Stove Temp vs Room Temp

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I will for sure try out stove temp manual in the dead of winter, as I'm always wanting to save pellets, but I don't understand one thing, how low will the stove go down to when on manual and the stove is at it's set temp? It seems to me that it will only go down as low as low fan on #1 so I don't see how that can save on pellets.
 
I have tried running the stove on Room Temp Manual and the outside and top are getting warm/hot to the touch which was not the case in Room Temp Auto. Is this just a function of the stove running non stop but nit need ing non stop heat or do the stoves just run hot to the touch when on continuous run?
 
Room Temp for me. I extended the probe wires to a good spot and run it at 72. I am on my 3rd year burning and have not replaced my igniter yet. I do have a MAP torch just in case It does go, and my Heat pump/Electric heat is set at 64 in case it doesn't light at night. When it gets real cold it really doesn't cycle on and off though.
 
jdege said:
I have tried running the stove on Room Temp Manual and the outside and top are getting warm/hot to the touch which was not the case in Room Temp Auto. Is this just a function of the stove running non stop but nit need ing non stop heat or do the stoves just run hot to the touch when on continuous run?

What happens is the distribution fan turns off and the stove is still running so it "heats up". It is fine but it is a waste of heat.
 
Trickyrick said:
jdege said:
I have tried running the stove on Room Temp Manual and the outside and top are getting warm/hot to the touch which was not the case in Room Temp Auto. Is this just a function of the stove running non stop but nit need ing non stop heat or do the stoves just run hot to the touch when on continuous run?

What happens is the distribution fan turns off and the stove is still running so it "heats up". It is fine but it is a waste of heat.

Stove distribution fan doesn't turn off on room temp, switch set to manual (unless it's on mantenance burn in which the distribution fan will over cool the stove and reduce efficiency). How is a hot stove a waste of heat? That's not wasted energy, just stored energy which will dissipate into the room at some point.

My XXV get's nice and hot to the touch, love it.
 
I only run the stove in room temp during the shoulder seasons and switch it over to
stove temp mid season.

Seems to keep the house a more comfortable temp and less wear and tear on the ignitor.
 
lbcynya said:
Trickyrick said:
jdege said:
I have tried running the stove on Room Temp Manual and the outside and top are getting warm/hot to the touch which was not the case in Room Temp Auto. Is this just a function of the stove running non stop but nit need ing non stop heat or do the stoves just run hot to the touch when on continuous run?

What happens is the distribution fan turns off and the stove is still running so it "heats up". It is fine but it is a waste of heat.

Stove distribution fan doesn't turn off on room temp, switch set to manual (unless it's on mantenance burn in which the distribution fan will over cool the stove and reduce efficiency). How is a hot stove a waste of heat? That's not wasted energy, just stored energy which will dissipate into the room at some point.

My XXV get's nice and hot to the touch, love it.

If the distribution fan isnt running then more BTUs are going out the exhaust. That is wasted heat.

I agree the distribution fan doesnt turn off in manual but in room temp it does. that will allow the top and front to heat up and because you do not have turbulent flow through the exchanger you are wasting heat.
 
Trickyrick said:
lbcynya said:
Trickyrick said:
jdege said:
I have tried running the stove on Room Temp Manual and the outside and top are getting warm/hot to the touch which was not the case in Room Temp Auto. Is this just a function of the stove running non stop but nit need ing non stop heat or do the stoves just run hot to the touch when on continuous run?

What happens is the distribution fan turns off and the stove is still running so it "heats up". It is fine but it is a waste of heat.

Stove distribution fan doesn't turn off on room temp, switch set to manual (unless it's on mantenance burn in which the distribution fan will over cool the stove and reduce efficiency). How is a hot stove a waste of heat? That's not wasted energy, just stored energy which will dissipate into the room at some point.

My XXV get's nice and hot to the touch, love it.

If the distribution fan isnt running then more BTUs are going out the exhaust. That is wasted heat.

I agree the distribution fan doesnt turn off in manual but in room temp it does. that will allow the top and front to heat up and because you do not have turbulent flow through the exchanger you are wasting heat.

