Cycle ON/OFF or Slow Burn?

[bigwalleye]

I've been burning for almost two years now, and seem to remember something I read early on about stove sizing. That being: it's better to run a smaller stove flat out than it is to run a bigger stove on a low setting to keep the heat output down. Maybe I misremembered reading that, but it leads me to this question:

I've been burning consistently the last few days, and with the wife cooking/baking and holiday hosting, the house has been fairly warm, warm enough for us, around 67F. The house is fairly tight and well insulated. Normally I'd run the Harman on Room Temp around 65F, but I'm wondering if running it on a very low setting, almost the lowest, is 'worse' than letting it cycle on and off? I've been surprised that even on the lowest setting the house is maintaining 66-67F with outside temps in the high 20s / low 30s.

So, is it better to cycle on and off, running flat out to get the room warm again, or just let it lope along on a low setting maintaining an even temperature?

 

[LI-Mini-Owner]

Does your stove not have a Hi/Low option as well as On/Off? I use On/Off mode in the fall/spring (controlled by thermostat). Once it's below freezing I switch to Hi/Lo mode so that the stove does not have to go through start-up cycles. It may run for 30 minutes on the higher setting, then drop back to low until the thermostat calls for heat again. Of course of the frigid days it may stay on the higher setting most of the time.

 

[moey]

I prefer to run on low without cycling of any kind. At least in my house it seems the convection loop takes forever to get going so if you shut it down it takes a while for the rest of the house to warm back up.

 

[newf lover]

I think you'll get a lot of different conflicting opinions on this. I let mine cycle on and off, unless it gets really cold, then I put it on room temperature manual. On low, my stove seems to get dirtier quicker, and I do get some creosote forming. I don't like running it in low for extended periods of time. If I burn out an igniter quicker, I guess I'll have to live with that.

 

[bbfarm]

Last winter we ran it on smartstat - cycle on and off not knowing that our manual said we should have it on T stat - running all the time for winter.

We only use a few more pellets running it on T stat vs smartstat.

The window stays clean longer on smart stat, plus when it was shut off betweek cycles I cleaned it daily.

it was a warmer winter last year.

running it on T stat is saving our ignitor.

 

[343amc]

Mine definitely gets dirtier faster if burning on low. I'd like on/off for days when it isn't that cold out but my stove doesn't have that feature. Playing with the feed rates gets me where I need to be when it's above 35 outside.

That said, I don't know that I would want to run it full tilt all the time. I haven't ever had a need to run mine higher than 3 out of 5, but we haven't had a "real" winter since I got this stove.

 

[bigwalleye]

Thanks for all the replies. My Harman does have a Room Temp (thermostat mode - auto) and Stove Temp (maual mode). I have been waffling between running it on the Room Temp mode (where I get 7-9F degree temp swings) or just running on Stove Temp mode on Low to maintain it at a steady temp without the room getting up to 75F (neither my in-laws that are visiting nor I like it real warm). By the way, I'm heating about 1300 square feet of open living space with it with one ceiling fan in an opposite room for circulation.

Anyways I ran it on manual mode overnight, on a low setting, then turned it up for about 4 hours to run it on a higher setting this morning just as a change of pace, and now back to low. When I think about it, this is pretty much what it does by itself on thermostat mode when its colder outside. It will maintain on a low temp/relatively similar to my manual low temp. I guess I'm just deciding when the highs and lows will occur. I'll probably get back to running it on Auto mode once we return to our normal work schedule after the holidays are over.

 

[tsmith]

I run my Accentra on Room temp manual. I just let it do it's thing. When it needs to ramp up it does and then goes to maint. burn. They were built to do this, so let it do it's job.If you clean it regularly including the vent system, you should not have anything to worry about.

 

[DOLLARBILL]

I run my XXV on RT Manuel I like that it keeps the House warm not matter what when we grt home and it isnt as warm as we like well you know the drill we turn it up a little ! I think you have to play around and see what works best for you Good Luck !

 

[jtakeman]

I have tried both in the last couple a weeks. The weeks I was using hi/lo in the evenings I was averaging 1 1/2 bags a day. The weeks I was just letting the stove cycle with the stat it was averaging 1 bag a day. Same pellets and roughly the same outside temps. It is a bit easier on my igniter is about the only gain I see with hi/lo.

With all the variable involved, You might want to do your own test to see what works best for you.

 

[kcellwood]

Wow - 7-9 degree temp swing seems much. I run mine in room temp auto pretty much the whole heating season. My probe is mounted right next to my thermostat just around the wall from the stove in the hall way. The temp stays rock solid on 72 degrees. Flame goes up and down to keep it there. Occaissionly as it gets warmer outside, or lots of cooking going on the temp will hit 75 degrees max and the stove shuts down.

