New Lopi won't heat room

[JackVB]

I purchased a Lopi Answer Nextgen insert in October & had it professionally installed complete with stainless steel stovepipe. It is rated to heat up to 1200 sq feet with EPA tested BTUs of 12,129 to 59,527 and an overall efficiency of 72.4%. I have used it approximately 30 times since purchasing it and have been unable to raise the ambient temperature from 69 degrees to past 71 degrees in the approximately 400 sq foot interior room where it is located. The thermometer I am using is approximately 10 feet from the stove at 3 feet off the floor. I have tested it and it is accurate. I set my fire using wood at 13-14% humidity measured with a moisture meter provided with the stove. I fill the box half full and get the first strongly burning (damper full open) and then load it and get the remainder fully engaged before closing the damper 3/4 with the temperature on the door at about 400 to 450 degrees (measured with infrared thermometer). I have also tried keeping the fire box full, damper fully open with a raging fire. I have a built-in fan on the stove that comes on when it reaches 135 degrees and I put this on full. My dealer sent the installer back out to re-check the installation and he said it is fine. The dealer came out and personally tested the wood moisture (13%) and the methodology I used to set my fire. The temperature outside was about 41 degrees and the stove brought the temperature in my room from 69 to 71 in about 1 1/2 hours-no higher. He said I was used to a bigger stove and intimated I was expecting too much. His solution is to sell me a larger Lopi insert. For 41 years I used an old Craft Stove insert that raised the temperature in the same room to 80 degrees if I got the fire too hot. This is an interior room with a floored attic (insulated) above and insulation in the floor below. The exterior windows in the surrounding rooms are all Anderson double-paned, likewise insulated. The house itself is all brick, well-insulated.
My question: am I expecting too much of this insert to raise the temperature to about 75 degrees in a 400 sq foot room? Am I using the insert properly? Any reasonable suggestions appreciated!

 

[bholler]

I purchased a Lopi Answer Nextgen insert in October & had it professionally installed complete with stainless steel stovepipe. It is rated to heat up to 1200 sq feet with EPA tested BTUs of 12,129 to 59,527 and an overall efficiency of 72.4%. I have used it approximately 30 times since purchasing it and have been unable to raise the ambient temperature from 69 degrees to past 71 degrees in the approximately 400 sq foot interior room where it is located. The thermometer I am using is approximately 10 feet from the stove at 3 feet off the floor. I have tested it and it is accurate. I set my fire using wood at 13-14% humidity measured with a moisture meter provided with the stove. I fill the box half full and get the first strongly burning (damper full open) and then load it and get the remainder fully engaged before closing the damper 3/4 with the temperature on the door at about 400 to 450 degrees (measured with infrared thermometer). I have also tried keeping the fire box full, damper fully open with a raging fire. I have a built-in fan on the stove that comes on when it reaches 135 degrees and I put this on full. My dealer sent the installer back out to re-check the installation and he said it is fine. The dealer came out and personally tested the wood moisture (13%) and the methodology I used to set my fire. The temperature outside was about 41 degrees and the stove brought the temperature in my room from 69 to 71 in about 1 1/2 hours-no higher. He said I was used to a bigger stove and intimated I was expecting too much. His solution is to sell me a larger Lopi insert. For 41 years I used an old Craft Stove insert that raised the temperature in the same room to 80 degrees if I got the fire too hot. This is an interior room with a floored attic (insulated) above and insulation in the floor below. The exterior windows in the surrounding rooms are all Anderson double-paned, likewise insulated. The house itself is all brick, well-insulated.
My question: am I expecting too much of this insert to raise the temperature to about 75 degrees in a 400 sq foot room? Am I using the insert properly? Any reasonable suggestions appreciated!

Well first off fill the firebox instead of just half way.

Did they install an insulated blockoff plate?

How tall is the liner and is it insulated

 

[JackVB]

Firebox is full after initial 20-30 minute "startup" . Stove front reaches 450 degrees. That seems pretty hot.
What is insulated blockoff plate?
Liner is approximately the height of one story house - about 20' ? Liner not insulated but chimney is recently completely re-lined.

 

[JackVB]

Firebox is full after initial 20-30 minute "startup" . Stove front reaches 450 degrees. That seems pretty hot.
What is insulated blockoff plate? No- looked and there is no blockoff plate
Liner is approximately the height of one story house - about 20' ? Liner not insulated but chimney is recently completely re-lined.

