Help w/ St. Croix Pepin shutting off completely....

[RWB1]

I recently purchased a used St. Croix Pepin.....test fired it at the guys house....ran great. He told me it was dealer serviced every year and recently has the combustion blower replaced. Looked the stove over with a fine tooth come....pretty clean and a really nice stove. Made a deal with him....the whole time the stove is running outside on his deck as we talked. I went out to shut it off to cool down to load it in my truck ...hit the power button and it shut off completely..??
Im certainly not an expert but I do know the combustion blower and convection blower should stay on until the temp decreases to a certain degree....Stove is 7 years old and Im thinking a control board wich is analog....that I wouldnt mine upgrading to digital but only if needed.
Another odd thing was that when he started the stove....the convection blower came on immedietely and blew cold air...?? Seemed strange to me...usually the firebox heats up and triggers the blower..He said it was like that since the day it was new.

I really like the stove....it was the right price and came with a sweet corner hearth pad, piping, copper pellet bucket and a cast iron steamer pot ......OH AND A TON OF LIGNETICS !

Any help on where to start troubleshooting would be greatly appreciated

thanks Bob

 

[SmokeyTheBear]

With the stove off and cold.

I'd start tracing all of the wiring matching it up to the wiring diagram.

Then read the manual for the stove cover to cover.

Maybe someone with an analog Pepin will chime in.

 

[RWB1]

Wiring seems fine as far as everything being connected...very well taken care of it seems. Im reading the manual now.

 

[RWB1]

After carefully reading the St. Croix service handbook I downloaded from their website (110 pages) and a black ink cartridge...lol I narrowed it down to either the "low limit" switch which tells the combustion/convection fans to stay running after the power switch is turned off until the internal temp reaches 120f.....

I also read that if the exhaust manifold temp does not rise above 120f....and the runn/ off switch is turned off the stove will shut down completely. This might be the case as the stove was fired up outside on the guys deck and thje temp was in the 30's.... Guess I will fire it back up in my heated shop and wait for it to cycle and try and shut it down.

Im still puzzled about the room air (convection) blower coming on as soon as the stove is turned on and not waiting till internal temp is warm....anyone with a Pepin please help !!

 

[heat seeker]

I don't have a Pepin, I do have an Afton Bay. The convection blower is triggered on/off by the Proof of Fire switch, which is mounted on the combustion fan housing. The fan comes on at 110º, off at 90º. Your Pepin might not work the same way. It seems to me that even though the temperature was in the 30's, the combustion blower housing should have hit at least 120º, unless it wasn't run long enough.

Yours being an analog unit, it may not behave like the digital units, due to lack of a controller/logic. I have a friend with an old analog stove (Earth brand), and he can turn the room blower on at will, at any stove temp. That just might be normal behavior for your stove.

Hope this is of some help...

 

[RWB1]

That does help thanks....the stove ran about a 1/2 hour so the temp should have been well over 120f......just got off the phone with my local dealer who called St. Croix....apparently joe blow off the street cant call tech support....anyway.. he told me that the stove would shut down if the low limit or proof of fire switch was bad so it looks like an upgrade to a digital board...still cheaper than a new stove..!!

Any other thoughts please feel free to chime in

thanks for the help

 

[heat seeker]

You can check the switch yourself - if it's defective, it's a lot cheaper than a new control board. I've gotta rush off right now, but if you want to know how to check the switch, I can post it later.

 

[RWB1]

That would be great....thanks

 

[heat seeker]

I copied this from some manual, I think it is St Croix's. It's simple enough:

Remove the P.O.F switch from the fan and heat up the contact surface of the switch with a lighter until you hear a click (approximately 5 seconds). Test the switch with an Ohm meter for continuity. The switch should be closed. If it takes significantly longer than 5 seconds, if it doesn’t click at all and never closes or if the switch is constantly closed and never opens, replace the switch.

So, all you need is a lighter and an ohmmeter. I believe the switch to be a generic one, so should be readily available.

 

[RWB1]

Low limit is ok....still wondering about the room air blower beig on from the start....? I was talking to a tech at my local stove shop and he told me St. Croix stoves go thru a test mode at start up where both fans come on together and the room air fan shuts off after 10 seconds untill the heat exchanger reaches a specefic temp....then it kicks on.

Maybe a St. Croix owner could chime in and let me know it this is correct......As I said before....the guy off the street cant call Tech support at St. Croix...you have to go through a dealer...what a pin in the asss Tech still thinks its the control board...upgraded digital board is available for $207.00

Im stumped

 

[SmokeyTheBear]

Normally the POF will start the convection blower when it makes its on temperature it does this via the controller. So if the controller THINKS the POF has made temperature on goes the blower, so a good functioning POF being off then the controller shouldn't see it as on, so the controller has to be bad at this point (or there is a bypass in place). That is why I suggested checking the wiring to the manual. If the wiring is correct then there is no bypass and it has to be the controller that is bad.

 

[heat seeker]

Low limit is ok....still wondering about the room air blower beig on from the start....? I was talking to a tech at my local stove shop and he told me St. Croix stoves go thru a test mode at start up where both fans come on together and the room air fan shuts off after 10 seconds untill the heat exchanger reaches a specefic temp....

Maybe a St. Croix owner could chime in and let me know it this is correct......As I said before....the guy off the street cant call Tech support at St. Croix...you have to go through a dealer...what a pin in the asss

I have the digital control…both blowers come on at startup for a bit, until the unit senses the vacuum switch has worked. (The heat exchanger has no temperature sensor. [see below] ) Once the reduced pressure in the burn chamber has been sensed, the room blower shuts off, and the combustion blower continues to run. The room blower won't come on until the P.O.F. sensor reaches 110º, then it runs at the speed selected by the requested heat level. The room blower won't shut off until the P.O.F sensor drops to 90º during shutdown.

