Intermittent issue...What can the problem be?

[LunaRaevn]

Second Lennox Bella having same problems as first Bella. Am considering any possible problems at this point. Could it be my thermostat? Should I have them take it off the thermostat and just operate it manually or is it still going to do the same thing?

Problem behavior: Fan that keeps flame alive is shutting off intermittently. Usually, but not always, it does this during the shutting down mode. (Sometimes during Heating mode.) Shutting Down mode is 60 min. For some reason one of the fans shuts off, fire begins to die down, while auger still feeds at low rate (as the auger should during shutdown mode). Sometimes fan comes back on, fire revives. Sometimes fan does not come back on, fire dies and is smothered by auger feed. So, stove shuts off with 'no fire' error message. This happens intermittently. No fun when it happens during night, or I am away, and I either wake up to or come home to a cold house.

Proof of fire switch replaced. Snap switch replaced all during first fire season with first Bella stove. Same problems present at beginning of second fire season. More parts replaced, lots of head scratching, hair pulling and tech calls. Dealer decides at end of second fire season to replace that Bella with a new Bella. That season ended without further issues. But I did not have to use the new stove much after it was installed in May of that year. However, barely getting into my 3rd burn season same behavior presents in addition to an issue with the igniter. The igniter would not shut off. It was staying hot constantly. So, then I had an intermittent fire problem with an igniter burning itself up. They rigged the stove up so that I would just have to insert a fuse when I needed to light fire, then take fuse out to preserve igniter until they could also resolve the fan/fire issue. By the end of the fire season (2014-15) all switches, igniter, and motherboard were replaced on the new Bella. So, that means I'm beginning this fire season (2015-16) with my Bella having new switches, new igniter, and new motherboard. Things should be running smooth this season right??

Well, I have been running stove for two weeks and this intermittent behavior has caused the stove to shut off 3 times already. Dear Powers That Be, we are only 2 weeks into the season.....

What can the problem be? I'm ready to consider anything, no matter how silly it might seem.

 

[jzm2cc]

Second Lennox Bella having same problems as first Bella. Am considering any possible problems at this point. Could it be my thermostat? Should I have them take it off the thermostat and just operate it manually or is it still going to do the same thing?

Problem behavior: Fan that keeps flame alive is shutting off intermittently. Usually, but not always, it does this during the shutting down mode. (Sometimes during Heating mode.) Shutting Down mode is 60 min. For some reason one of the fans shuts off, fire begins to die down, while auger still feeds at low rate (as the auger should during shutdown mode). Sometimes fan comes back on, fire revives. Sometimes fan does not come back on, fire dies and is smothered by auger feed. So, stove shuts off with 'no fire' error message. This happens intermittently. No fun when it happens during night, or I am away, and I either wake up to or come home to a cold house.

Proof of fire switch replaced. Snap switch replaced all during first fire season with first Bella stove. Same problems present at beginning of second fire season. More parts replaced, lots of head scratching, hair pulling and tech calls. Dealer decides at end of second fire season to replace that Bella with a new Bella. That season ended without further issues. But I did not have to use the new stove much after it was installed in May of that year. However, barely getting into my 3rd burn season same behavior presents in addition to an issue with the igniter. The igniter would not shut off. It was staying hot constantly. So, then I had an intermittent fire problem with an igniter burning itself up. They rigged the stove up so that I would just have to insert a fuse when I needed to light fire, then take fuse out to preserve igniter until they could also resolve the fan/fire issue. By the end of the fire season (2014-15) all switches, igniter, and motherboard were replaced on the new Bella. So, that means I'm beginning this fire season (2015-16) with my Bella having new switches, new igniter, and new motherboard. Things should be running smooth this season right??

Well, I have been running stove for two weeks and this intermittent behavior has caused the stove to shut off 3 times already. Dear Powers That Be, we are only 2 weeks into the season.....

What can the problem be? I'm ready to consider anything, no matter how silly it might seem.

Your idea of trying stove in manual mode is a good idea. Also check polarity of wall outlet. Harman stoves are sensitive to polarity, maybe the Bella is also. Good luck.

 

[LunaRaevn]

Your idea of trying stove in manual mode is a good idea. Also check polarity of wall outlet. Harman stoves are sensitive to polarity, maybe the Bella is also. Good luck.

Thank you jzm. I will get that checked out then.

 

[bogieb]

Do you have it set up with either UPS or surge protector? Not sure not having one would affect anything on that stove, but certainly can't hurt.