 

[begreen]

450 above the door is not particularly hot. 700º would be hot.

 

[JackVB]

450 above the door is not particularly hot. 700º would be hot.

Do I need to get the temp to 700 degrees to raise the 400 sq feet room more than 2 degrees?

 

[begreen]

The dealer is right in that the Answer is a small insert vs the large old Craft insert.

I would try for somewhere around 550-600º. That should make a difference. If this is in an exterior wall chimney then a blockoff plate would help as would some insulation behind the insert if there is room.

Does this room have a very high ceiling? Does it have a large opening into other parts of the house?

 

[JackVB]

The dealer is right in that the Answer is a small insert vs the large old Craft insert.

I would try for somewhere around 550-600º. That should make a difference. If this is in an exterior wall chimney then a blockoff plate would help as would some insulation behind the insert if there is room.

Does this room have a very high ceiling? Does it have a large opening into other parts of the house?

The room is interior so the chimney is in the middle of the house and is brick with new liner (8 years old. The ceiling is 9'. The room is a central den and has 4 doorways to other parts of the house but I thought with a rating of 1200 sq feet heating capacity, it would easily be able to heat a simple 400 sq ft room. If I have to heat the fireplace to 550-600, I will be feeding the firebox continuously to maintain that heat level. This is very disappointing for a stove that I simply wanted to raise the temp from the heat pump ambient temp of 69 to about 74-75 degrees. I gather from what you are saying, a smaller insert must be in an enclosed room to be efficient. Wish they had told me that when I bought it! Thanks

 

[kennyp2339]

Small stoves usually disappoint, between the advertised btu output and the square footage they fall short due (alonst a hoodwink) to the shorter burntimes with higher end btu output, I will always recommend going no lower then a 2cu ft stove, especially on a epa re-burn stove, even with a 2cu ft stove you maximum "in the zone" burn time is really only 4-6hrs, the hour before that and the back end 2hrs of coaling stage doesnt provide the heat that people deem useful for there space, unless the live in a super insulated air tight home (like +r35 walls and +r50 attic insulation w/ new triple pane windows)
Some things you can do to improve your heat output, take the surround off, install a block off plate in the smoke shelf area with fireproof insulation above to help keep the heat from rising up your flue, consider selling the stove and buying a larger insert, one that can stick out into the living space better if you have the proper hearth clearances.

 

[JackVB]

Small stoves usually disappoint, between the advertised btu output and the square footage they fall short due (alonst a hoodwink) to the shorter burntimes with higher end btu output, I will always recommend going no lower then a 2cu ft stove, especially on a epa re-burn stove, even with a 2cu ft stove you maximum "in the zone" burn time is really only 4-6hrs, the hour before that and the back end 2hrs of coaling stage doesnt provide the heat that people deem useful for there space, unless the live in a super insulated air tight home (like +r35 walls and +r50 attic insulation w/ new triple pane windows)
Some things you can do to improve your heat output, take the surround off, install a block off plate in the smoke shelf area with fireproof insulation above to help keep the heat from rising up your flue, consider selling the stove and buying a larger insert, one that can stick out into the living space better if you have the proper hearth clearances.

Thank you Kenny- you are telling me what I suspected but no one is saying. I appreciate the advice on the larger insert- it also reinforced my decision to "move up". Again-Thanks!

 

[JackVB]

Thank you Kenny- you are telling me what I suspected but no one is saying. I appreciate the advice on the larger insert- it also reinforced my decision to "move up". Again-Thanks!

One more follow-up to those who have been good enough to help me on this, I asked my installer about the blockoff plate and her responded, "I install ceramic wool at the top and mortar the liner in place to the flue tile. This makes it so heat doesn't escape up the flue and keeps the stainless steel liner warm."

 

[brickie]

Does your insert have a blower?
There is a marked difference in warming the room between 450 and 650.

 

[JackVB]

Does your insert have a blower?

Yes

 

[kennyp2339]

"I install ceramic wool at the top and mortar the liner in place to the flue tile. This makes it so heat doesn't escape up the flue and keeps the stainless steel liner warm."

