Maximum stove body heat on a PelPro PPC90 when in HI mode

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PelPro PPC90

New Member
Nov 18, 2021
15
04756
I've got this PelPro PPC90 that I hate, but I'm too cheap to throw it out and buy a fancy Harmon!

I'd like to know from an "Expert" what should be the maximum allowable temperature on the top of the stove when it is operating in HI mode (uncontrolled mode).

This stove is different than most. It has a cast iron inner stove chamber and an outer metal skin. The outer skin doesn't get too hot to touch when burning in normal (thermostat controlled) mode. However, when the stove is put in HI mode, the stove can generate a frightful amount of heat.

I have a fancy Klein Tools infrared thermometer gun and I use it to monitor and learn how the stove heats up.

The top temperature setting in normal thermostat mode is 84F. The stove shuts down when the internal temperature thermometer reaches 86F and restarts when the temperature drops to about 81F.

When the stove is in HI mode, there doesn't seem to be a maximum safe limit.

With the below zero outdoor temps we have been having, I have been running the stove on HI for about 20 minutes or so, and then manually dropping the temp control back to 84F in normal mode . I don't feel the high temps on HI mode are safe and may damage the stove body.

What should the maximum allowable temps be on the top and sides and front of this stove when it is operating in "wide open" HI mode?

P.S. I did learn a "trick" that allow me to run on HI for a little while longer.... I change the TRIM setting to -4 while in normal mode, moments before switching to HI mode. This drastically slows down the rapidly climbing temps generated in HI mode ( I usually use a TRIM of +1 (my normal setting)).
 

Mt Bob

Minister of Fire
Oct 31, 2013
4,325
park county montana
You have it backwards. Your top,door and sides(legs) are cast, The stove body is steel.
Obviously it would seem they do not want the stove run at high temps for periods of time, or/and they think why would anyone want a room hotter than low 80's. Why would you?
Don't perhaps have it in a small room, and you have no air circulation to move the air?
One thing you can try, buy the optional thermostat and mount it away from stove,perhaps even in a different room.If stove gets too hot from what the manufacturer wants to see, it would trip the high reset, and stove will not run again until you reset it.
 
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Mt Bob

Minister of Fire
Oct 31, 2013
4,325
park county montana
You have it backwards. Your top,door and sides(legs) are cast, The stove body is steel.
Obviously it would seem they do not want the stove run at high temps for periods of time, or/and they think why would anyone want a room hotter than low 80's. Why would you?
Don't perhaps have it in a small room, and you have no air circulation to move the air?
One thing you can try, buy the optional thermostat and mount it away from stove,perhaps even in a different room.If stove gets too hot from what the manufacturer wants to see, it would trip the high reset, and stove will not run again until you reset it.
 

sweaty

New Member
Dec 13, 2021
46
USA
I've got this PelPro PPC90 that I hate, but I'm too cheap to throw it out and buy a fancy Harmon!

I'd like to know from an "Expert" what should be the maximum allowable temperature on the top of the stove when it is operating in HI mode (uncontrolled mode).

This stove is different than most. It has a cast iron inner stove chamber and an outer metal skin. The outer skin doesn't get too hot to touch when burning in normal (thermostat controlled) mode. However, when the stove is put in HI mode, the stove can generate a frightful amount of heat.

I have a fancy Klein Tools infrared thermometer gun and I use it to monitor and learn how the stove heats up.

The top temperature setting in normal thermostat mode is 84F. The stove shuts down when the internal temperature thermometer reaches 86F and restarts when the temperature drops to about 81F.

When the stove is in HI mode, there doesn't seem to be a maximum safe limit.

With the below zero outdoor temps we have been having, I have been running the stove on HI for about 20 minutes or so, and then manually dropping the temp control back to 84F in normal mode . I don't feel the high temps on HI mode are safe and may damage the stove body.

What should the maximum allowable temps be on the top and sides and front of this stove when it is operating in "wide open" HI mode?

