Harman Room Temp not consistent

[NHFlyer]

Hi All,

Long time lurker, but this is my first post. I have been having a great time reading all of the advice and tips here on the forums. Now, to my question: I purchased my Harman P61a earlier this year and have been using on and off over the past few weeks when the temperature is low enough to get away with it! I've been trying to get the settings right in room temp mode (which is what I want to run in). However, no matter what temp I set the stove to, the temperature doesn't remain consistent. I should note that I've extended the temp probe and placed it at about eye height on an inside wall in the room where the stove sits. When I've got the stove in room temp mode, it will heat up and the room will get quite hot (I've got the temp selector set to approx 67, but the room gets into the mid-70s) before the flame simmers down. Finally, the flame will completely die out and the combustion blower will run until the stove is cool and then it will shut down completely. The room will then cool substantially (usually back into the mid-60s) and the whole process will repeat itself. My understanding is that room temp mode should try to keep the temp within 1 degree or so of the set temp (yes, I understand that the setting on the nob might not match exactly the temp in the room and I have no problem using an offset on the temperature selector nob). Has anyone heard of this type of issue? Any advice would be greatly appreciated as I don't like being sweated out of the room on a regular basis!! Thanks!

 

[Justin M]

Sounds like it could just be a big stove with a small heat load. It might get better when it gets colder out.

 

[bags]

Welcome! I have the 68 and just installed it Saturday. I have similar situation so I will watch your thread. The Harman peeps will show up here and help out.
Again, Welcome. You came to the right place.

 

[Justin M]

To expand upon what I said earlier - If your stove is oversized for you application then it may not work well in the shoulder season. In the time that the stove starts up, gets up to operating temperature, satisfies the t-stat, and completes the shut down cycle it puts out a minimum amount of BTUs. If the minimum amount of BTUs is greater than the heating load then the room will be over heated. If this is the situation it will improve as it gets colder out and the heating load increases beyond the minimum BTU output. Another thing to consider is positioning the temperature sensor so that the probe is not touching the wall and being affected by its thermal mass.

 

[bags]

To expand upon what I said earlier - If your stove is oversized for you application then it may not work well in the shoulder season. In the time that the stove starts up, gets up to operating temperature, satisfies the t-stat, and completes the shut down cycle it puts out a minimum amount of BTUs. If the minimum amount of BTUs is greater than the heating load then the room will be over heated. If this is the situation it will improve as it gets colder out and the heating load increases beyond the minimum BTU output. Another thing to consider is positioning the temperature sensor so that the probe is not touching the wall and being affected by its thermal mass.

Makes sense, Justin
I think the best way to handle the issue would be wiring up to a thermostat outside of the room the stove is in.(??) I am not very concerned as long as I have heat when I need it. I can always get up and adjust it myself for now. My probe is hanging down off the rear of the stove about 7" from the floor. That is where the dealer an HVAC guy told me it would work fine. He heats his home and his shop with both with P68's.

 

[JDenyer236]

X2 on what Justin M had said. Once the weather gets colder your temps will be more consistent. Because your stoves minimum output is around 8000 btus it's really not oversized per say but it takes a fair amount of pellets to ignite and get the stove up to temp. A lot of heat gets stored in the stoves thermal mass and this is given up during cool down
and raises the rooms temp higher that what it's set to. This is all normal and once we get out of the shoulder season your temp control will be much more accurate.

 

[bags]

My stove is not within 1 degree but it is kicking on 70 and off at 73. So I am not complaining at all. This reading is coming off of my digital central system stat.

It does get warmer in the room where stove is located and that is to be expected.

NHFlyer, Have you done readings a little away from your stove when it cycles?

 

[New Hampshire Jim]

I would put a thermometer next to the tip on the temperature probe to see If there Is a difference In the temp there and at the spot where you are taking your readings from. probe may be in a draft? Mine is set at 70 Deg. and I get a + or- of 2 when It Is cold out. Its a little hard to set when Its 50 Deg. out

 

[Big papa]

Hi All,

Long time lurker, but this is my first post. I have been having a great time reading all of the advice and tips here on the forums. Now, to my question: I purchased my Harman P61a earlier this year and have been using on and off over the past few weeks when the temperature is low enough to get away with it! I've been trying to get the settings right in room temp mode (which is what I want to run in). However, no matter what temp I set the stove to, the temperature doesn't remain consistent. I should note that I've extended the temp probe and placed it at about eye height on an inside wall in the room where the stove sits. When I've got the stove in room temp mode, it will heat up and the room will get quite hot (I've got the temp selector set to approx 67, but the room gets into the mid-70s) before the flame simmers down. Finally, the flame will completely die out and the combustion blower will run until the stove is cool and then it will shut down completely. The room will then cool substantially (usually back into the mid-60s) and the whole process will repeat itself. My understanding is that room temp mode should try to keep the temp within 1 degree or so of the set temp (yes, I understand that the setting on the nob might not match exactly the temp in the room and I have no problem using an offset on the temperature selector nob). Has anyone heard of this type of issue? Any advice would be greatly appreciated as I don't like being sweated out of the room on a regular basis!! Thanks!