My fan doesn't shut off on room temp, switch to manual... I would presume the fan is motor controlled by the esp temp over anything else...
 
tinkabranc said:
I only run the stove in room temp during the shoulder seasons and switch it over to
stove temp mid season.

Seems to keep the house a more comfortable temp and less wear and tear on the ignitor.

Curious about what happens to room temperatures in stove mode when outside temp swings
from lets say -10 to +20. If you are comfortable with a certain setting at -10 and do not
change it, does it get too warm at +20? Do you have to re-adjust??
 
thedude110 said:
It would be helpful if Harman would release an honest, pro-con chart of the two modes.

Yes a chart would be nice.


Here is what I have seen.
A Harman Tech at a seminar (2009) stated that Room Temp was more efficient.
We had a new control board installed this past Summer.
I have noticed the following:
1) Startup is slower ie a much more gradual fire ramp up
2)When stove shuts down the auger does not run at all. It used to feed a small
amount to help keep fire from moving toward bin.
3) Does not keep temp on setpoint like the old board. More fluctuation.

**Igniter burned out last month. Original 13 fin from 2008**

So now I am running stove in Room Temp but with the igniter in manual. (This mode is in the book)
Another forum member pointed this out to me.
This seems to keep the temp more stable and also keeps the fire going. Saves on igniter use.
 
How your stove works - The facts are pretty straightforward, but how you get people to properly interpret the facts is the hard part.

It's your toy, run it the way you want as long as you understand what's going on behind the scenes!

Everything noted below is based on me seeing what the stove is doing via the Harman diagnostic tool during the various operation methods. I get to see feed rates, max feed rates, current ESP temps, ESP set temps, room sensor temperatures, room sensor target temperatures, knob positions, switch positions, etc.


Here are the facts:

Stove temp - 100% driven the the ESP (temperature probe in stove exhaust flow). Temp dial corresponds to a fixed ESP temperature. For simplicity, let's assume a setting of 3 = 300 degrees ESP temp. The stove will ramp feed up/down to always be as close to 300 degrees as possible. In stove temp the stove doesn't care what the room temp is, only the ESP temp. The room might be 60 or 90 degrees doesn't matter, all it cares about is maintaining an ESP temp of 300.

The stove will not shut off in stove temp regardless of whether the igniter switch is set to auto or manual.

Stove temp, switch to manual - I call this fireplace mode. Distribution fan will not turn on unless the temp knob is set to 5 or higher. This is designed to give a nice fire, but not a ton of heat in the room. Most goes up the chimney.

Stove temp, switch to auto - distribution fan operates normally to push heat into the room, regardless of stove or room temperature. There is a caveat to this, if you have your room temp set to 1 (very low) then the distribution blower might shut off because the ESP temperature is below the lowest setting allowed for the distribution blower to run.

____________________________________________________________________________________________________


Room Temp - The stove is 100% driven by the room temp sensor. The stove will automatically adjust feed and ESP temp to achieve the room temp set point. Once the set point is reached, the stove will slowly throttle up/down to maintain temperature. If it's 20 degrees outside, your heat load is high and the stove will feed more pellets to get the ESP temp hot enough to maintain room temperature set point. If it's 60 degrees outside, the stove will feed as little as possible and keep as low an ESP temp as possible to maintain room temperature.

Igniter switch to manual, stove will go into maintenance burn in between calls for heat - prevents igniter cycling, might use a few more pellets in this mode...maybe...

Igniter switch to auto, stove will initiate the shut down process in between calls for heat - igniter could cycle several times per day, depends on set point and heat load. If there is a call for heat during the shutdown process, the stove will start feeding pellets provided that the ESP temperature didn't go below the low limit. So, on really cold days, the stove might not shut off, even if it's on auto.

So there's the facts, interpret away... :)

______________________________________________________________________________________________________

And more...

Feed Rates - Feed rate us controlled by the stove ESP. The stove will select a feed rate based on the actual temperature and target call for heat. The larger the temperature delta (actual room temp vs. target room temp), the greater the feed rate will be. 10 degrees would be a large delta and the stove would feed to reach max ESP temp of about 500 degrees depending on stove model. A 2 degree delta might only result in a feed rate of 20 seconds per minute even though the feed rate max dial is set to 4 (or 40 seconds per minute). The stove can vary the feed rate between 2.5 seconds per minute and the max feed rate you set. A feed rate of 6 would represent continuous feeding if the ESP wasn't seeing sufficient temperatures to satisfy the call for heat.

