Question: Harman Advance Random Startup When Off

[forjack842]

Good Morning and Happy Thanksgiving to all!

This morning I awoke to the hum of the Harman fan and wondering why it was running. Stove front was very warm and opening the front door there was a pile of smoldering ash and smoke in front of the pot. I did the preseason clean in Oct and filled the hopper last week but haven't turned it to auto or manual yet. This morning the hopper is almost empty. I heard the stove start up and oscillate on/off a couple times throughout the summer. Unplugging the stove seems to clear the oscillation. Stove has a room temp probe and is functioning.
Got any ideas?

 

[alternativeheat]

Well now you know it runs, if even without input LOL ! So you're saying the stove was set to OFF, plugged in and Power Light on ? And it obviously has been running.

 

[jackman]

Mine did that in the middle of summer a few years back. That was how I knew the stove/room temp potentiometer, aka pot, on the control bad was bad. If you're handy with a soldering iron you can replace the pot for a few bucks otherwise it's a whole new board for a few hundred.

 

[forjack842]

Mine did that in the middle of summer a few years back. That was how I knew the stove/room temp potentiometer, aka pot, on the control bad was bad. If you're handy with a soldering iron you can replace the pot for a few bucks otherwise it's a whole new board for a few hundred.

Hi, to clarify, the stove was plugged in, I forgot I used it for a couple hours in mid Nov, cold rainy day. Then turned pot to off.
Woke up and fan was running. Burn pot was empty but in front of the burn pot is a tower of ash/semi-burnt pellets smoldering and smoking. I now remember the hopper was full at late summer cleaning, then I refilled before first use in Nov. So it basically dumped 2 hoppers full of pellets down forming a pyramid of sorts. I guess the stove fired up last night and dumped a few burning pellets into the top of the pyramid starting them smoldering. Its been that way all day so far. With it unplugged I'm hoping the smoke buildup will choke it out so I can clean it out and do the board R&R.

Thanks for the replies! With your experiences I know right where to fix the problems. I'm ok with replacing the pot, no prob soldering. I'll check Ebay for replacement set of pots and do them all. I was planning on pulling the board and recapping and replacing the temp pot with a 10 turn pot to better set the room temp. Thought of the external Honeywell thermostat but haven't committed yet.

 

[jackman]

I'll check Ebay for replacement set of pots and do them all.

Please report back on your ability to obtain the replacement pots. Other posters in this forum have had trouble buying the replacements so if you find a source it would be good know.

 

[forjack842]

Please report back on your ability to obtain the replacement pots. Other posters in this forum have had trouble buying the replacements so if you find a source it would be good know.

Promise. Is there a schematic and parts list around?

 

[Bioburner]

Pots are on again listed on Ebay. 3 for $20 I think
Had the same issue on a stove. New pots cured it Not the ones the plumber will be having to unplug tomorrow being the busiest day for them.

 

[jackman]

Is there a schematic and parts list around?

This is the only thing I have in my records. It was located on the inside panel of my Accentra. I've never seen a schematic for the control board.

If it's any help the eBay seller of the pots when I bought them in 2013 was "thibs23". The cost was $9 for all three.

 

[Bioburner]

Same seller, now $21. Far cheaper than $245 for a new board. If I were using the Harman more I would get another set. Only fired it 3 times so far this season as the corn eating Bixby is chewing up cheap corn and the propane stove filling the lows. Will probably get it online full time in a week

 

[forjack842]

Same seller, now $21. Far cheaper than $245 for a new board. If I were using the Harman more I would get another set. Only fired it 3 times so far this season as the corn eating Bixby is chewing up cheap corn and the propane stove filling the lows. Will probably get it online full time in a week

Thanks Guys,
Just ordered 2 sets of six 100k pots. Hopefully she'll stop her burning and cool down by Dec 4th.

I also use a propane heater most of the evening time, solar heat via windows during day. The Harmon is fired up when rainy and low sun or just damn cold.

 

[wally1234]

What are "pots" what piece is this?

 

[Bioburner]

Edited the thread title to Harman to protect the innocent

 

[Bioburner]

What are "pots" what piece is this?

Critical switch. Controls the fan and one to for the feed . Limited cycle life

 

[jackman]

What are "pots" what piece is this?

The proper name is potentiometer or pot for short. It is a variable resistor located on the control board. It consists of wire wrapped around a core that can be adjusted by moving a wiper connected to a knob. With age the wiper develops dead spots and no longer makes good contact with the wire. Replacement is the only recourse.

