Interesting

I've been putting up Christmas decorations all day and the stove (Accentra II) has been on room temp (set at 65) putting along without issue. I was sitting here surfing the web and looked at the stove when I heard it kick on. I noticed it was showing the 5 blink code. As I watched, there was fire and the stove worked as it should. I know the 5 blink code is set when the ESP doesn't see a rise in temp for 35 minutes. Usually it's because it's out of pellets, is very dirty so it has restricted air flow or the ignitor is bad but I watched it call for heat and in 4 or 5 minutes I had fire. The hopper is full.

Now, the stove had been off for a half hour but that's because the room was warm. I had done a thorough cleaning last week including removing the ESP and cleaning it as well as removing the vent pipe and cleaning it with a brush. I have probably run 6 bags through it since. Just for giggles, I'll pull the stove apart tomorrow and double check everything but I don't expect to find anything. By the way, the ESP has a red wire. The room fan comes on and ramps up and down as it should.
What do you think is confusing this stove?

 

Double check everything you took apart and just make sure it’s snug back together. The piping, fines box cover, burnpot chamber is clean and cover is on tight and the ESP probe itself. Sometimes the screw that holds the ESP in place can be fickle. Get a flashlight and make sure it’s fully screwed in flush. Barring anything else, let’s hopefully chalk this up to a one off occurrence for now.

 

Maybe, just maybe it isn't cold enough in your area to possess a pellet stove, lol

 

Double checked everything. Everything is nice and tight. Surprisingly even the screw for the ESP. I want to put my Magnahelic on it to check the draft and I think I lent it to my son. I'll get it this weekend and check my draft. So far today it's been flawless.

 

It's possible!

 

Update on my 5 blink. I pulled the stove apart. Removed all baffles, combustion fan cover, ignitor cover, fines box cover, exhaust piping...basically everything that could come out, came out. I removed the ESP again and polished it. The stove was clean but that's no surprise because I had done this only three weeks ago.

I put it together and turned it on Test. I hooked my Magnehelic and got a high reading of .52. I think the specs are .50 to .60

I turned it on in Room Temp and had fire in 7 minutes. Room was cool so the stove ran for a while until the thermostat was satisfied and it shut down. a half hour later it fired up again and a half hour after that I got the 5 blink code. I left it alone and the stove ran perfectly the rest of the day...all the while with the 5 blink code.

Feed Adjustment is at 4 1/2

I am baffled

 

You sure you have a 5 blink and not a 4 blink? I know you'll get the 4 blink code if you are running off a thermostat, but it is nothing to worry about.

 

Positive. Interesting thing is I turned the feed adjustment down to 3 and since I wrote last night it's been fine. No blink. I've got to scratch my head a bit and try to figure out what's happening to make the stove thing it's not lit. Could an ESP probe be kinda bad? It's a thermocouple and in my years of working with them they are either good or bad. The wire doesn't look like it's been bent or damaged. I am going to unplug it from the board and put my Fluke on it. I have the resistance readings from Harman.

 

Sorry,you all can slam me,whatever. I have seen too many stupid dumb problems from Harmans, from the newer control boards. In my opinion, overall, the upgraded programming is very good, but seems to be many of the newer control boards create very weird problems,and intermittent problems. Even in my own stove,that I have the latest board(well last year) has done some really strange stuff!.(And,I fix stoves part time). My Accentra, with the newest board, did screwy things, over the last 1.5 years. I really am thinking that, when a Harman screws up, but can be fixed by a unplug, people think all is well. Harman still has problems with their control boards, but they will do nothing about it,because the error reporting number is low.

 

Wow, a Hormoan owner speaking the truth...You will most likely be banned, But before you go, please tell me, can the really burn rocks??

 

Bob, I can't disagree with you. I'm pretty confident that this is strictly a board issue. To that end, I removed it from the stove and checked it over carefully. The plugs are robust and nothing was loose. Ever since I did that the stove has been fine so who knows.

 

I will not go on a rant....but its like this..."The more they overthink the plumbing, the easier it is to stop up the drain"

The control logic is probably having a small glitch and this is setting the code.

The manufacturers have gone NUTZOID with the computer chips and herein lies the issue.

Likely an issue with the board.
Since you had the board out and PHYSICALLY touched it....my guess would be that there may be a hinky solder connection or a component has a crack in something.

Sadly this gremlin will probably come back to haunt.
While you can still run the stove, I would suggest getting a fresh board on the shelf and ready...

With all the tiny components on that board...all it takes is a resistor or other part to be a little hinky and things go downhill rear quick.

 

Well, the blink is back. The first thing I did was remove the ESP and measure the resistance. At 70 degrees it was 1000 ohms. Running it under hot water raised the resistance.
Next, I ran the stove on Stove Temp. In this mode the stove runs off of the ESP. I ran it from #1 to #4 and the flame rose accordingly. The room fan rose as the temp in the stove rose.
Now, switching to Room Temp. Set the dial to 75. Fire should rise but after 1/2 hour I still had a low flame and shortly after that I got the 5 blink. The stove thinks I don't have a fire.
It's gotta be the board. I am going to order one unless someone has another idea.

Snowy, I agree completely. This goes for everything these days. Cars, TV's, phones. They are great when they work. I stole this stove and so far I have $135 in it so I am not complaining. Thank goodness the boards aren't expensive.

 

IMO.... For the $15-$20 it costs for the ESP, I'd try that first. If it didn't fix it you'd at least have a spare on the shelf.

 

Cold solder connection and/or oxidized connections- neither is fun to find - In a lot of places there is not enough voltage to drive the nano amps past/ through the oxidation in connection terminals, micro switches are also not immune to this and could be the culprit as well ( think one of the safety switches). silver contacts will oxidize over time the higher the humditity the faster it happens. A standard vom will not locate this as it puts out too much voltage in the continuity mode - switch would check good out of circuit, but in circuit with super low voltage, no go or intermittent. gold plated contacts internally in switch resolve this issue. Chased these kinds of problems from 70's into the 90's. If you do not have a surge protector/ power line filter installed between the stove and outlet do so there is a lot spurious signals generated that will travel the power line causing no end of grief. MFG are notorious for not adding enough filter function in the power supplies of equipment to control this. ( doesn't even have to be something in your home)
Dell computers had a real problem with cheap capacitors in the units a bunch of years back. Fun read if you want delve into it, if still available on the web, and the list goes on.......

 

I've spent a good amount of my career working with low and high(er) voltage circuit boards so I know from whence you speak. I just pulled the board and looked at it under my lighted magnifier glass. I didn't see anything obvious but I wiped it down with alcohol and cleaned the connectors with contact cleaner. It's back in and running.
I will pick up a new ESP and install it before I replace the board. I was planning on changing them both anyways.

 

Definitely wouldn't hurt to have those replacements on the shelf...I currently have one of everything just in case...I picked up a board on ebay for $40 that had a bad convection blower triac...I replaced it ($1.16) and now that is currently running in my stove and I have the one that was in the stove as a spare.

 

Ok, board and ESP on their way. No big deal as I am running on Stove Temp. Delivery is supposed to be on Monday.

 

I agree.....try the ESP....BUT I would get a board coming.

This sort of debacle is the main reason I built my own "SUPER DUTY" controls.

All the timers/phase controls are fully encapsulated (Potted) and are all rated at a minimum of 10 amps.....a couple are 20 amp rated.

 

At least you have A FIRE...