Feed rates can lead to incomplete combustion comes in 2 forms -
1. Pellets spilling over the edge of the burn pot before they are reduced to ash.
2. Smoke.

Relative to #1 - when you run the stove wide open, the burning pellets should come no closer than 1 inch from the edge of the burn pot. You should have burning pellets and about 1†of ash before the edge. If pellets are bulging and close to the edge, you might not turn them to ash before spilling over the edge, wasting energy. If the burn line is too close, dial the feed rate back a bit, may by 1/2 of a number (i.e. 3.5 to 3). The stove doesn't run wide open once everything is up to temp, so this is only for scenarios where, for instance, the room is 65 and you want it 75 degrees. When up to temp the stove will regulate itself form 5 seconds per minute of feed up to the limit you set.

Relative to #2 - smoke is also a sign of incomplete combustion, meaning that there is more fuel than air supplied by the combustion blower. This too should be evaluated when the stove is running WIDE OPEN. At night with a flashlight, you’ll always see smoke… During the day, smoke is rated based on opacity or how easily you can see through it. Startup might be 50% opacity or fairly heavy smoke. If you are 10% or less (barely visible), that’s reasonable and you aren't really wasting anything. If you have to struggle to see it, you’re probably good. If you can easily see smoke and your flame is HUGE, try dialing back feed rate a bit to bring the air/fuel mix back into a more efficient range. Once again, dialing it back by 1/2 of a number (ie 3.5 to 3).

In most cases, you don’t want to be below 3 or above 4. You’ll also want to recalibrate after changing brands of pellets since the blend and size of pellet will cause it to burn/feed differently.

Setting your feed rate too low doesn't save pellets and stove performance will suffer. Setting your feed rate too low is like putting a brick underneath the gas pedal of your car. Don't be tempted to set your feed rate too low.
 
lbcynya said:
The facts are pretty straightforward, but how you get people to properly interpret the facts is the hard part.

It's your toy, run it the way you want as long as you understand what's going on behind the scenes!

Everything noted below is based on me seeing what the stove is doing via the Harman diagnostic tool during the various operation methods. I get to see feed rates, max feed rates, current esp temps, esp set temps, room sensor temperatures, room sensor target temperatures, knob positions, switch positions, etc.


Here are the facts:

Stove temp - 100% driven the the esp. Temp dial corresponds to a fixed esp temperature. For simplicity, let's assume a setting of 3 = 300 degrees esp temp. The stove will ramp feed up/down to always be as close to 300 degrees as possible. In stove temp the stove doesn't care what the room temp is, only the esp temp. The room might be 60 or 90 degrees doesn't matter, all it cares about is maintaining an esp temp of 300.

The stove will not shut off in stove temp regardless of whether the igniter switch is set to auto or manual.

Stove temp, switch to manual - I call this fireplace mode. Distribution fan will not turn on unless the temp knob is set to 5 or higher. This is designed to give a nice fire, but not a ton of heat in the room. Most goes up the chimney.

Stove temp, switch to auto - distribution fan operates normally to push heat into the room, regardless of stove or room temperature. There is a caveat to this, if you have your room temp set to 1 (very low) then the distribution blower might shut off because the esp temperature is below the lowest setting allowed for the distribution blower to run.

____________________________________________________________________________________________________


Room Temp - The stove is 100% driven by the room temp sensor. The stove will automatically adjust feed and esp temp to achieve the room temp set point. Once the set point is reached, the stove will slowly throttle up/down to maintain temperature. If it's 20 degrees outside, your heat load is high and the stove will feed more pellets to get the esp temp hot enough to maintain room temperature set point. If it's 60 degrees outside, the stove will feed as little as possible and keep as low an esp temp as possible to maintain room temperature.

Igniter switch to manual, stove will go into maintenance burn in between calls for heat - prevents igniter cycling, might use a few more pellets in this mode...maybe...

