops fuse when hooked up but runs fine when unplugged and lit manually. A voltage check across both igniter leads would be helpful. Could also do resistance checks on hot lead to igniter WITH STOVE UNPLUGGED. Something in the igniter circuit is probably drawing too much current, thus blowing fuse.

3. Assuming the igniters are burned up, i kind of doubt it would fry within a few minutes but i could be wrong. You've already verified the area around igniter is clean.

 

[heat seeker]

When you say the ignitor is toast - is it shorted, or open?

The ignitor in my used stove lasted 5 years, so that's typical, I assume. You may have a good point in that yours is staying on all the time. That could be caused by a shorted triac or stuck relay on the control board. That would certainly shorten its life, although causing a fuse to blow, I don't know.

I'd also go over every inch of the wires that feed the ignitor. One could be pinched, causing enough of a short to take out the fuse, but not right away.

 

[Clay H]

I've been running my used Prescott EXP for 2 years, still on same igniter so your condition is strange. Can't say enough good things about my ole stove.

1. Are you sure the multi-meter is able to read resistance? Worth checking generic and OEM igniters with a known good meter. Usually they have 40 to 50 ohms when good. Also wonder if your aftermarket igniter has lower resistance, i.e. caused too much current draw.
My VOM is good, yes.
2. There is a possible short circuit to igniter if it pops fuse when hooked up but runs fine when unplugged and lit manually. A voltage check across both igniter leads would be helpful. Could also do resistance checks on hot lead to igniter WITH STOVE UNPLUGGED. Something in the igniter circuit is probably drawing too much current, thus blowing fuse.
I'll check that.
3. Assuming the igniters are burned up, i kind of doubt it would fry within a few minutes but i could be wrong. You've already verified the area around igniter is clean.

Thanks for the suggestions.

 

[Clay H]

When you say the ignitor is toast - is it shorted, or open?

The ignitor in my used stove lasted 5 years, so that's typical, I assume. You may have a good point in that yours is staying on all the time. That could be caused by a shorted triac or stuck relay on the control board. That would certainly shorten its life, although causing a fuse to blow, I don't know.

I'd also go over every inch of the wires that feed the ignitor. One could be pinched, causing enough of a short to take out the fuse, but not right away.

The last one that quit was reading 233k ohms! I inspected all wires and didnt see anything. The St. Croix tech guy said if it were staying on, that shouldnt burn it out. He said it would shorten the lifespan of it but not burn out in 10 min. He said it could stay hot for an hour without damage.

 

[Clay H]

Update: I hand lit the stove the other night and when I turning the power on, I had my VOM hooked to the 2 leads that power the igniter. It should have power for a few minutes and then go off right? Well an hour and a half later the power to those 2 leads was still 120v. Is it the "proof of fire" switch that turns off the power to the igniter? I know whats happening here just dont know why.

 

[jzm2cc]

The POF snap disk tells controller that fire is established, proceed with feeding pellets. If this snap disk doesn't work stove will shut down after fire has been burning for 10 minutes or so.

I've seen igniters stay in indefinitely before (until they burn open circuit ). With Quadrafires its controlled by a relay, on your stove I believe its a Triac. I can double check my Prescott later in the week, but guessing its shorted internally verses software telling it to stay on. If you're skilled with a multimeter it shouldn't be to hard to isolate triac, confirm a short or not, and replace if necessary.

 

[heat seeker]

It's true that the POF snap disc tells the ignitor when to shut off, but as jzm2cc says, if the disc were bad, after a while the stove would shut down because of "lack of fire". I agree it's probably a bad triac; inexpensive generic part, but requires soldering on the control board.

 

[Clay H]

The POF snap disk tells controller that fire is established, proceed with feeding pellets. If this snap disk doesn't work stove will shut down after fire has been burning for 10 minutes or so.

I've seen igniters stay in indefinitely before (until they burn open circuit ). With Quadrafires its controlled by a relay, on your stove I believe its a Triac. I can double check my Prescott later in the week, but guessing its shorted internally verses software telling it to stay on. If you're skilled with a multimeter it shouldn't be to hard to isolate triac, confirm a short or not, and replace if necessary.

Now we are getting somewhere! This relay is on the control board? A picture would be worth a 1000 words right now. THANKS!
And please tell me how to trouble shoot this with my VOM.

 

[Clay H]

It's true that the POF snap disc tells the ignitor when to shut off, but as jzm2cc says, if the disc were bad, after a while the stove would shut down because of "lack of fire". I agree it's probably a bad triac; inexpensive generic part, but requires soldering on the control board.

There was no lack of fire on last test, I hand lit the fire. But I get what your saying about the POF.