 

[Bioburner]

As bogieb suggests, a UPS may help if there is a power issue throwing the stove into having fits. Would not be the first stove having problems only to find a poor power issue. A better UPS will have indicators for polarity, voltages, and interruptions. My home was plagued by poor power and invested in several UPS systems to save stoves, TVS etc . Finally found trees touching lines and have only had one issue since when there was a issue with the meter box being infested with wasps.

 

[LunaRaevn]

The latest...any ideas?

So, I made notes on stove behavior for several days. Found that it is just the convection fan turning off and coming back on intermittently. It seems to do it only during shutdown mode. The timing varies. Sometimes it shuts down only few min. into shutdown, sometimes half-way through it, sometimes just a few min before it switches into cool down mode. The duration of the intermittent shutdown varies too, somewhere between 2 to 4 min in length.

I thought maybe convection fan is overheating. I opened that area up and cleaned it up best I could. Problem persisted.

I removed the automatic thermostat wire and started operating stove manually. The problem has not demonstrated itself since. But, in manual operation there is no shutdown mode. When I turn the stove off, it goes straight to cool down mode. Is that why problem has not demonstrated itself- because there is no shutdown mode when operating manually?

What does this indicate? Is there something glitchy about shutdown mode? Is the fan overheating? Why does it not overheat in manual operation? Is the thermostat at fault? If yes, how so? Wish I could figure this issue out.

 

[CleanFire]

You should get the electrical circuit the stove is currently hooked up to checked / tested by an electrician - see bogeib's and bioburner's recommendations above, re: UPS to help in the interim.
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My guess: (2) different stoves, same issues / parts replaced over a 3 year period, electrical (or venting) would be the constants in your home vs. the 2 stoves..

Edit: what type of thermostat? Wired, wireless? Does the thermostat use a battery? When was the battery last changed? That may be another area to check.

 

[LordmetalZ28]

That convection fan is controlled usually by your low heat snap disk. You need to stick a meter on that motor and all components back. Could be a loose wire. Or a faulty board you have to figure out at what componet is dropping the power to the motor.

 

[LunaRaevn]

You should get the electrical circuit the stove is currently hooked up to checked / tested by an electrician - see bogeib's and bioburner's recommendations above, re: UPS to help in the interim.
--
My guess: (2) different stoves, same issues / parts replaced over a 3 year period, electrical (or venting) would be the constants in your home vs. the 2 stoves..

Edit: what type of thermostat? Wired, wireless? Does the thermostat use a battery? When was the battery last changed? That may be another area to check.

Makes sense to consider what the constants have been, the electrical and venting.
As for thermostat questions: It was wired to the stove, but it also has a battery in it- two AA's. It is no longer wired to stove. Since removing it from the stove, I've not had any issue with the stove.

I feel like I need a primer on thermostats. Don't know enough about them to ask questions. Is there such a thing as being able to hook a stove up so that you have the option of running from thermostat or manually in the programming? With this Bella I have to remove the jump wire and connect the thermostat wires; reverse that to run it manually. Right now I'm running it manually. I just run it at a lower setting too, since it isn't kicking on and off all the time like it does on thermostat.

Is the problem that the thermostat is running on battery? Should I get one that is wired into the house's electrical system?

 

[bogieb]

Is the thermostat millivolt compatible? I'm unsure about your stove, but I know my St. Croix needed such a stat.

 

[CleanFire]

I don't want to give you bad info. - it sounds like you are familiar with how to connect / disconnect the thermostat, so that's cool.
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Our Honeywell 'smart' wired thermostat, on the FHA oil furnace here, which also takes batteries, it mis-behaves when the batteries are low, so we change them every the first day every fall, and spring. I'd try changing the batteries, and possibly the wired cable, if at all suspect, first. (Note to self, buy more batteries.)
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I don't own the Lennox Bella stove (nice stove, BTW), and can only go by what I read in the manual, link:

(broken link removed to http://matchless.info/wp-content/uploads/2013/09/Lennox_Hearth_Bella_Installation_Operation_775226M.pdf)


It doesn't appear you can select between 'auto' and 'manual' modes when a thermostat is hooked up. That would be a dealer question.

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I do think there is another issue, besides any potential power issue, I just don't know what it is.