Igniter switch to auto, stove will initiate the shut down process in between calls for heat - igniter could cycle several times per day, depends on set point and heat load. If there is a call for heat during the shutdown process, the stove will start feeding pellets provided that the esp temperature didn't go below the low limit. So, on really cold days, the stove might not shut off, even if it's on auto.

So there's the facts, interpret away... :)


This is a very accurate explanation.
I have been fiddling with different settings on my P43. I have found I like room temp the best. I have found that for my installation and house that leaving the stove in room temp always, then putting the stove into manual when the temp gets below 35* works great. Above 35* I flip it to automatic and it starts and stops as you would expect. I put it in manual below 35* because I noticed that the stove would go into shutdown but before the combustion blower finally stopped the stove would need to re-ignite. I love the way room temp works, and the only reason I even flip the switch to manual at that certain temp is to save on the ignitor. All of this being said I still fiddle and play. Bottom line for me is room temp in automatic works the best at my house. It burns the least pellets and keeps the house at an even temperature. Love it.
 
Thanks PJ!

(Moved content to post 36, since this is the link referenced in my signature.)
 
I have a harman P-43 and was wondering about the best place for the sensor and from what I am reading I should have it away from the stove to get the best results. This is what I wanted to do so thatnks for helping with that.
Ed
 
referee38 said:
I have a harman P-43 and was wondering about the best place for the sensor and from what I am reading I should have it away from the stove to get the best results. This is what I wanted to do so thatnks for helping with that.
Ed

Unfortunately, there's no good way other than the method I outlined above. Mine is happiest directly under the stove exhaust outlet. Corner install, basement, on tile floor over cement floor. You might need to move yours elsewhere, on a wall, etc. If it's on the floor, you shouldn't have to move it too far from the stove. You can extend the room probe up to 25 feet using thermostat wire. Just depends on your layout. Best to try and find someplace easy and close before you go extending things.

Second thought, you could use an IR temp gun to take surface temperatures around the stove area to find the temp that equals what you have set on the temp dial. Let the stove run for several hours or a day to let everything find equilibrium before trying to find the sweet spot.
 

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lbcynya said:
How your stove works - The facts are pretty straightforward, but how you get people to properly interpret the facts is the hard part.

It's your toy, run it the way you want as long as you understand what's going on behind the scenes!

Everything noted below is based on me seeing what the stove is doing via the Harman diagnostic tool during the various operation methods. I get to see feed rates, max feed rates, current esp temps, esp set temps, room sensor temperatures, room sensor target temperatures, knob positions, switch positions, etc.


Here are the facts:

Stove temp - 100% driven the the esp. Temp dial corresponds to a fixed esp temperature. For simplicity, let's assume a setting of 3 = 300 degrees esp temp. The stove will ramp feed up/down to always be as close to 300 degrees as possible. In stove temp the stove doesn't care what the room temp is, only the esp temp. The room might be 60 or 90 degrees doesn't matter, all it cares about is maintaining an esp temp of 300.

The stove will not shut off in stove temp regardless of whether the igniter switch is set to auto or manual.

Stove temp, switch to manual - I call this fireplace mode. Distribution fan will not turn on unless the temp knob is set to 5 or higher. This is designed to give a nice fire, but not a ton of heat in the room. Most goes up the chimney.

Stove temp, switch to auto - distribution fan operates normally to push heat into the room, regardless of stove or room temperature. There is a caveat to this, if you have your room temp set to 1 (very low) then the distribution blower might shut off because the esp temperature is below the lowest setting allowed for the distribution blower to run.

____________________________________________________________________________________________________


Room Temp - The stove is 100% driven by the room temp sensor. The stove will automatically adjust feed and esp temp to achieve the room temp set point. Once the set point is reached, the stove will slowly throttle up/down to maintain temperature. If it's 20 degrees outside, your heat load is high and the stove will feed more pellets to get the esp temp hot enough to maintain room temperature set point. If it's 60 degrees outside, the stove will feed as little as possible and keep as low an esp temp as possible to maintain room temperature.

Igniter switch to manual, stove will go into maintenance burn in between calls for heat - prevents igniter cycling, might use a few more pellets in this mode...maybe...