P.S. I did learn a "trick" that allow me to run on HI for a little while longer.... I change the TRIM setting to -4 while in normal mode, moments before switching to HI mode. This drastically slows down the rapidly climbing temps generated in HI mode ( I usually use a TRIM of +1 (my normal setting)).
I have PelPro PP60, which I think is a smaller version of the same stove.

I have ran it on HI but never for too long. No more than one hour for sure. It gets very hot. I don't remember the temperature reading on the stove body but I can tell you that the room the stove is in gets in the low 80s/high 70s quickly and the exhaust and the top are too hot to touch. With yours being a bigger one, I can imagine it being hotter.

It was a little scary at that temperature so I just don't do it much and never without supervision. Besides, the room is not comfortable at all.
 

Jeremy6500

Feeling the Heat
Jan 22, 2021
353
Indiana
I have a PP130. I know there is talk in general that it is not a good idea to run stoves on high for a long period of time since it can warp materials, but I didn't see anything in my PP130 manual addressing this.

I don't ever set mine to run on high continuously. I usually use comfort mode when we are home and will set it on low when we are not.

It does ramp up to high from time to time when it is very cold out, but only for a brief time.
 

Jeremy6500

Feeling the Heat
Jan 22, 2021
353
Indiana
I ran mine on HI for about 45 minutes. The top above the firebox by the vents definitely got warm, but not close to the point where I couldn't touch it.

I believe the stove also has overtemp protections, so if it gets too hot it will shut down.
 

PelPro PPC90

New Member
Nov 18, 2021
15
04756
You have it backwards. Your top,door and sides(legs) are cast, The stove body is steel.
Obviously it would seem they do not want the stove run at high temps for periods of time, or/and they think why would anyone want a room hotter than low 80's. Why would you?
Don't perhaps have it in a small room, and you have no air circulation to move the air?
One thing you can try, buy the optional thermostat and mount it away from stove,perhaps even in a different room.If stove gets too hot from what the manufacturer wants to see, it would trip the high reset, and stove will not run again until you reset it.
I finally was able to talk to a pelpro technician and not one of the secretaries that answer their customer service phones all the time. They told me the the stop limit on the snap disc is 250°. The snap disc is mounted to the side of the auger tube inside the stove behind the heating chamber where all the wires and gadgets are. I use the stove to heat my entire 2300 ft house and I have for years. I own a very old house that has many rooms that are all broken up by walls and small doorways and passing hot air around the entire house is a major problem. We use a double window fan suspended from the top of the doorway from the living room to the dining room. The stove is in the far corner of the living room. We have recently had the longest coldest spell in my 70-year memory. Yes the only way to keep the house warm and stay off the oil was to run the stove periodically on the high mode. When the top surface of the stove in the front, just above the door, is at 135°, the auger tube next to the snap disc is also about the same temperature using my infrared thermometer. That tells me that I have more than a hundred degrees leeway before the stove gets anywhere near the snap discs stop temperature. I am not trying to Max it out anywhere near 250 and actually a 135° top surface temperature is extremely hot and I have no desire to go above that. When the top surface of the stove is at 135°, my LCD display screen says the stove is around 110° , based on the ambient probe temperature which I have always attached to the side of the stove in the back. I don't think there's any stainless steel stove parts and certainly not cast iron parts, that can't withstand a prolonged 135° temperature, so I think I'm good to go.
 

Mt Bob

Minister of Fire
Oct 31, 2013
4,325
park county montana
135f does not seem bad at all. I believe yours is one that has just a hi-lo switch, if so they show no restrictions about running it on hi for long periods. Which would mean they sized the room blower and passageways to handle the heat.
To give you an example, only my Accentra is running at the moment. In hi-lo mode because it is below 0 here. It's on lo, for a while. The top is 180, the sides 200,the air coming out slowly(being on lo burn) is 290. BUT this stove is almost all cast.
Anyway,I would say you are well below the safety limit, and very safe.
 
