Enviro M55 cast stove radomly drops to heat level 1

Hi guys and gals. I have an Enviro M55 cast pellet stove that we've have for about 5 years. About a week ago it developed a problem I've been able to figure out yet.

What happens is that while running the stove in manual, it randomly switches itself back to heating level 1. For example, I may have it set at heat level 3 and then after a day or two (or a few hours) it will switch itself back to 1.

Another interesting bit of data is that when it does switch itself back to heat level 1 it also goes through a startup sequence. If I switch it to heat level 1 myself it doesn't go through a startup sequence.

I started going through all the wiring and I did find that the cable that plugs into the "daughter board", which is the board with the control buttons on it, was loose. I re-connected that cable and I thought I fixed the problem because it ran 2 days straight without a problem. But today it switched back to heat level 1 by itself again.

I've called our local dealer who is a good guy but doesn't have a lot of experience with this particular stove. I'm trying to avoid buying a $300 mother board or a $150 daughter board.

Regards,
Marc

Thanks for the reply skinanbones. I actually did try blowing canned air over both boards. I also jumpered out the thermostat connection (which I wasn't using anyway) because I thought if the stove somehow thought it was in "auto/off" or "hi/low" setting it would keep running because the t-stat was jumpered like it was calling for heat. I always keep that slider switch in "manual".

I'm now thinking that a key clue is that when the stove drops to heat level 1 by itself it goes through a startup sequence. The agitator comes on and off every few seconds for a few minutes (just like when I initially start the stove). It normally doesn't do this when I switch heat settings. I'm running in "premium" pellet setting so after startup the agitator only comes on every 30 minutes normally.

It's as though the stove thinks that it was just turned on and set to heat level 1. Which is also odd because when I normally turn the stove off and then back on again it starts up at whatever heat level it was last set to.

Marc

skinanbones said:

Hmmm hate to say it but it sounds like the board is going bad and it's probally the master board. Sounds like it's doing a power surge restart. My stoves will do that exact thing if the power flicks off for 5 seconds. Unless your getting power drop outs or weird surges i think the boards on their way out

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Thanks again for the reply skinanbones. That makes sense. I have a decent surge protector. And I haven't noticed any power fluctuations. Guess I'll have to get a mother board on order. Like most people, I could have used that $360 on something else like pellets!

Marc

smwilliamson said:

Try in plugging the stove for 30 seconds and powering it back on and see if you can recreate the event

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Hi Scott. Are you suggesting I unplug the stove while it's running? Or shut it off first? I have unplugged it after I shut it off when I was doing some troubleshooting. But I haven't tried unplugging while it's running to see if it starts up at heat level 1 and goes through a startup sequence. That's worth a try. I guess that will tell me that for whatever reason it's responding like it has lost power. Thanks for the reply.

Marc

vinny11950 said:

Bringing this thread back to life to say a similar issue happened to my M55 FS last weekend. We were running the stove on manual mode and the heat setting would drop to level 2 on its own. ...The stove is connected to a surge protector with battery backup. I am not ruling out the battery backup either. But for now, all good.

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Hey Vinny. That's interesting. Makes me wonder if the two symptoms have something in common. Yours drops down to level 2, mine always dropped down to level 1. You have a battery backup, I don't.

I've only had the problem happen one more time after my initial post. I never did buy another mother board and I convinced myself that the problem was caused by a very short power blip. But since you have a battery backup that wouldn't be your issue.

When I was having the problem earlier we were in the middle of a big snow storm. But since then she's been chugging along pretty good.

Marc

vinny11950 said:

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It would be nice if the board had a USB plug in to connect to a laptop and give a diagnostic update over a long time cycle. Or to patch in software updates.

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Agreed. I'd like to have the source code and be able to modify it.

Marc