XXV heating efficency

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

bill-e

Member
Nov 24, 2013
54
New Hampshire
First, the XXV's body does not get hot like my daughter's PC45 does and I understand why...not complaining.

However, I noticed during this recent cold snap (-18°) when I had the settings at 9/9 that each day the stove's body would get less hot.

When I did my weekly cleaning on Saturday I used a brush similar to this one to clean the heat exchanger which gets quite an ash buildup.

815OFauN0WL._SL1500_.jpg


The difference was like night and day. The XXV's body actually felt significantly hotter than before and I was running at a lower setting.

Now every time I scrap the burn pot I also use the brush on the heat exchanger directly behind the flames to remove the ash daily.

Another thing I noticed was I could never get the pellets to fill up or overflow the burn pot, at maximum setting they were still well over an inch behind the edge of the burn pot. Obviously I don;t want to overflow the burn pot but I would have liked to try to squeak more heat out of the stove.
 
Yet ANOTHER post that proves that "A clean pellet stove is your friend!"
What do you have your feed control set at & what are you burning for fuel?
 
I had mine cranking close to seven with burn rate a little past 4 last week. The body was pretty hot, could touch it, but didn't want to for long, thats for sure. Your right, clean stove is much hotter, especially after cleaning exaust.
 
I normally run Temp Mode of 70° and feed rate at 4. Honestly, other than not reducing the heat because I was running the temp at 9, the feed rate at nine made no noticeable difference in either flame height or the amount of pellets in the pot. It did use more pellets so it made a difference, I just didn't see it.

I'm burning Jaffery NE Pellets. I now know need to clean the stove heat exchanger more than once a week. I did the bigger clean of blowers and flue at that time as well and things weren't that dirty. It's the ash build up on the heat exchanger and fire box that seemed to make a big difference.
 
If you are doing room temp mode, feed setting will not matter. Only comes into play during stove temp mode.
I started with 9/9 in Stove temp but the heat generated in Room Temp mode is greater. It was my understanding that the feed rate in Room temp set the maximum feed rate that the stove might use and since I had the Temp at 9, I assumed it would keep ramping up the feed rate trying to get to the temperature.
 
even on the coldest days here 120ish so far my XXV has hauled the mail @ 70/75 blower on low i have a three bedroom Log Home Ive never been happier and clean the stove every third week
My XXV isn't big enough or located in the right place to heat my house. With temps in the teens it keeps my house at about 60 (other than the stove room). When temps dropped to single digits and below my furnace had to help.
 
If you are doing room temp mode, feed setting will not matter. Only comes into play during stove temp mode.
That is incorrect. Please read the Harman sticky at the top of the page or the link in my sig. It will save me from typing it for the umpteenth time.
 
  • Like
Reactions: P38X2
I started with 9/9 in Stove temp but the heat generated in Room Temp mode is greater. It was my understanding that the feed rate in Room temp set the maximum feed rate that the stove might use and since I had the Temp at 9, I assumed it would keep ramping up the feed rate trying to get to the temperature.
It will, depending on where you have the feed rate set. It shouldn't be any different in RT mode or ST mode. Once you've set it the way Harman wants you to, constantly adjusting it is counter productive.
 
It will, depending on where you have the feed rate set. It shouldn't be any different in RT mode or ST mode. Once you've set it the way Harman wants you to, constantly adjusting it is counter productive.
I usually leave it at 4. But with the sub zero weather I was trying to get more burning pellets into the pot. Turning up the feed rate did not seem to affect that much.

For instance, if I read the manual about adjusting the feed rate until there is an inch of ash before the edge of the pot, I interpret that as meaning that I can probably adjust the feed rate so that there is less than an inch...meaning more pellets in the pot. At a setting of 9 I have just about an inch of ash. It just seemed to me when I read that that one could adjust it too high and overfill the pot and have burning pellets dropping into the ash pan....not on my stove you cant.
 
I usually leave it at 4. But with the sub zero weather I was trying to get more burning pellets into the pot. Turning up the feed rate did not seem to affect that much.

For instance, if I read the manual about adjusting the feed rate until there is an inch of ash before the edge of the pot, I interpret that as meaning that I can probably adjust the feed rate so that there is less than an inch...meaning more pellets in the pot. At a setting of 9 I have just about an inch of ash. It just seemed to me when I read that that one could adjust it too high and overfill the pot and have burning pellets dropping into the ash pan....not on my stove you cant.
Last time I had my Harman P61A on 9 was the day we installed and tested....
90 degrees and climbing downstairs/ 75 upstairs..... No way can I run at those high numbers....feed rate 3 Room temp at 70 and this during 10 degree nites..
[my Harman is a bit oversized for the house I think but Not Complaining at all.]
 
I just keep it on room temp and it will adjust accordingly. feed rate 4 temp set 75......on the coldest nights below 0 I was averaging about
3 lbs an hour......does a great job!
 
Must be nice to be insulated ;)
NOT!!!!!
Have a 90 Year old house just outside Phlia...2 story with full Basement..Plaster walls with only slats/mortar...
no wall insulation except what is outside behind the vinyl siding.....24 Insulated windows is about it..
HarmanP61A is a Beast for heating.......bag/half day of Stove Chows/ 229.00 Ton at HD keeps us 70-72 by choice. Could go much warmer but then it's un-comfortable..for us anyways..
[do have insulation in the Attic.]. forgot..
 
Last edited:
:) I've got you beat! ;) 246 year old house, pane windows, no insulation, just clapboard, walls split between sheetrock and lath and plaster. stone foundation, mostly uninsulated crawlspace. Normal oil bill to keep the house at 64° is about $4500

We are going to do some renovation this year (I hope) which will probably include windows and some insulation and a stove on the kitchen end of the house.
 
:) I've got you beat! ;) 246 year old house, pane windows, no insulation, just clapboard, walls split between sheetrock and lath and plaster. stone foundation, mostly uninsulated crawlspace. Normal oil bill to keep the house at 64° is about $4500

We are going to do some renovation this year (I hope) which will probably include windows and some insulation and a stove on the kitchen end of the house.
Wow...
that's heck of an oil bill... use to spend 1500.00 yr for oil heat/hot water here/thermostat 66.before pellet stove saved us............yes. u beat our Pants off.......
 
Status
Not open for further replies.