Yea thats garbage when you consider how much masonry absorbs heat, plus the actual R factor of ceramic insulation compared to rock wool is night and day, rock wool being a lot denser, if you add the (2) factors together of her rational, the tiny bit of ceramic insulation on the top plate (anchor plate for the liner) does nothing because of the 600 deg flue gas going through and conducting out of the liner being absorbed into the masonry, another reason why an insulated liner is best practice.

 

[DBoon]

I have a Lopi Answer and I will counteract all the advice you may get on this site to "go bigger". The problem is likely not the stove - save your money on the trade in because the second stove will likely not do any better until you figure out how to optimize what you have (which won't cost anything).

First, the reality is that you are in Virginia Beach, VA. It is not that cold there. I am in Central NY. It gets plenty cold here. I have a 1250 square house, well-insulated, but only to the extent that a 1922 house can be well-insulated. The windows are original double-hung (and big with lots of them, so lots of heat loss) with storm windows on them but still lots of uninsulated window weight pockets. I have my Answer stove in a fireplace alcove and it uses a blower. The fireplace has an outdoor chimney and there is no block-off plate and the liner is uninsulated and only about 13' tall. There is a block off at the top of the chimney. The Answer stove and insert are really not that different in construction, so I think most of what I tell you is very relevant.

Can the Answer do the job in this house? Yes. It keeps the front half of the house at a comfortable 70 degrees all the time (or higher - 73 or so if it is 40 degrees outside) with the back of the house at 64 (where the bedrooms are, we like it that way). When it gets below 25 degrees outside or so, we augment it a bit with our oil boiler for the back of the house. Just this morning, it warmed the front half of house up from 64 to 70 degrees when it was 25 degrees outside using a load of Cherry (not a high BTU wood) without the boiler running (back of the house warmed from about 60 to 64). That means it is putting out a lot of heat. If I had loaded it with hickory, it probably would have gotten up to 72 or 73. I'll reload about Noon or 1pm after a 7 hour burn (I increase the air a bit with the Cherry to make it burn a little hotter for a shorter period of time).

So if someone tells you that you need a bigger stove, I would say you don't and I'm the one with the small stove in a colder climate than your own and it works for me. A block-off plate or insulated liner might help, but that is not going to likely solve your problem. If your glass is only 450 degrees, I hate to break the news to you but your wood is likely not dry enough. My first year I thought my wood was dry enough and it wasn't and I struggled to really get the stove to work. By year 2 it was a lot better and year 3 with really good, dry wood (dried two or more years) I was good to go.

I would not run the fan on high - keep it on low. If you run it high at the temps you are getting, you are cooling the firebox off too much.

If you are loading the firebox half full and then filling it a half hour later, I can only imagine that your definition of half full or full is a lot different than mine. "Full" is stuffed full, with four or five big splits that won't burn too fast, packed together pretty tightly. You might need to get a pair of two foot long welder's gloves to get the wood fit in there really well (I don't see how I could fill my stove without those gloves). My wife babies the stove and leaves it 3/4 empty - that is not the way to run this stove if you want heat and not just ambience. Don't worry - this is a well-made, very tough stove. It can deal with a packed firebox.

If stuffed full and turned down to 1/4 air (3/4 restricted) you are still not getting heat, then it is most likely that your wood is nowhere near 13-14% moisture content. If you have it turned down to 3/4 air (1/4 restricted) then that tells me that you are giving it too much air, probably because your wood is too wet and it needs that much air to burn. If that is the case, then you are losing all your heat trying to dry your wood out as you burn it. What wood are you burning and where did you get it from and how long have you had it?

 

[bholler]

One more follow-up to those who have been good enough to help me on this, I asked my installer about the blockoff plate and her responded, "I install ceramic wool at the top and mortar the liner in place to the flue tile. This makes it so heat doesn't escape up the flue and keeps the stainless steel liner warm."

If they had insulated the liner like they should have that would keep the stainless warm. And sealing the top doesn't mean the heat can't get up there

 

[begreen]

@DBoon thanks for weighing in. I was hoping for a long-time Answer owner to help here. Our next-door neighbors have an older Answer insert. It's not a heat monster, but it does heat the core of their open floorplan reasonably well. But they burn rarely, mostly during power outages.