 

[jzm2cc]

I'm 90% certain it's a 3 legged triac not a relay, but i won't be near my Prescott EXP until Thanksgiving. I have a Lancaster near by, but it doesn't have an igniter, so i assume board is different. There are different iterations of St Croix boards out there too within a given model However, the wiring should be the same at the circuit board connector and I'm willing to locate the triac on my board, take a pic, along with showing how to check pins for shorts. Obviously you know how to start stove manually so its still usable.

 

[heat seeker]

My stove, for what it's worth, has triacs. You can use the wiring diagram to locate where the ignitor connects to the board, and follow the traces to the triac. Or, and it's easy enough, test all the triacs with your meter. The shorted one is the culprit...
You can find the pinout for your triacs online somewhere, no doubt.

 

[Clay H]

Would these white gizmos be triacs? Towards to lower part of the board as it sets. (better desribed as the left side maybe)

 

[Clay H]

Scratch that, this pic showes those white gismos have 6 legs...

 

[jzm2cc]

No they are the black ones with 3 legs. Some are laying horizontal, others are vertical. Read the numbers on the part and post it on here.

I'll look at schematic and finder igniter pin on connector. From there you can isolate which triac powers igniter, or look for resistance contrast between triacs to reveal bad one as suggestes earlier by Heat Seeker.

I also see a relay on that board, it's black rectangle device between transformer and large blue and white capacitor. That could also power igniter.

 

[Clay H]

I can't do these kinda repairs. If I can isolate the bad part, where would one take it to be repaired?

 

[jzm2cc]

Assuming I'm looking at the correct schematic for your stove, the red wire goes to the igniter and its pin 6 on your circuit board. Ohm out between this pin and the triacs and relay to isolate the correct igniter driver. Once you find it, ohm triac pins to see if shorted. Can compare to other like triacs they should not have low resistance

If its the relay, then contacts could be welded together, keeping igniter on.

 

[jzm2cc]

Any electrical repair shop could un solder and resolder part. You can order parts online. Also check for damaged parts near by like resistors and burned circuit board traces.

 

[Clay H]

Assuming I'm looking at the correct schematic for your stove, the red wire goes to the igniter and its pin 6 on your circuit board. Ohm out between this pin and the triacs and relay to isolate the correct igniter driver. Once you find it, ohm triac pins to see if shorted. Can compare to other like triacs they should not have low resistance

If its the relay, then contacts could be welded together, keeping igniter on.

Kool, thanks

 

[Clay H]

Any electrical repair shop could un solder and resolder part. You can order parts online. Also check for damaged parts near by like resistors and burned circuit board traces.

Yeah I already inspected the board looking for burn marks, its clean as a whistle.

 

[Clay H]

Assuming I'm looking at the correct schematic for your stove, the red wire goes to the igniter and its pin 6 on your circuit board. Ohm out between this pin and the triacs and relay to isolate the correct igniter driver. Once you find it, ohm triac pins to see if shorted. Can compare to other like triacs they should not have low resistance

If its the relay, then contacts could be welded together, keeping igniter on.

I OHMed between the pin #6 and the triacs. The pic above isnt same as my board. There are 4 triacs above the relay and I located the one that goes to pin 6. Then I OHMed the 2 legs of the triacs (middle leg was not connected to board) and all 4 triacs OHMed at 75 ohms. Meaning they are good I assume. It was impossible for me to flip the board over to see where the relay connections were for sure. Any more advice? I'm still wondering about this Proof of Fire switch? Again, when I hand lite the stove, pin 6 constantly runs 120v and never shuts off. When I used the newly installed igniter, started the stove, it lit and stove ran less than 10 min. when the fuse blew and the igniter was then toast. I really just want to at least verify if its the board and if I can;t find a repair place reasonable to replace a bad component, I will buy a new board but I need proof first.

Reading this on page 2 is what has me wondering about the POF switch.
http://www.pellet-stove-parts-4less...rol board manual - st croix pellet stoves.pdf

 

[jzm2cc]

What is the part number of the triac that connects to pin #6? I'd like to look up the spec sheet.

1 pin controls the device (on/off).
The other 2 pins are for the load current.

All 3 pins need to be checked for shorts to one another 1 to 2, 1 to 3, 2 to 3, etc verses other known good triac.. Once i get the part number it will be easier to make further recommendations.

 

[Clay H]

What is the part number of the triac that connects to pin #6? I'd like to look up the spec sheet.

1 pin controls the device (on/off).
The other 2 pins are for the load current.

All 3 pins need to be checked for shorts to one another 1 to 2, 1 to 3, 2 to 3, etc verses other known good triac.. Once i get the part number it will be easier to make further recommendations.

If I can see that small writing i'll get it.
Just got back from 2 electronics shops, neither said they repair this stuff being its not a TV or computer...SMH. But both thought the components you call Triacs (they called them transistors) were good. Let me go get that part number. If I could get an emailed copy of the schematic from you, that would be great.