St Croix Prescott help

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
Picked one up a few days ago with piping the last owner bought new before last season. I got everything for $200, I figure at worst i got some pellet pipe and 300 pounds of scrap metal for $200.

He said the stove worked good most of last winter, until the venting fan started acting up, often times shutting down. He replaced the vacuum switch. When I went to pick it up, he'd jumped over the switch. When I arrived, the stove was full of smoke. He couldn't fire it up, but showed a pictue he said he'd just taken of it burning well. I figured where there was smoke, there must have been fire. The one thing that did seem to fire right up was the fan he said hadn't work since last winter.

Today I got it set up in my shop. Hit the on button. Fans blew for quite a while then stopped. No spark. I came inside and read the instructions, that might help, but my first questions are about the correct wiring on the vacuum switch. I've included pictures. I see 3 electric plugs, but only 2 places to attach, what goes where? Does the tube go on the black or white port?
 

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jzm2cc

Minister of Fire
Sep 25, 2014
503
Northern Michigan
From memory and I'd have to double-check our Prescott, those exhaust motors have 3 leads, black, white, and brown, extra unhooked lead is brown.

Betting internal exhaust channels are completely plugged. Leaf blower will be your friend as well as flex cable to chase out ash behind burn pot channels.

Try jumping across vacuum switch to see if it try's to start. Is hose currently hooked up, hard to tell from pictures?

Note exhaust and convection blowers come on first about 10 seconds during initial start, then just exhaust blower runs assuming stove sees vacuum.

Any flashing lights on control panel when attempting to start( especially #2 and #3)?
 

jzm2cc

Minister of Fire
Sep 25, 2014
503
Northern Michigan
Also what mode are you trying to start? Manual, T stat, or Smart stat? If old stove you might have to use a jumper wire on thermostat black and red connections on rear of stove, otherwise it will just remain in heat setting #1.
 

Ssyko

Minister of Fire
Nov 6, 2017
2,606
Lorraine NY
The vacuum hose im thinking should be on the white nipple. The switch connection should be stamped with NO (normally open) or NC (normally closed) Im not positive on your particular stove but with only 2 connections for electrical i would assume the wiring is ok but the hose may be on the wrong side.
 

alternativeheat

Minister of Fire
Dec 19, 2013
3,797
Cape Cod, Ma.
Wiring problem aside I too am betting the internal chambers of the stove are clogged with ash. That is a common new owner problem with several model stoves including the Prescott. Simple fix, clean the stove correctly and regularly and enjoy it ( once you get the wires hooked up). I'm betting the last owner never knew this.
 

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
Here's where I'm at. I've cleaned the stove, maybe. I found the 2 panels and they were full. How high up inside does the channel go? I only had some #10 ground cable as a poker, but it pretty stiff. I only could get it to go about 6" up inside and I wasn't getting ash by the time I was done. The manual says there's a third panel, behind the ash pan. I can see one. Is it on all Prescotts or am I looking in the wrog place? Cleaned both shakers and had the whole inside of the fire box out.

Jumpers over the vacuum switch and hit the on/off. Combustion fan comes right on and something else is too, making a "rattling" noise, for lack of a better term. After 15 minutes the noisy motor stops, but the combustion fan keeps blowing. No fire, no pellets in the burn pot. At 30 minutes everything shuts down.

2nd try. I put a handful of pellets in the burn pot. His the on/off. Same motors/noisy as the first time. At 8 minutes I have flame. At 15 the "rattle" stops, same as the first time. Pellets burn out. At 30 everything shuts down as it originally did.

Both times the control was set on manual, the vacuum switch was jumped over and the on/off was flashing the whole time. The 2nd tim, at one point I pushed the auger button and nothing happened. When the 2nd attempt finished the on/off was still flashing as was the #3 light. I forgot to check the first time, but I assume it was also #3.
image.jpeg
 

Ssyko

Minister of Fire
Nov 6, 2017
2,606
Lorraine NY
Remove the panel on the back of the stove and remove the auger motor. You can make a test cord with an old lamp cord, connect the cord to the auger motor and plug into the wall outlet and verify it is turning. Also take a pair of pliers and try to hold the output shaft on the gear box while the motor is running. I am suspecting the gearbox may have lost a tooth or 2 and isn’t turning under load. Another thing to to do is see how free the auger shaft turns while the motor is out, may have to empty the hopper to accomplish this.
 

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
I hadn't figured out how to get the gearbox off when I was last out in the shop. I removed the 4- 7/16 bolts, which I assumed would let it pop off, but it didn't. Didn't want to pry until someone said it was okay. I also emptied the hopper.
 

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
The picture you posted didn't show before I made my last post. As I said, I didn't get the gear box off, so I couldn't exactly check verify the drive shaft you highlighted was turning or not, but what I remove was the motor on the topside of your picture. I assume it's the motor that turns the gearbox, which in turn turns the drive shaft. Being as the motor doesn't turn, I don't see the driveshaft turning?
 

Ssyko

Minister of Fire
Nov 6, 2017
2,606
Lorraine NY
If you removed the coil and armature from the gear box it more than likely wont be able to turn , the 2 have to be assembled for the alignment of the armature in the coil. There should be a set screw or pin on the shaft that holds the gearbox on the shaft. Try getting the gearbox off and put them back together, then plug in and test.
 

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
Finally got the gear box off, thanks to a can of "Blaster" my brother the mechanic gave me. Motor operates great. The auger is stuck like it was welded. Not a hint of movement. How do I get it out and/or unstuck?
 
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Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
Auger freed, burrs smoothed, reassembled, auger turning, throw in a few handful of pellets, auger no longer turns. Must be I didn’t hold the motor as tight enough? I can reach into the hooper and turn the auger a bit, with the pellets in, but when the motor starts, the auger freezes solid, I can’t budge the auger a bit. Bad motor/gear box?
 

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
Finally changed the auger motor and it seems to be fine. Hit start, pellets came cascading out, flame lit, burned out and in 31 minutes the stove was out with #3 lit. Hit the start button and pellets started loading again, so I’d say auger in now good.

Next issue appears to be the problem the last owner reported, the distribution fan not working. I cold only feel an ever so slight amount heat seeping from the duct, but nothing that’d heat anything. I briefly thought of jumping the fan to 110 with the previously used lamp cord, but I stopped myself, not knowing if it’s 110. So here I am again. What next?
 

Jeff2112

New Member
Aug 24, 2019
30
Newport Ctr, Vt
Powered directly it works great. When I pulled the fan out, the ground wire was hooked to nothing. I left the fan on the floor, reconnected to the stove and tried to run a cycle. It ran a cycle, but not much happened, besides the auger filling the burn pot and the combustion fan running. No ignition. Tell me there’s a switch/sensor that engages when the convection fan is put back into place.
 

jzm2cc

Minister of Fire
Sep 25, 2014
503
Northern Michigan
Is your proud of fire snap disk closing when exhaust heats up? Usually takes about 5 minutes, then room fan turns in. You can try shorting across the two wires to see what happens. Be careful though as its 110v.

Another possibility is a bad triac within control board which supplies current to fan motor. Can be fixed for like $5 if you have the skills.
 

jzm2cc

Minister of Fire
Sep 25, 2014
503
Northern Michigan
Look below vacuum switch, it's on exhaust housing. Visible in 1st and 2nd picture from your original posting.

Not sure what you meant about proud comment, free advice is always taken with a grain of salt.