@JackVB As a test, close off the doors to the stove room and see how long it takes to warm up the room to say 75º. Then, tape an 18" length of toilet paper to each door lintel. One at a time, open a door and watch the toilet paper. If it pulls strongly into one area that is most likely where the heat is going. You may find with all doors open that the draw is fairly equal, but I suspect one area, possibly that connects to the upstairs stairwell, will pull the hardest.

Are there any openings upstairs like an attic door or a ceiling vent to the attic? Any leaky windows on the second floor?

 

[JackVB]

@DBoon thanks for weighing in. I was hoping for a long-time Answer owner to help here. Our next-door neighbors have an older Answer insert. It's not a heat monster, but it does heat the core of their open floorplan reasonably well. But they burn rarely, mostly during power outages.

@JackVB As a test, close off the doors to the stove room and see how long it takes to warm up the room to say 75º. Then, tape an 18" length of toilet paper to each door lintel. One at a time, open a door and watch the toilet paper. If it pulls strongly into one area that is most likely where the heat is going. You may find with all doors open that the draw is fairly equal, but I suspect one area, possibly that connects to the upstairs stairwell, will pull the hardest.

Are there any openings upstairs like an attic door or a ceiling vent to the attic? Any leaky windows on the second floor?

The upstairs has one door at the head of the stairwell that is closed all the time- no one goes up there. There are no doors to the room with the wood stove, just 4 entrances. There have been a lot of very interesting & informative comments but I find it odd that this wood stove insert cannot heat a thermometer 10' from the stove more than 2 degrees (from 69 to 71) with the wood stove fully engaged for an hour or more. 71 degrees is the highest we have been able to heat the room and that is with 53 degrees outside!!

 

[JackVB]

I have a Lopi Answer and I will counteract all the advice you may get on this site to "go bigger". The problem is likely not the stove - save your money on the trade in because the second stove will likely not do any better until you figure out how to optimize what you have (which won't cost anything).

First, the reality is that you are in Virginia Beach, VA. It is not that cold there. I am in Central NY. It gets plenty cold here. I have a 1250 square house, well-insulated, but only to the extent that a 1922 house can be well-insulated. The windows are original double-hung (and big with lots of them, so lots of heat loss) with storm windows on them but still lots of uninsulated window weight pockets. I have my Answer stove in a fireplace alcove and it uses a blower. The fireplace has an outdoor chimney and there is no block-off plate and the liner is uninsulated and only about 13' tall. There is a block off at the top of the chimney. The Answer stove and insert are really not that different in construction, so I think most of what I tell you is very relevant.

Can the Answer do the job in this house? Yes. It keeps the front half of the house at a comfortable 70 degrees all the time (or higher - 73 or so if it is 40 degrees outside) with the back of the house at 64 (where the bedrooms are, we like it that way). When it gets below 25 degrees outside or so, we augment it a bit with our oil boiler for the back of the house. Just this morning, it warmed the front half of house up from 64 to 70 degrees when it was 25 degrees outside using a load of Cherry (not a high BTU wood) without the boiler running (back of the house warmed from about 60 to 64). That means it is putting out a lot of heat. If I had loaded it with hickory, it probably would have gotten up to 72 or 73. I'll reload about Noon or 1pm after a 7 hour burn (I increase the air a bit with the Cherry to make it burn a little hotter for a shorter period of time).

So if someone tells you that you need a bigger stove, I would say you don't and I'm the one with the small stove in a colder climate than your own and it works for me. A block-off plate or insulated liner might help, but that is not going to likely solve your problem. If your glass is only 450 degrees, I hate to break the news to you but your wood is likely not dry enough. My first year I thought my wood was dry enough and it wasn't and I struggled to really get the stove to work. By year 2 it was a lot better and year 3 with really good, dry wood (dried two or more years) I was good to go.

I would not run the fan on high - keep it on low. If you run it high at the temps you are getting, you are cooling the firebox off too much.

If you are loading the firebox half full and then filling it a half hour later, I can only imagine that your definition of half full or full is a lot different than mine. "Full" is stuffed full, with four or five big splits that won't burn too fast, packed together pretty tightly. You might need to get a pair of two foot long welder's gloves to get the wood fit in there really well (I don't see how I could fill my stove without those gloves). My wife babies the stove and leaves it 3/4 empty - that is not the way to run this stove if you want heat and not just ambience. Don't worry - this is a well-made, very tough stove. It can deal with a packed firebox.

