Vermont Castings Montpelier - problem heating space

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The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
Hello Everyone ... my Husband and I recently purchased a VC Montpelier wood burning insert and had it installed by our Chimney guy (who is excellent - he has serviced our 5 fireplaces for the last 2 years + did a liner for our new boiler last year) so I do not think the install is the issue. The insert was installed last week and we spent the end of the week/weekend doing the break-in fires as suggested in the manual. Nothing seems to be overtly wrong; however, it is not producing much heat. We have only used 2yr seasoned hardwood and have tried everything from 1 log at a time to filling it with wood, no change.

Yesterday we closed off the Living Room and Den, our house is an 1897 Victorian so we have either pocket doors or standard doors to be able to close off every room in the house. With the doors closed the space to heat is about 500sqft with 9ft ceilings, we ran the stove from 6am and the warmest the rooms reached by midnight was 72 degrees (it was high 50s/low 60s outside) ... from what our chimney guy told us and from what others have said the space should have been HOT, like 85. Today we ran the stove since 6am and now it is about 9pm, but this time with the doors open (the 1st floor is about 1500sqft and I closed the doors to all of the bedrooms upstairs) the warmest the thermostat read (located in the Den) was 61 and again it was in the 50s outside today. We purchased this to heat our 1st floor so that we could save on oil and only use the boiler to heat the 2nd floor + attic.

I do not see how this will heat anything, even the room it is in, come winter. When you hold your hand in front of the blower vents it is lukewarm/warm-ish ... like a blowdryer on low/warm not high/hot. Even standing right in front of the insert you barely feel any additional warmth, but if you open the door it is too hot to add logs without gloves. The fires are also not lasting anywhere near the 8+hrs VC suggests it would, even with 2 year seasoned oak logs ... more like 4hrs. I have reached out to both our Installer and Dealer, but I have not heard back yet. I would like to know from those that know better what I should address with them or what I suggest they do. Any and all help or suggestions are appreciated and welcomed. This was a HUGE investment for us considering all of the other restoration work we have done and we are SUPER disappointed, feels like we would have generated more warmth burning the $5000 in our fireplace!
 
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begreen

Mooderator
Staff member
Nov 18, 2005
81,852
South Puget Sound, WA
Welcome. Can you explain in detail how the insert is being loaded, with how much wood? Then how is the fire being managed? That is what is the air control setting at the various stages of the fire? Does the fire burn robustly? Is the glass staying clean?

About the installation - Is this an interior or exterior chimney? Was a block-off plate installed? And last, how tall is the liner on the insert?
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,852
South Puget Sound, WA
Was the wood purchased or split and stacked 2 yrs ago on the property in a sunny area?
 

cheapheatnow

Member
Nov 26, 2009
19
WMASS
I have the same unit. I too was unhappy the first year. However, here is what I learned:

Smaller splits improved performance
Beefed up insulation throughout the house
Got used to loading every 4 hours, particularly in the coldest part of winter. I do not get 8 hours of burn time that has useful heat output for the entire 8 hours.
Run the unit hot, don't choke the air down too early...decrease gradually
Put a fan facing the insert on at low speed...this helps move the warm air to other portions of the house

Heats the whole house, 1600 sq foot gambrel 2 story....though on the coldest overnights I do have to run the electric heat upstairs. It is easy to operate, has proven durable...9th season. The fan unit conked out last year...but the replacement runs super quiet. Overall I am pleased and it meets my needs.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
Welcome. Can you explain in detail how the insert is being loaded, with how much wood? Then how is the fire being managed? That is what is the air control setting at the various stages of the fire? Does the fire burn robustly? Is the glass staying clean?

About the installation - Is this an interior or exterior chimney? Was a block-off plate installed? And last, how tall is the liner on the insert?
Thanks so much for your response. First we built a fire with kindling + brown paper, then added smaller split logs and once that took we loaded in larger split wood 2 horizontal and 1 diagonal ... we also tried loading in as much wood as possible once it was going and there was a solid bed of super hot embers and also 1 larger split log at a time. Nothing seems to change the temperature of the blower. We have also tried everything with the damper/air control and no change in blower temperature. It also seems to be going through A LOT of wood. The fire does burn very well and evenly ... when you open the door it is blisteringly hot. The glass is not completely clean, there is some soot around the edges.
The fireplace that the insert was installed into is a corner fireplace with another fireplace in the next room in the same corner ... the exterior wall that it is on is a southern exposure and the chimney is stone, but the fireplace/firebox is brick. Additionally the chimney goes up past our master bath; however the other fireplace that I mentioned has another fireplace in the room above next to our master bath. I do not believe it was block-off plate installed; however, I will check with my installer. I do know that he used a double walled liner and refused to use the liner the Dealer had sold us. The liner is 40ft, we have 9ft ceilings and 3 floors (plus attic) I think I remember them saying that they insulated up at the cap? Hope this helps give you more clarity.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
I have the same unit. I too was unhappy the first year. However, here is what I learned:

Smaller splits improved performance
Beefed up insulation throughout the house
Got used to loading every 4 hours, particularly in the coldest part of winter. I do not get 8 hours of burn time that has useful heat output for the entire 8 hours.
Run the unit hot, don't choke the air down too early...decrease gradually
Put a fan facing the insert on at low speed...this helps move the warm air to other portions of the house

Heats the whole house, 1600 sq foot gambrel 2 story....though on the coldest overnights I do have to run the electric heat upstairs. It is easy to operate, has proven durable...9th season. The fan unit conked out last year...but the replacement runs super quiet. Overall I am pleased and it meets my needs.
Thanks so much for your super quick response :) Will definitely take your advice on the smaller splits ... like I said in my post we have tried everything from smaller splits to large ones that took up the whole space! Today we ran it fully open, thinking if we did not choke down on the air at all it might improve.

I would think regardless of split size that if we kept a roaring fire going that it could heat 500sqft past 72 on a normal fall day?! The room that it is in has all new windows and the house for its age is well insulated.

Curious, how hot does the air feel that comes out of your blowers?
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,852
South Puget Sound, WA
OK, let's assume that the wood is good. The first red flag is the 40ft liner. That is quite tall. It could be that most of the heat was going up the flue. The other problem could be the way that the air control is being set. The way EPA stoves work is a bit counterintuitive. Once the fire is going well, closing down the air supply will actually make the insert hotter. What happens when closing down the primary air is that the vacuum created by the draft will then start pulling air from the secondary manifold and through the burn tubes. That secondary air will lead to more complete combustion and a hotter fire. You will see this as fountains of fire, ideally with a bluish flame, coming from the secondary tubes.

When you start the next fire, once it is starting to burn robustly, close down the air by moving the control to the right until the fire gets lazy. Stop there and let the fire regain strength. Once it is burning robustly again, repeat by moving the air control further to the right. Eventually you should be able to move it all the way to the right and the fire should still recover and get strong but by this time most of the fire may be at the top of the firebox coming from in front of the tubes. The stove should radiate more heat and you should notice hotter air coming from the stove too.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
OK, let's assume that the wood is good. The first red flag is the 40ft liner. That is quite tall. It could be that most of the heat was going up the flue. The other problem could be the way that the air control is being set. The way EPA stoves work is a bit counterintuitive. Once the fire is going well, closing down the air supply will actually make the insert hotter. What happens when closing down the primary air is that the vacuum created by the draft will then start pulling air from the secondary manifold and through the burn tubes. That secondary air will lead to more complete combustion and a hotter fire. You will see this as fountains of fire, ideally with a bluish flame, coming from the secondary tubes.

When you start the next fire, once it is starting to burn robustly, close down the air by moving the control to the right until the fire gets lazy. Stop there and let the fire regain strength. Once it is burning robustly again, repeat by moving the air control further to the right. Eventually you should be able to move it all the way to the right and the fire should still recover and get strong but by this time most of the fire may be at the top of the firebox coming from in front of the tubes. The stove should radiate more heat and you should notice hotter air coming from the stove too.
Thank you! Will try that. Now we have the air intake fully open and it is burning through the wood super fast ... after 2hrs it is burned down to coals and cool embers. Just stirred the embers up and added smaller split wood, 3 pieces. It is just starting to come up. You know, I did point out to my Husband that I thought it was odd that there seemed to be no blue flames even with the fire going strongly.

The unit is also making a bit of noise ... not the blower but creaks and thuds (like with the break-in fires)
 

jatoxico

Minister of Fire
Aug 8, 2011
4,218
Long Island NY
I saw in another thread where you estimated your chimney to be 40'. That's very long. I wonder if you could check that and post again if that's accurate.

I don't know where on the Montpelier would be best but a stove top thermometer placed on center top (in the vent?) so you can get an idea of what temp you're running is always a good idea and a help when discussing/trouble shooting.

As was already mentioned turning down the primary air should help to raise the stoves temp with the caveat; as long as the wood is properly dried. If it's still too wet turning down the air usually leads to a cold smoky fire.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
I saw in another thread where you estimated your chimney to be 40'. That's very long. I wonder if you could check that and post again if that's accurate.

I don't know where on the Montpelier would be best but a stove top thermometer placed on center top (in the vent?) so you can get an idea of what temp you're running is always a good idea and a help when discussing/trouble shooting.