It appears your stove has a manual draft adjustment (page 10), but without knowing the burn characteristics when running in low (maintenance) mode for that 60 minute period, I cannot say if adjusting the draft damper would afford any burn improvement / or is needed.

re: venting, stove, this link on deep-cleaning the stove may be helpful, link:

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Hope this info helps.

 

[LunaRaevn]

I don't want to give you bad info. - it sounds like you are familiar with how to connect / disconnect the thermostat, so that's cool.
--
Our Honeywell 'smart' wired thermostat, on the FHA oil furnace here, which also takes batteries, it mis-behaves when the batteries are low, so we change them every the first day every fall, and spring. I'd try changing the batteries, and possibly the wired cable, if at all suspect, first. (Note to self, buy more batteries.)
--

It doesn't appear you can select between 'auto' and 'manual' modes when a thermostat is hooked up. That would be a dealer question.

--
I do think there is another issue, besides any potential power issue, I just don't know what it is.

It appears your stove has a manual draft adjustment (page 10), but without knowing the burn characteristics when running in low (maintenance) mode for that 60 minute period, I cannot say if adjusting the draft damper would afford any burn improvement / or is needed.



Hope this info helps.

Thank you CleanFire,
I'll change batteries now. Have just been spending some time trying to educate myself on the thermostat. Am curious what the "cycles per hour" on the stat should be set at....if anyone knows what is best?

I still have my Bella manual and referred to it on how to clean fans and motor area. Also on how to change it from stat hookup to manual operation.

I've gone two days on manual operation without any issues. Am tempted now to switch back to stat with new batteries and see what happens. But, I have liked that on manual I have only had to turn the stove off twice in 24 hours. Just running it on lowest settings is keeping things comfortable for now. On stat it is off and on constantly! That is why I ask about "cycles per hour". Wondering if a setting in that feature would lesson how often Bella is shutting down and turning back on. But that is a minor issue I guess compared to figuring out this other glitch with the fan.

Thanks everyone really for all the responses. Might get the right answer eventually with all these heads coming together.

 

[CleanFire]

I'll change batteries now. Have just been spending some time trying to educate myself on the thermostat. Am curious what the "cycles per hour" on the stat should be set at....if anyone knows what is best?

If you could post the brand name, and model number of the thermostat (should be a really tiny sticker that will probably require a high power magnifying glass to read it..), we all could take a look and try to help out with that.

 

[SmokeyTheBear]

Locate both the low limit and convection blower snap switches, the low limit switch is located at the combustion blower, it must be tight against the blower mounting and clean (free of ash) otherwise the stove will enter shut-down due to what it thinks is loss of fire. Remember the stove should be off, cold, and unplugged before playing around. There is also a convection fan control snap switch mounted on a bracket with several other snap discs, once again it must be tight against the bracket and free of dust. Loose wiring connections to and from these switches can cause intermittent operation. Operating any stove can lead to loosening of connections due to repeated heating and cooling cycles.

 

[LunaRaevn]

So, since putting new batteries in stat and running it on stat again, this is what is happening:

• CV fan shut off during heat mode (used to glitch during low-heat mode before going into shutdown; in proper run cycle, I believe it goes off during the Cool down mode)
• Stat is "clicking" more frequently.
• Stat is registering that room is to temp but stove did not go into low-heat mode for almost 10 min afterward.
• Stat "clicked" again like it was registering a new temp. But temp was still same 70/70 but stove went back into heating mode from low-heat mode. Why??

Stat is a 5000 series Honeywell. Did I mess up a setting on it when changing batteries?

Smokey, I will open sides again and check connections. I've cleaned in there twice this week now while looking for what is causing the glitch. Will check again that I've not knocked anything kelter.

 

[SmokeyTheBear]

Define exactly what you mean by clean in there, the switch on the combustion fan would in all likelihood need to be removed to get to the temperature detection button which is frequently in the exhaust stream where it will get covered and insulated by ash. You have to make certain that the button is clean in both cases. That Bella has a fairly complete diagnostic display please provide what the stove is displaying, when a stove changes firing state it does so in a programmed manner and in the case where it goes from a high firing rate to a lower one it takes a while before the fuel in the burn pot reflects the new lower rate. In other words the change is not instantaneous. Hopefully the low limit switch is a ceramic one but that is another story in and of itself.

 

[CleanFire]

Stat is a 5000 series Honeywell. Did I mess up a setting on it when changing batteries?

I wish I could help, but have no idea - looking at the setup sheet, that is one complicated thermostat.