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PelPro PPC90

New Member
Nov 18, 2021
15
04756
135f does not seem bad at all. I believe yours is one that has just a hi-lo switch, if so they show no restrictions about running it on hi for long periods. Which would mean they sized the room blower and passageways to handle the heat.
To give you an example, only my Accentra is running at the moment. In hi-lo mode because it is below 0 here. It's on lo, for a while. The top is 180, the sides 200,the air coming out slowly(being on lo burn) is 290. BUT this stove is almost all cast.
Anyway,I would say you are well below the safety limit, and very safe.
The PelPro PPC90 does not have a high low switch. It has no switches. There is an LCD panel with four keys for making adjustments by pressing the keys. LO is achieved by dropping the set temperature down to 60 and HI is achieved by raising the set temperature above 84. This stove is sort of a stove within a stove. The interior burn chamber is surrounded by a very large cast envelope that is anywhere from 1 in to 12 in away from the burn chamber and so the outer stove skin is much much cooler to the touch than any other stove that is just a single unit without an envelope. When the stove is in high mode and I direct the infrared thermometer towards the front door and window at the burn pot, I get temperatures in the mid 600s and I've never seen it hotter than that.
 
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Jeremy6500

Feeling the Heat
Jan 22, 2021
353
Indiana
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The 135* sounds perfectly fine to me. Here are pics of the temp right above my door on my USSC stove running on medium and then high. If you think about it, 135* isn’t much. My hot water heater is set over 100*.
 
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PelPro PPC90

New Member
Nov 18, 2021
15
04756
View attachment 291374 View attachment 291375 The 135* sounds perfectly fine to me. Here are pics of the temp right above my door on my USSC stove running on medium and then high. If you think about it, 135* isn’t much. My hot water heater is set over 100*.
Hey, thanks! Your temperature readings are pretty consistent with the ones I've gotten over the last 4 years. I love my Klein Tools infrared thermometer!! I've used it for all sorts of diagnostic things over the years.
 

Jeremy6500

Feeling the Heat
Jan 22, 2021
353
Indiana
Hey, thanks! Your temperature readings are pretty consistent with the ones I've gotten over the last 4 years. I love my Klein Tools infrared thermometer!! I've used it for all sorts of diagnostic things over the years.

I know the Pellet Pro stoves are not high end or fancy at all, but I have been very happy with mine. If I keep it clean it does it’s job well and since it doesn’t have the bells and whistles it is super easy for me to troubleshoot when something goes wrong.

How does using a fan hanging from the ceiling work for moving heat around. I have not done that. I have/do use box fans. I tried both blowing warm air in to other rooms and sucking cold air out of rooms. I have found it works much better pulling the cold air out of areas and blowing it at the stove. This causes the warm air that is higher in the room to circulate in. Since hot air rises I was wondering if a fan up high did well blowing the hot air.
 
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PelPro PPC90

New Member
Nov 18, 2021
15
04756
I know the Pellet Pro stoves are not high end or fancy at all, but I have been very happy with mine. If I keep it clean it does it’s job well and since it doesn’t have the bells and whistles it is super easy for me to troubleshoot when something goes wrong.

How does using a fan hanging from the ceiling work for moving heat around. I have not done that. I have/do use box fans. I tried both blowing warm air in to other rooms and sucking cold air out of rooms. I have found it works much better pulling the cold air out of areas and blowing it at the stove. This causes the warm air that is higher in the room to circulate in. Since hot air rises I was wondering if a fan up high did well blowing the hot air.
I have tried it both ways.... However the living room where the pellet stove is is a pretty small room and there are two adjoining rooms with pretty small doorways so the living room can get pretty darn warm when the stove is set on high. I mean the living room temperature can be 80 or 82 when it's on high. We sit in the living room and watch TV in our shorts and t-shirts on these really cold evenings because we need that really warm temperature in the living room so it will heat the entire rest of the first floor. Since the living room temperature is very warm we have had the best luck using the fan shown in the photo to push that hot air out of the living room into the dining room and other rooms that are joined the dining room which are more open in architecture. That double fan has three speeds and when it's on the highest speed it's kind of loud but it can seriously push some hot air into the joining rooms.