 

[forjack842]

Same seller, now $21. Far cheaper than $245 for a new board. If I were using the Harman more I would get another set. Only fired it 3 times so far this season as the corn eating Bixby is chewing up cheap corn and the propane stove filling the lows. Will probably get it online full time in a week

Evening all!
Just finished the three 100k pot replacement on the Advance and as typical one knob shaft finger broke off so now I'll have to order a knob/shaft. Also replaced the 1000uf/16vdc cap with a 25vdc. Its was just good practice! Its now the feed pot knob which is typically set and forget. So its not a big issue and I can adjust with screw driver.
Now I wanted to report what a fun cleaning job scraping off black goo from days of ash pot smoldering. As I initially posted, the old pots allowed the unit to autofeed unburnt pellets randomly gradually filling the ash pot 1/3 full then on one of the last erratic cycles fired off some pellets pushing them down into the unburnt pellets. Needless to say stuff burned very slowly, until it just quit. The creosote buildup was substantial throughout the lower 1/2 of the unit, getting into the exhaust fan area and blade but not into the pipe, thank God! Anyway its back up and running. Thanks Guys!

 

[alternativeheat]

Evening all!
Just finished the three 100k pot replacement on the Advance and as typical one knob shaft finger broke off so now I'll have to order a knob/shaft. Also replaced the 1000uf/16vdc cap with a 25vdc. Its was just good practice! Its now the feed pot knob which is typically set and forget. So its not a big issue and I can adjust with screw driver.
Now I wanted to report what a fun cleaning job scraping off black goo from days of ash pot smoldering. As I initially posted, the old pots allowed the unit to autofeed unburnt pellets randomly gradually filling the ash pot 1/3 full then on one of the last erratic cycles fired off some pellets pushing them down into the unburnt pellets. Needless to say stuff burned very slowly, until it just quit. The creosote buildup was substantial throughout the lower 1/2 of the unit, getting into the exhaust fan area and blade but not into the pipe, thank God! Anyway its back up and running. Thanks Guys!

Creosote sucks, the only place I get a little bit is in my clean out cap of my venting if stuck in super low burns for long times with low grade pellets. I get just enough to seal the inner cap ( actually it only happened once), I used a hair dryer to melt it so as to get the inner cap off. I had 0 on my last cleaning though. In wood burning I remember burning the stuff off with a really good hot fire for an hour or so.

 

[bogieb]

Interestingly, another person is having the same issue with a Pel Pro stove.

 

[Bioburner]

Good to hear all is well with the stove again and for a lot less than a new board

 

[forjack842]

Good to hear all is well with the stove again and for a lot less than a new board

Update: After a test burn last night I turned the blower control pot to off and went to bed. Now this has always turned off the feed and the burn pot would eventually burn out. To my surprise this morning the fire was burning away, the room was warm the blower speed was slow. Rechecked the feed pot, correctly set at 2. Moving the blower pot to off stops the blower, auto/manual switch in auto. Temp pot ~ 75 degrees. I'll try another shutdown in about an hour when I go to the garage. If this fails to shut it down I guess I put it on a power strip with a switch to kill power.

 

[Bioburner]

Try a reset by unplugging and plugging back in. Mine Harman decided to do the same thing early this season and has been fine since.
Hope you have the stove on a surge suppressor or a UPS.

 

[forjack842]

Ok I'll give the unplug/plug a try. Unit was unplugged for the board work and cleanout. Usually have it on a UPS. For this R&R work and its been just on a plug strip which is MOV surge protected.

 

[forjack842]

Ok I'll give the unplug/plug a try. Unit was unplugged for the board work and cleanout. Usually have it on a UPS. For this R&R work and its been just on a plug strip which is MOV surge protected.

Well turned out to be operator error. I turned the blower pot to the "off" position but saw the feed motor led light and go off indicating it was still feeding pellets. So I turned the blower pot past off to manual and when the feed led cam on I backed it back toward off and left it there. Stove shut off fine. So over the years with sloppy pots the operator got sloppy. With new pots exacting off position is required. I stand re-educated!

 

[Bioburner]

The fuzzy logic had a failure. Give it a good boot in the bum and pull up a chair in front of the fire and enjoy
The over $200 savings of replacing $21 of switches over a $240 board will make one warm too.

 

[forjack842]

The fuzzy logic had a failure. Give it a good boot in the bum and pull up a chair in front of the fire and enjoy
The over $200 savings of replacing $21 of switches over a $240 board will make one warm too.

That savings is really appreciated this time of year especially! Toss in another $30 for 2x set of knobs, still cheaper!
I forgot how nice a flame is and the Advance sure puts out the heat..........warms the buns very nicely! Thanks to all!
Merry Christmas & Happy New Year to all!

 

[Bioburner]

I don't care what time of year it is, $200 is a nice bounty.