I did find other posts on the 'net about the 3000 series, from owners that echoed setup & operating difficulty, including on the Lennox website, FYI.

--

* Hopefully other members here reading can give you some suggestions, recommendations, or pointers to existing posts here, on an simple thermostat that is compatible with your stove.. (Our stove here is different than yours & has an integrated room temp. probe, so no external thermostat was needed.)

 

[SmokeyTheBear]

Any tstat used on a pellet stove needs a dead zone (normally set using a swing setting), that prevents the stove from attempting to change from high to low (or vice versa) or from starting prior to actually getting shut down which for some stoves causes a lot of issues.

Your stove has multiple switches that do the honours of deciding what is up, the convection temperature snap disc on the bracket lets the convection blower run when the stove is hot enough to need it running in order to keep it under high limit shut down conditions, how it functions has nothing to do with what state the stove is in.

In fact it is even possible that if you have the heat setting down low and the convection fan control on high that the convection fan is removing enough heat to lower the temperature where the thermo disc is to below its turn off setting thus causing the convection system to turn off. It is also possible that under the same run conditions that ash build up on the heat exchanger is getting in the way of the temperature at the thermo disc from being high enough to keep the fan running.

If you left your stove plugged in over the summer without it being on a decent surge protector and there were storm induced power surges there is a possibility that the control board has been zapped.

 

[LunaRaevn]

Well, I took it back off stat. Stove runs perfectly when not hooked up to it. But, it also doesn't have to go through the "low heat, shutting down in ## min" either, which is when it has problems when hooked up to the stat.

I keep stove unplugged during summers.

So, for now all I know is that it runs good on manual operation. I just have to be there to turn it off/on or up/down now. Would like it to operate on stat but....

 

[SmokeyTheBear]

Exactly what model of the 5000 series do you have? The one who's manual I read doesn't have a swing or anticipater setting. It would not work well at all with a solid fuel heating device.

 

[LunaRaevn]

It says TH5110D1022 on it.
The dealer installed it the same day they put in the stove. How do I know if it is compatible with my stove or not? Why did they put in this thermostat if it can't be used with the pellet stove? Interesting, since it is the one constant that has been with both stoves....

SO, if I'm going to replace thermostat, what kind do I need with a pellet stove? I have no other heat source to hook up to it. It would just be the pellet stove.

 

[LunaRaevn]

So, replaced the stat. Same issues presenting during heating and low-heat modes. Still never happens when operating manually.

Also picked up a surge protector with stabilizer. Not hopeful anymore that that will resolve anything. But, it will hopefully protect the new motherboard if that is what we end up having to replace...again....in less than 6 months since last one was replaced.

 

[smwilliamson]

Here's what I know about Bella's and Tstats. When the stove is hot and there is a call for heat the stove works to meet demand. When demand is met the stove rolls into a maintenance/shutdown mode which I think lasts for about 50 minutes. during this time the room blower will run for a short time then shut off as it should, since demand has been met. for the next 30 minutes, if demand is called again, the stove will return to run mode from maintenance mode. If there is no call after 30 minutes, the fan comes back on to hurry and cool the low limit and restore room heat so the unit can shut off. BUT if it calls for heat during that last leg, the stove returns to start up mode but the low limit is still open and the software just lets out a fart and dies. It's called short cycling. many Tstats have CPH's built into them that will only allow the tstat to call for heat once an hour. Perhaps try and get a switch like that?

 

[LunaRaevn]

When the stove was running properly, cv fan came on a little while after ignition mode started. CV fan then ran all through heating cycle and low-heat mode (60 min.maintenance). If heat was not called for by end of low-heat mode, stove would go into shutdown mode and cv fan would turn off.

It is glitching now, where the cv fan is shutting off during heating and maintenance modes. It quits running intermittently- sometimes for 2 min, sometimes up to 4 min. Pellets will pile into burn pot, acting like it has gone back into ignition phase but the display board says it is in heating or low-heat modes. It totally is not doing that when operating manually.

 

[smwilliamson]

The stove is restarting. During start up the fan is off. That's the shut off. The pellets piling is the programmed feed rate during start up which is two minutes of feed constant to fill the pot. That's why it's ok during manual mode. I think you have a short in your tstat wires if not, then tstat short, if not then control board issue but you replaced the board and the problem is still around. Traces the tstat wires from the board to the tstat wire connections. I think you find the problem there.