As was already mentioned turning down the primary air should help to raise the stoves temp with the caveat; as long as the wood is properly dried. If it's still too wet turning down the air usually leads to a cold smoky fire.
The 40ft liner is because our chimney is quite tall ... our house has 2 floors + servants quarters + attic, plus high ceilings. I am going to try turning down the air intake and will buy a thermometer. It just does not seem to be hot, it ran ALL day since 6am and the surround and door frame is barely warm to the touch. Thank you!
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,852
South Puget Sound, WA
Thank you! Will try that. Now we have the air intake fully open and it is burning through the wood super fast ... after 2hrs it is burned down to coals and cool embers. Just stirred the embers up and added smaller split wood, 3 pieces. It is just starting to come up. You know, I did point out to my Husband that I thought it was odd that there seemed to be no blue flames even with the fire going strongly.

The unit is also making a bit of noise ... not the blower but creaks and thuds (like with the break-in fires)
You may be able to turn down the air completely pretty quickly once the fire gets rolling. I am concerned about that 40ft stack. The potential for overfiring the stove is there due to too strong draft, especially once it gets colder.
 
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jatoxico

Minister of Fire
Aug 8, 2011
4,218
Long Island NY
To answer your other question, the air coming from the vent of my insert is hot. When cranking it's uncomfortable to keep your hand there.

Please take some pictures. Maybe you and you husband remove the surround so we can see the liner and if there's anything there to stop hot air flowing up the chimney between the liner and the masonry. This is what begreen was asking when h mentioned block-off plate.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
You may be able to turn down the air completely pretty quickly once the fire gets rolling. I am concerned about that 40ft stack. The potential for overfiring the stove is there due to too strong draft, especially once it gets colder.
Had to admit I had to google overfiring lol ... this is what I found: Overfiring a wood stove -- or burning a bigger, hotter fire than you need -- can damage the components of the stove. Over time, this means the stove may weaken. It also means you're spending more money than you need to on fuel. Signs you're overfiring include red-hot stove panels, noisy drafting (a big fire demands a lot of oxygen), and a phenomenon called whuffing, in which the stove actually vibrates on the hearth. If this is correct then I do not think we have ... the stove is never that hot, the drafting isn't really noisy and we have not had any whuffing.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
To answer your other question, the air coming from the vent of my insert is hot. When cranking it's uncomfortable to keep your hand there.

Please take some pictures. Maybe you and you husband remove the surround so we can see the liner and if there's anything there to stop hot air flowing up the chimney between the liner and the masonry. This is what begreen was asking when he mentioned block-off plate.
Not really sure we can remove the surround ... it seems well put in there. Our fireplace opening is taller than the insert so we could take a photo up the chimney to see what is there. I know that they insulated at the cap, but beyond that I am not sure. Honestly ... if you hold your hand above the insert you cannot feel much heat. There will be a steel plate that will cover the gap between the surround and the top of the fireplace opening ... we had to have it custom fabricated and it is not finished yet.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
To answer your other question, the air coming from the vent of my insert is hot. When cranking it's uncomfortable to keep your hand there.

Please take some pictures. Maybe you and you husband remove the surround so we can see the liner and if there's anything there to stop hot air flowing up the chimney between the liner and the masonry. This is what begreen was asking when h mentioned block-off plate.
Here is a photo of the insert right after it was installed ...
 

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jatoxico

Minister of Fire
Aug 8, 2011
4,218
Long Island NY
Oh ... I forgot to mention that the entire chimney that is exposed + the part above the roof is limestone ... here is a photograph of it from shortly after we moved in. It is the chimney on the far right.
Nice looking place, a lot of character. A freestander would look nice in the fireplace too.

I have a somewhat similar install. Ground floor going up through 2 floors and the attic. Ceilings are regular height but I'm at about 24' from the top of the stove. Thinking maybe you're closer to 30' not 40'??

In any case it's unlikely that they insulated and installed a block off plate. Given the access you have you could easily do that now. This will not solve your current problem which sounds more like an operation issue at this point, but will vastly improve the performance in the long run. This only involves getting some Roxul from HD or Lowes to insulate above the stove and some light gauge metal to hold it in place. Search here at hearth for more info and how to.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
Nice looking place, a lot of character. A freestander would look nice in the fireplace too.

I have a somewhat similar install. Ground floor going up through 2 floors and the attic. Ceilings are regular height but I'm at about 24' from the top of the stove. Thinking maybe you're closer to 30' not 40'??