I moved my temp probe into the hall way leading out of the living room beside the furnace thermostat here it is away from direct airflow from the stove and the convection of the stove.in room temp auto it always heats a little warmer as it shuts down.if you put the stove in room temp manual it will hold that exact temp won't heat up to far or let the room cool.it will adjust the fans and flame and hold that 1 degree temp.just make sure you have your temp probe in a good spot and you will be amazed

 

[NHFlyer]

Hi Everyone,

Thanks for the quick and informative replies. I'm new to pellet stoves, so still trying to feel everything out. I originally had the temp probe hanging down from the back side of the stove, a few inches off the floor, not touching anything else, and away from the heat of the exhaust and sides of the stove. However, I found that the heat from the stove was naturally heating from the ceiling down and thought that because the probe was close to the floor it was not getting an accurate reading. So, I extended the temp probe and located it next to the casing of an doorway opening to the rest of the downstairs of the house and secured it at about eye level, not touching the wall. This location is about 15 feet from the stove and free from any drafts. I have used a thermometer and took readings at several locations through the living room which is where the stove is located. The readings were consistent in the living room. A little more info about the layout of the house: it's a center-entrance colonial, approx 1900 sqft. The stove is located in the front-to-back living room (about 12' X 25', standard ceiling height). There are two doorways (no doors, just an opening) to the rest of the downstairs, the one nearest the stove where the temp probe is now located leads to a hallway to the other side of the house where a front-to-back kitchen/dining room is - about the same size as the living room. The other opening at the front of the house leads to a foyer with the staircase to upstairs and another doorway opening to the dining room / kitchen. All-in-all, about 800 sqft on the downstairs.

I was thinking along the same lines as Justin about the limited heat-load, especially in the smallish living room when the outside temperature is in the upper-40s to lower-50s. The P61a is a beast and puts out quite a bit of heat, and right now I'm only looking to bring the inside temp up a little bit. I like the thought of running the stove in room temp - manual mode to keep the maintenance fire burning and stove warm between calls for heat. I was also considering running in low stove temp - manual, but I'm worried about creosote buildup when running the stove at relatively low temp for long periods. I also don't want to be burning pellets continuously this time of year - it's only October for crying out loud!. I'd be fine with +/- a couple of degrees, but +/- 8 to 10 is not going to cut it. After reading everyones' posts, I feel better and am convincing myself that when we get to the real cold weather, the temp will even out.

Do you all run your stoves with different settings depending on the season?

 

[Harman Lover 007]

NHFlyer, welcome to the forum. There are numerous Harman owners here (and a couple of Techs) who are eager to help. I think you need to wait a bit, as others have suggested, to get a real feel for what your new stove will do for you. It really isn't cold enough yet. A couple of suggestions if I may....click on the link in my signature and read that document. Go grab a cold one and come back and read it again. It will help you immensely in understanding your Harman. Also, do a search for "Harman room temp/stove temp" here. THAT will keep you busy!!

 

[bags]

I have been playing around with mine and experimenting. Trial and error. Figuring out what works better and what does not. Also asking questions. A lot of questions! The more specific the better. I think it has been insightful. Getting to know the stove and it's operation and tendencies helps you to make adjustments that suit your needs. At first I was getting big temp swings as well. Along with using many more pellets. You have to be smarter than your smart stove. What makes this a little harder is the fact the stove thinks for itself to a large degree and can change somewhat complicating the pellet totter's mind (yours and mine). It's operation will vary with different modes and settings adding to the frustrating enjoyment of your exploration, LOL!

As for the settings I'll admit that I am still fairly lost but know I am heading in the correct direction now at least. Many do switch things up depending on temps and needs. There are some good common suggestions and things people have found to work. It is personal preference and personal needs mainly. I have seen and read a pretty vast array on this topic. Like a finger print, everyone's is different. They depend on so many variables it is hard to say here is where you need to set it and do this or that. Every home is different. Installation locations vary, temps (in / out), what one person defines as a comfortable, pellets type, on & on. I kept dicking around with the feed rate totally screwing myself. Followed a very common set it at 4. Solved my biggest problem instantly. That's why #4 is a different color. Harman engineering figured it out for us.

Eventually, after reading none stop and then doing it again I noticed a some more common patterns to an extent and started beating those drums. Things got even better. This also applies to answers you get to your questions. Ask as many as you want. Don't be shy about it. No need to reinvent the wheel. That is why many hang here because they were all in our shoes probably ready to kick their stoves at times. They give help and advice very freely. It's a non-stop learning process in the pellet world I've noticed. Look at all of the discussion on pellet brand quality alone. Again, I came to some common conclusions on what will work and what to avoid even if they are cheap. What works for others will likely work for you but there are variables to this also. Different brands available in different areas for pellets. I'm lucky. Somersetts are everywhere here and reasonably priced for example. It is abundantly clear here that everyone likes their Setts so that's what I'm heating with. I might think they suck but it is highly doubtful. No one here has led me astray yet.

Try out what is working for others and what they like. Most opinions here are worth their weight. This is where the common variables are found. Things that work for the masses that get tweeked to personal preferences. One thing I do know regarding HVAC (pellet stove or not) it is all about moving air around which balances things out. Balancing the positive and negative pressures (hot spots and cold spots) and gains vs. loss. Once this is close and your heat is more evenly distributed then work on the temp that you like for your situation.

Another thing I did was locating fans around in different areas and using ceiling fans. I found that putting a box fan close to the stove and blowing the radiant heat away to an extent has helped me get where I want to be tremendously. Works for me, might not for you but it likely will. Do I want to listen to another fan while watching TV? Not really, but the TV's volume goes up and I'd rather be comfy. Not sweeting one minute and shivering the next. It has evened the house out temp wise and there is not much difference throughout. I'm becoming more content by the minute.

I also lurked for a long time but now it's game on and time to fine tune. Good luck! Do you have a central / primary HVAC system? Have you tried distributing and moving the air that way for more constant temps with the fan? Most stats will switch into a fan only mode and just circulate air inside the home. I did and it helped a lot. Now I have that off and am doing what I need with two 20 inch cheap box fans and three ceiling fans. Works great! It took some time, frustration, re-doing, and numerous questions for me to get to this point.