Igniter switch to auto, stove will initiate the shut down process in between calls for heat - igniter could cycle several times per day, depends on set point and heat load. If there is a call for heat during the shutdown process, the stove will start feeding pellets provided that the esp temperature didn't go below the low limit. So, on really cold days, the stove might not shut off, even if it's on auto.

So there's the facts, interpret away... :)


Dude, that is the best explanation I have ever heard for the operation of a Harman and it is exactly how I understood it to be....thanks.
 
lbcynya said:
<snip>Ideally, there would be 2 additional simple electronic displays on the control board, 1 for the room probe temp actual and 1 for the room probe set temp. This would eliminate 100% of the misinterpretations on how room temp works since you would have 2 very important pieces of information.

This is why I bought a cheap digital thermometer and placed it exactly where the room temp sensor is. Now I know precisely what the sensor is reading, and can interpret how to set the dial on the stove. I don't find the dial to be all that accurate, but it's close enough that it's easy to adjust based on what I see at the sensor.

All in all, I find "Room Temp" keeps that thermometer within a degree or two of what the stove is set to. It's not bad really... the slight difference could simply be a small variation in component values and the fact it's an analog control. Digital at the stove would be a great improvement though.

Thanks for the explanation, will clear things up for many I am sure!
 
lbcynya said:
How your stove works - The facts are pretty straightforward, but how you get people to properly interpret the facts is the hard part.

It's your toy, run it the way you want as long as you understand what's going on behind the scenes!

Everything noted below is based on me seeing what the stove is doing via the Harman diagnostic tool during the various operation methods. I get to see feed rates, max feed rates, current esp temps, esp set temps, room sensor temperatures, room sensor target temperatures, knob positions, switch positions, etc.


Here are the facts:

Stove temp - 100% driven the the esp. Temp dial corresponds to a fixed esp temperature. For simplicity, let's assume a setting of 3 = 300 degrees esp temp. The stove will ramp feed up/down to always be as close to 300 degrees as possible. In stove temp the stove doesn't care what the room temp is, only the esp temp. The room might be 60 or 90 degrees doesn't matter, all it cares about is maintaining an esp temp of 300.

The stove will not shut off in stove temp regardless of whether the igniter switch is set to auto or manual.

Stove temp, switch to manual - I call this fireplace mode. Distribution fan will not turn on unless the temp knob is set to 5 or higher. This is designed to give a nice fire, but not a ton of heat in the room. Most goes up the chimney.

Stove temp, switch to auto - distribution fan operates normally to push heat into the room, regardless of stove or room temperature. There is a caveat to this, if you have your room temp set to 1 (very low) then the distribution blower might shut off because the esp temperature is below the lowest setting allowed for the distribution blower to run.

____________________________________________________________________________________________________


Room Temp - The stove is 100% driven by the room temp sensor. The stove will automatically adjust feed and esp temp to achieve the room temp set point. Once the set point is reached, the stove will slowly throttle up/down to maintain temperature. If it's 20 degrees outside, your heat load is high and the stove will feed more pellets to get the esp temp hot enough to maintain room temperature set point. If it's 60 degrees outside, the stove will feed as little as possible and keep as low an esp temp as possible to maintain room temperature.

Igniter switch to manual, stove will go into maintenance burn in between calls for heat - prevents igniter cycling, might use a few more pellets in this mode...maybe...

Igniter switch to auto, stove will initiate the shut down process in between calls for heat - igniter could cycle several times per day, depends on set point and heat load. If there is a call for heat during the shutdown process, the stove will start feeding pellets provided that the esp temperature didn't go below the low limit. So, on really cold days, the stove might not shut off, even if it's on auto.

So there's the facts, interpret away... :)

______________________________________________________________________________________________________

And more...

Let me elaborate on why I believe room temp is an issue for some, maybe most. Where Harman FALLS SHORT is the user interface. We simply DONT have enough data.

Ideally, there would be 2 additional simple electronic displays on the control board, 1 for the room probe temp actual and 1 for the room probe set temp. This would eliminate 100% of the misinterpretations on how room temp works since you would have 2 very important pieces of information.