 

[mepellet]

Wow - 7-9 degree temp swing seems much. I run mine in room temp auto pretty much the whole heating season. My probe is mounted right next to my thermostat just around the wall from the stove in the hall way. The temp stays rock solid on 72 degrees. Flame goes up and down to keep it there. Occaissionly as it gets warmer outside, or lots of cooking going on the temp will hit 75 degrees max and the stove shuts down.

so even in room temp auto the stove never shuts down?

 

[jdempsey]

I prefer to run on low without cycling of any kind. At least in my house it seems the convection loop takes forever to get going so if you shut it down it takes a while for the rest of the house to warm back up.

+1 on that. A constant steady flow of heat works best in my situation also.

 

[Northwoodneil]

I've been running mine on room temp all year so far and it does an amazing job of keeping the heat even. I must have enough heat loss because even when the sun shines in it doesn't overheat. If I have one complaint it would be that if the stove shuts down it doesn't relight quite soon enough(for my liking), maybe 4 degrees below where it's set at. I have a tattle tale thermometer and and sometimes the temp never varies even 1 degree for several days.

 

[subsailor]

Thanks for all the replies. My Harman does have a Room Temp (thermostat mode - auto) and Stove Temp (maual mode). I have been waffling between running it on the Room Temp mode (where I get 7-9F degree temp swings) or just running on Stove Temp mode on Low to maintain it at a steady temp without the room getting up to 75F (neither my in-laws that are visiting nor I like it real warm). By the way, I'm heating about 1300 square feet of open living space with it with one ceiling fan in an opposite room for circulation.

Anyways I ran it on manual mode overnight, on a low setting, then turned it up for about 4 hours to run it on a higher setting this morning just as a change of pace, and now back to low. When I think about it, this is pretty much what it does by itself on thermostat mode when its colder outside. It will maintain on a low temp/relatively similar to my manual low temp. I guess I'm just deciding when the highs and lows will occur. I'll probably get back to running it on Auto mode once we return to our normal work schedule after the holidays are over.

I'm not quite sure you understand how the stove works. You have room temp auto and manual and stove temp auto and manual. Unless I'm misunderstanding your post, it sounds like you think room is auto and stove is manual.

 

[kcellwood]

Yes the stove will shut down in room temp auto if the temp gets high enough. But, during this time of year when temps are in the 20's or below it almost never shuts down. stays on low burn if need be and keeps the temp right on target. I have a nice airy log home. R value I don't want to know......

 

[bigwalleye]

re Subsailor

per page 25 of my P35i instruction manual, under section e. Igniter Mode Switch, in AUTOMATIC, igniter will automatically start the fire in either Stove Temp or Room Temp mode:

Stove Temp - ignition mode will start the fire only. Since Stove Temp maintains a constant output, the fire will never go out to need to be re-ignited. (this sounds like a manual mode to me).

Room Temp - ignition will start the first fire. Then, if room temp is satisfied, the fire will go out. Once room cools, the ignition mode will start another fire, and so on. This mode provides fully automatic temperature control. (this sounds like an automatic mode to me)

so, with the igniter in Auto mode, my sense is: Room Temp is running it in Auto mode, where the stove will maintain a temp, shut down and re-light itself, while Stove Temp is running it in Manual mode where I set the temp and where it will run until it runs out of pellets or I re-fill it. Am I wrong?


re kcellwood

I've got my external temp sensor thingy running around the corner of my fireplace and not in the direct output of the heat. When I set the Room Temp control on 65, I will see the temp of the room drop to app 57-58F before the stove re-lights itself (automatically). My temp sensor is probably 15 feet from the thermometer, in an open room, so the temp at the sensor could be a degree or three different at the sensor. I'll need to re-check that one to see what the real diff is.

 

[THE ROOSTER]

What is room temp manual vs. room temp auto? Just not letting the stove relight if it shuts off?

 

[mepellet]

What is room temp manual vs. room temp auto? Just not letting the stove relight if it shuts off?

Room temp manual - stove will never completely go out. When there is a call for heat, the distribution/convection blower turns on and stove heats until Tstat is satisfied. When there is no call for heat it goes into what is called a maint. burn. Just a small fire in the burnpot and the distribution/convection blower turns off. Similar to what other stoves call hi/lo except the distribution/convection blower turns off in "low."

Room temp auto - Stove will go out when there is no call for heat and will automatically turn on when there is a call for heat. Similar to what other stoves call on/off.

Not sure if you own a Harman but if you do, read this:
https://www.hearth.com/talk/threads/how-your-harman-works-what-your-manual-doesnt-tell-you.91030/

 

[kcellwood]

bigwalleye - I do not see that at all. I have not checked to see what the temp goes to in the room where the stove is but the probe sits right under my thermostat and stays within one degree. No large swings like you see.

 

[THE ROOSTER]

Thanks mepellet. Yes I own a Harmon, mainly burn in stove temp. never have liked the idea of the fan kicking on and off & here in Ky. The temps very rarely get very cold for very long. This stove temp manual would be great for someone that the igniter is out on their stove.