IMG_20220202_190403319.jpg
 

Jeremy6500

Feeling the Heat
Jan 22, 2021
353
Indiana
9A1BABF3-B32B-4123-ABCC-ED7B55D03268.jpeg
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Having the fan high probably helps a lot. My house is an L with a stove at each end. For my setup I have found that blowing cooler air at the stove from the floor works well. The attached pic are down the hall, then around the corner and in to the room with the stove. If I keep the doors open this creates a pretty even heat in that part of the house. I do the same thing at the other end. Blowing cooler air at the stove.

Sorry the pics are rotated. In my library they are not.
 

PelPro PPC90

New Member
Nov 18, 2021
15
04756
View attachment 291382 View attachment 291383 View attachment 291384 Having the fan high probably helps a lot. My house is an L with a stove at each end. For my setup I have found that blowing cooler air at the stove from the floor works well. The attached pic are down the hall, then around the corner and in to the room with the stove. If I keep the doors open this creates a pretty even heat in that part of the house. I do the same thing at the other end. Blowing cooler air at the stove.

Sorry the pics are rotated. In my library they are not.
I think the technical experts would agree with your approach generally. I was a farmer for many decades before I retired. We had large greenhouses which were quite tall. The taller the greenhouse the more effective it was because the upper part of the center of the greenhouse stored heat. We all know he rises but I never realized until I got my first greenhouse that I could store the heat in an upper area if it was trapped. That is what happens in my small living room with the pellet stove. The temperature up near the low ceilings in this Old House can be 25° warmer than 3 ft off the ground because that hot air is just being banked up near the ceiling. I have an extreme excess of warm air in the upper part of the ceiling of that room and anything I can do to exhaust that hot air out of that room will help cool the room down but if I send that hot air into a joining room it heats the adjoining rooms in the house very quickly and efficiently.
 

Jeremy6500

Feeling the Heat
Jan 22, 2021
353
Indiana
I think the technical experts would agree with your approach generally. I was a farmer for many decades before I retired. We had large greenhouses which were quite tall. The taller the greenhouse the more effective it was because the upper part of the center of the greenhouse stored heat. We all know he rises but I never realized until I got my first greenhouse that I could store the heat in an upper area if it was trapped. That is what happens in my small living room with the pellet stove. The temperature up near the low ceilings in this Old House can be 25° warmer than 3 ft off the ground because that hot air is just being banked up near the ceiling. I have an extreme excess of warm air in the upper part of the ceiling of that room and anything I can do to exhaust that hot air out of that room will help cool the room down but if I send that hot air into a joining room it heats the adjoining rooms in the house very quickly and efficiently.

I am a tinker at heart. I can never leave stuff alone. One reason I like pellet stoves is the ability to try different things and figure out what works for your situation.
 

PelPro PPC90

New Member
Nov 18, 2021
15
04756
I am a tinker at heart. I can never leave stuff alone. One reason I like pellet stoves is the ability to try different things and figure out what works for your situation.
Yep, every situation is different and always a challenge. I grew up in an area where there are a lot of large old houses. I mean the houses were 200 to 300 years old or older. Whenever I think of my pellet stove I think of those houses. The pellet stove is a single point source of heat. It's nothing like baseboard heat or forced air heat where there's vents in every room. We get our heat from one small spot in the house and expect it to do magical things. Every single one of those large old houses that I knew in my youth had multiple fireplaces throughout the house. There was no electricity for fans when they built those homes but the rooms were blocked off from each other by small doorways and the entire architecture was very blocky and broken up. They had to have fireplaces everywhere throughout the house and the people that lived there or their hired help had to run around making and tending fires all over the homes through the winter time to make sure the entire house was warm and friendly. My house is fairly small and almost all the exterior wall space is taken up with appliances or countertops or joining rooms etc. I wish I had a safe and good looking spot to put another small pellet stove on the opposite side of the house from where my current one is, but I do not. I have no place to do that at all. But I burn one bag of pellets everyday during this real cold weather and that's pretty low cost heat for such a large home so I guess I'll just try to live with it until somebody invent something better and cheaper. ;) Good luck - it sounds like you are on the right path.