Here's a recant of my first experience with room temp - I hung the room temp sensor of the back of the stove (like the installer told me to) and set the temperature dial to 70 degrees, the room was COLD. I looked at the dial, I've set it to 70, but the room is cold, what gives...? Maybe I'll try stove temp, bang, lots of heat...yea. Stove temp works better. At least that was my initial impression...

>>>>>>>Information below is factual and helpful to understand how everything works, but the fact remains that you won't have access to the proper temperatures unless you pony up for a Harman diagnostic tool. You will need to use trial/error to find the balance. It's very doable, just takes a little time and effort. Sorry!<<<<<<

If I would have had a simple digital readout telling me what the room temp actual value was, I would have seen that the sensor was seeing 80 degrees while hanging on the back of the stove. If the knob is set to 70 and the sensor sees 80, the stove will go out while on auto or go down to maintenance if the igniter switch is set to manual.

Placement of the room sensor is the 100% key to success. You need to find a place that allows the room sensor to read the actual room temperature (away from drafts, stove heat, etc) in order to keep the room/area comfortable and consistent with your intended setting.

This is why I say it's also important to have a digital readout for desired temperature. "Hello Harman, A trim pot is sooooo 1970's." If you know exactly what the probe temperature is and what the set temperature is, then you can use a simple thermometer (in a comfortable location) to insure all 3 agree. If your stove is set to 70, your room temp says 70 and your thermometer says 70, your dialed in and good to go for the rest of the winter, provided you don't move the room temp sensor.

If your thermometer says the room is 67, but your stove is set and reads 70, then you know your temp sensor is too close to the stove, move it farther away to get all 3 to match.

If your thermometer says 73, but your stove is set and reads 70, then you know the temp sensor might be too close to a draft, outside, wall, cold floor, etc. and you should move the temp sensor to a different location or try to isolate it from drafts or hard surfaces. As I noted before, its very doable to get things lined up, it just takes a little time and effort with the minimal information Harman gives us on the control panel.

Rant - C'mon Harman, get with the program and leap into the 2000's and give everyone access to what's going on!!! Great stove, lots of potential if you give your customers enough data to run the stove properly!!!

Can anyone explain how the feed rate plays into all of this?
 
As I have said many times here in the past year, the feed rate on a Harman is a "set it and forget it" adjustment. My P61A is set at 3. The feed rate adjustment is a setting that controls the maximum rate that your stove will feed pellets when, and only when, the stove calls for it. Do a search on Harman feed rate.
 
So this is my strategy: Set the feed rate at 3.5 and forget it.

In the middle of the winter room temp using manual, so that the igniter doesn't have to be used heavily.
Shoulder seasons room temp set on auto, to save on pellets.

Good strategy?
 
Acorrding to my dealer, the feed rate only applies when in room temp. Not a factor in stove temp.
 
subsailor said:
Acorrding to my dealer, the feed rate only applies when in room temp. Not a factor in stove temp.

Well he doesn't know the product line he sells very well then. The proper way to set the feed rate in the first place is done in Stove Temp mode. It's in your owners manual.
 
lbcynya said:
Who said the stove has to shut off in room temp mode? Keep the switch in manual and it will reduce heat output to maintain room temp desired without shutting off. Room temp will prevent overshooting on warmer sunny days (wasting pellets). I see no reason to have the stove shut off during the colder part of the winter since some bit of heat is awlays necessary. Room temp, switch on manual works great. You do have to experiment with sensor wire placement to "calibrate" location to actual room temp. Once you find the right spot, let it be. Or, you can ignore the temps on the control dial and simply turn the dial up/down until you find the right temp. Remember that position and you're good to go.

Stove temp, for me is best for shoulder seasons where I run the stove from 4 to 10:30 pm. In that case I run with the switch on auto so the blower runs normally and, no, the stove won't shut off with the switch on auto on stove temp mode.

So it does not matter if you use Stove Temp on Auto? On Manual can you run it on Stove Temp or Room Temp?

Marg
 
Harman Lover 007 said:
subsailor said:
Acorrding to my dealer, the feed rate only applies when in room temp. Not a factor in stove temp.

Well he doesn't know the product line he sells very well then. The proper way to set the feed rate in the first place is done in Stove Temp mode. It's in your owners manual.

Stove Temp mode on Auto or Manual to set right feed rate?

Marg
 
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