In any case it's unlikely that they insulated and installed a block off plate. Given the access you have you could easily do that now. This will not solve your current problem which sounds more like an operation issue at this point, but will vastly improve the performance in the long run. This only involves getting some Roxul from HD or Lowes to insulate above the stove and some light gauge metal to hold it in place. Search here at hearth for more info and how to.
Thank you! Will definitely add that to the Mr.'s to-do list, lol. I used smaller split wood as you suggested and the air being blown seems to be hotter. Though do you notice that the heat that radiates off the glass is hotter than the air blown? That is where I am now. ... oh no, it is definitely 40, Dealer had to confirm it with our Installer, and there was >1ft left after they installed it. The liner for the chimney that vents our boiler was almost 50ft ... our basement has 10ft ceilings. The way they built houses back in the 1800s is insane.
 

Slocketman

Member
Feb 10, 2016
31
Ohio, USA
. . .The fireplace that the insert was installed into is a corner fireplace with another fireplace in the next room in the same corner . . .
Besides the air coming out of the blower on the insert not being hot like it should be (which should be improved by the suggestions on how to decrease the air intake), the fact that there's another fireplace in the other room makes me think lots of cold outside air is likely being pulled into the house.

Unless the insert was installed with an Outside Air C(K)ombustion kit to ensure all air being fed to the fire is being pulled from outside the house directly into the insert, that fire (and strong draft up the 40' chimney) is going to be pulling cold air through any cracks in the walls and hampering the ability to heat the room.

Light a stick of incense and wander around the house while the fire's burning to locate any drafts (hold it close to the walls, the other fireplace, doors, windows, etc.) that could be sealed better. If the damper on that other chimney isn't fully sealing shut (& even if it is it may need blocked off better) I bet there's a huge draft coming in there.
 

Slocketman

Member
Feb 10, 2016
31
Ohio, USA
You may be able to turn down the air completely pretty quickly once the fire gets rolling. I am concerned about that 40ft stack. The potential for overfiring the stove is there due to too strong draft, especially once it gets colder.
Definitely this. The taller the chimney, and the larger the temperature differential between the outdoors and your house, the stronger the airflow (draft) will be through the insert. Turn the air way down over several minutes once the fire is burning well (watching that it doesn't go out entirely or start smoking lots) and it should allow the insert to absorb the heat instead of it all wooshing up the chimney. The wood will last much longer too.

. . .
The unit is also making a bit of noise ... not the blower but creaks and thuds (like with the break-in fires)
This is a good sign (within reason), the metal will make some creaks/thuds/pings as it absorbs heat and expands (& again when the fire dies and it cools down/contracts). Once all the metal of the insert is nice and hot the air coming out of the blower should be very warm.
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,852
South Puget Sound, WA
Not really sure we can remove the surround ... it seems well put in there. Our fireplace opening is taller than the insert so we could take a photo up the chimney to see what is there. I know that they insulated at the cap, but beyond that I am not sure. Honestly ... if you hold your hand above the insert you cannot feel much heat. There will be a steel plate that will cover the gap between the surround and the top of the fireplace opening ... we had to have it custom fabricated and it is not finished yet.
As the weather gets colder, draft is going to increase. That will change performance. You will probably see this with needing to close the air down quicker and the need to burn large splits to avoid them burning up too quickly. A 2" dial thermometer will help provide some estimation of how hot the insert is getting.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
Besides the air coming out of the blower on the insert not being hot like it should be (which should be improved by the suggestions on how to decrease the air intake), the fact that there's another fireplace in the other room makes me think lots of cold outside air is likely being pulled into the house.

Unless the insert was installed with an Outside Air C(K)ombustion kit to ensure all air being fed to the fire is being pulled from outside the house directly into the insert, that fire (and strong draft up the 40' chimney) is going to be pulling cold air through any cracks in the walls and hampering the ability to heat the room.

Light a stick of incense and wander around the house while the fire's burning to locate any drafts (hold it close to the walls, the other fireplace, doors, windows, etc.) that could be sealed better. If the damper on that other chimney isn't fully sealing shut (& even if it is it may need blocked off better) I bet there's a huge draft coming in there.
Nope ... I do not think that was installed, I will be sure to ask. We actually have 4 fireplaces on the first floor and 1 on the second floor. All of the dampers are closed but I do not know how tightly they seal since they are over 100 years old.
 

The DuRochers

New Member
Oct 25, 2016
16
Northwest Connecticut
As the weather gets colder, draft is going to increase. That will change performance. You will probably see this with needing to close the air down quicker and the need to burn large splits to avoid them burning up too quickly. A 2" dial thermometer will help provide some estimation of how hot the insert is getting.
Good to know. Should I adjust the fan speed too?! Think it is all the way up now ... should I lower it?
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,852
South Puget Sound, WA
That's your option. If you want hotter air, slow it down to low speed. When the stove is very hot run the blower at medium speed.
 
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