Correction: the heat exchanger has only an over temp sensor, which has to be reset manually. If the plenum gets too hot, the auger is shut down, and the little red button in the middle of the sensor has to be pushed in by hand. If this happens more than once or twice, there is a problem with over firing the stove, or the room blower has quit or is clogged, etc. The problem must be corrected, as this would be a safety issue.

I have not checked the relationship between the vacuum switch and room blower for myself, but I will tomorrow. I got that information from a St Croix manual.

Hope this helps more than confuses!

 

[heat seeker]

Normally the POF will start the convection blower when it makes its on temperature it does this via the controller. So if the controller THINKS the POF has made temperature on goes the blower, so a good functioning POF being off then the controller shouldn't see it as on, so the controller has to be bad at this point (or there is a bypass in place). That is why I suggested checking the wiring to the manual. If the wiring is correct then there is no bypass and it has to be the controller that is bad.

Correct! It does appear that you have a wiring problem or a logic problem. My Afton Bay has a wiring diagram behind the left side door, complete with wire colors. I would expect that your stove has a diagram on it somewhere. They're probably both the same, and you could download it from St Croix's site.

One test you could do - cold stove, plugged in - jumper the two wires off the POF switch, and the two blowers should come on. Remove the jumper, the blowers should go off. I jump them when daily cleaning the cold stove, and it sucks the fine ash out so I don't breathe it. I'm very sensitive to the ash dust, and this enables me to clean the stove without suffering. This also helps me clean the ash traps, too. Since I have just the short horizontal exhaust, I don't worry about a bit more ash going out the tube.
But, if you don't get the same results - refer to Smokey's post.

 

[RWB1]

Thanks....I will try the jumper tommorow.....what if the blowers dont come on when I jump the POF switch...? Bad Controller..?

Im leaning toward the controller because the room air blower never shuts off when the stove is started....

thanks for the help

 

[heat seeker]

Thanks....I will try the jumper tommorow.....what if the blowers dont come on when I jump the POF switch...? Bad Controller..?

Im leaning toward the controller because the room air blower never shuts off when the stove is started....

thanks for the help

Or bad wiring. Closely examine the connections going to the circuit board before condemning it. The manual repeatedly states that while the pins may look fine, they may not be making contact properly.

Try jumping the two wires on the vacuum switch and see if anything changes (before starting the stove). You might have a bad switch, or, more likely, a plugged hose, fitting, or passage.

I would then suggest that you follow every wire and make sure it goes where it should. There aren't all that many, and they are color-coded, so it shouldn't be too long or hard a task. I like to eliminate everything possible before spending money on parts, but then I am a real Yankee C.B.

Glad to be of (hopefully) help!

 

[heat seeker]

I fired up my cold stove today, with the door open. The room blower kept on until the control faulted with #2 light blinking. I restarted the stove, closing the door after the room blower normally turns off. The blower shut off in a few seconds, and the stove completed the lighting program. So, I am convinced that the control looks for the vacuum switch, and shuts the room blower off when it sees the vacuum switch closing.
That's my story, and I'm stickin' to it!

 

[SmokeyTheBear]

I fired up my cold stove today, with the door open. The room blower kept on until the control faulted with #2 light blinking. I restarted the stove, closing the door after the room blower normally turns off. The blower shut off in a few seconds, and the stove completed the lighting program. So, I am convinced that the control looks for the vacuum switch, and shuts the room blower off when it sees the vacuum switch closing.
That's my story, and I'm stickin' to it!

In which case he needs to bypass the vacuum switch as a test only and then if the stove does as heat seeker thinks it will do you need to turn the stove off and go hunting for a plugged exhaust, plugged vacuum switch tube, a damaged or loose vacuum switch tube, or a plugged barb where the vacuum switch tube attaches to the exhaust system.

 

[RWB1]

I tried to bypass the POF swith with a cold stove.....nothing happened ....left the bypass wire attached to act like the switch was closed....started the stove...ran it for a 1/2 hr.....hit the power switch and it still shut down completely...

after this I bypassed the vacuum switch....ran the stove as normal...nothing happened....checked all the wiring...tubing...everything is as it should be.....bad board...?

anyone want to buy a Pepin...

 

[SmokeyTheBear]

Well sorta looks like bad board unless the controller barfs at a jumped POF and vacuum at start up.

Un jump the POF since you know it actually works correctly and attempt starting with just the vacuum jumped.

Where is krooser when you want him?

He has a Pepin.

 

[RWB1]

I will try that tommorow....cold stove .....pof hooked up as it should be and vacuum switch jumped. What should happen...? remember, .analog board..no diagnostics. All tubing is clear...no obstructions

 

[SmokeyTheBear]

I will try that tommorow....cold stove .....pof hooked up as it should be and vacuum switch jumped. What should happen...? remember, .analog board..no diagnostics. All tubing is clear...no obstructions

Hopefully the convection blower won't run (and the unit will fire ) until the unit gets to temp. Never run the stove except for testing if the vacuum switch is jumped.

I suspect that like the tech did that the board is likely shot. But we can rule out just about anything but the board.

 

[heat seeker]

Any updates???

 

[RWB1]

Had to put it on the back burner....flooded basement. Everythings dried out and Im gonna jump the vacuum switch tonite.....

 

[heat seeker]

Thanks!
Sorry about your basement. That bites! The water is tearing up our yard - too much of a good thing (water). But at least that's outside.

 

[SmokeyTheBear]

I hope that nothing got destroyed.

I have a passive sump and drain system. If it ever gets to the point that it needs to operate I'm going to pack it in.