If stuffed full and turned down to 1/4 air (3/4 restricted) you are still not getting heat, then it is most likely that your wood is nowhere near 13-14% moisture content. If you have it turned down to 3/4 air (1/4 restricted) then that tells me that you are giving it too much air, probably because your wood is too wet and it needs that much air to burn. If that is the case, then you are losing all your heat trying to dry your wood out as you burn it. What wood are you burning and where did you get it from and how long have you had it?

Oak cut on my property, split and stored in enclosed woodshed 2 years. Used a moisture meter, fireplace salesman came out, split a piece of my wood & tested it. 13.5% moisture. I have tried 1/4 restricted, 3/4 restricted, full open, full closed. Nothing changes the outcome.

 

[begreen]

The upstairs has one door at the head of the stairwell that is closed all the time- no one goes up there. There are no doors to the room with the wood stove, just 4 entrances. There have been a lot of very interesting & informative comments but I find it odd that this wood stove insert cannot heat a thermometer 10' from the stove more than 2 degrees (from 69 to 71) with the wood stove fully engaged for an hour or more. 71 degrees is the highest we have been able to heat the room and that is with 53 degrees outside!!

How many sq ft is the house? Try the toilet paper test.

 

[DBoon]

If they had insulated the liner like they should have that would keep the stainless warm. And sealing the top doesn't mean the heat can't get up there

Agreed, bholler, both those things are the right thing to do and I wish my install had them. I learned a lot from this site since my first (current) install (much from you - thanks again) and my new (currently renovating) house has a block off plate insulated above with rockwool and an insulated liner (again, thanks for your advice and comments on that install).

Having said that, my Lopi Answer with a subpar installation still puts out a lot of heat. It's 10 degrees out right now, the Answer has been keeping the front half of my house at 70 degrees for the last few hours (23 degrees at 7:30pm when I reloaded), the Answer is cruising at 500-550 stovetop since 8:30pm (the last hour) and will continue on that pace with it's full load of big hickory splits until 11:00pm or so (it will probably peak at 600 degrees about 10pm). Meanwhile, the back half of the house has been maintained at 64 degrees since the stove reload at 7:30pm. The high today was 28 and I've burned a half gallon of oil in my boiler to take the edge off the back of the house in the morning.

The whole scenario will repeat tomorrow. Max 1/2 gallon to 1 gallon of oil during 24 hours when the high will be around 30 degrees and the low overnight about 10.

Yeah, I wish I had a better install, but the Answer does the job.

Oak cut on my property, split and stored in enclosed woodshed 2 years.

Oak, like hickory, takes a long time to dry out. If the woodshed is enclosed and doesn't permit air movement, it is likely nowhere near dry enough. I've found that wood moisture meters do a poor job of measuring real moisture content of woods like hickory and oak. Reference this thread https://www.hearth.com/talk/threads/using-a-multimeter-to-measure-wood-moisture-level.40033/ and see if you get a different result for moisture content. It took my hickory more than two years covered on top and drying outside exposed on the sides to really become dry enough to perform well in the stove. More than likely, your oak is just not dry enough to make your stove really perform the way it should.

 

[SuperGenius]

I’m with with DBoon regarding the wood. Maybe try a few bundles of kiln dried or heat treated wood as a test. I was completely dejected when I first tried my insert and couldn’t get any useful heat until I found out my “seasoned” wood wasn’t. I’ve never met a modern insert that couldn’t heat one room. Usually, it’s a challenge to spread the heat elsewhere.

 

[MegCog]

JackVB, did you ever figure this out? I am having issues very similar to yours with my new wood stove insert and I have been wondering if it could be due to an air leak or overdraft. The installers broke my glass bringing the stove in and, now that they’ve installed the new glass, I definitely have an air leak in between the glass and the gasket so wondering if that could explain my (and your?) problem....

 

[Silversniper]

You have probably seen my long thread on the Lopi Flushwood next gen where I had similar issues. I had extremely dry Aussie hardwood, but I believe the heat output from the wood varies a lot for reasons aside from its dryness. I can’t be scientific about it, but we’ve always had variable outcomes.

The cheapest way to test this theory is to grab a few different samples from different suppliers, and see if you get improvements.

Another thing to test is whether the damper is fully closing - another Lopi thread talks about giving it a really hard shove.

I also found a block off plate made a big difference.