New setup

[DB Cooper71]

Hello from central Minnesota!

I just did a self install of a new Century CW2900. I'm going to use it to supplement my baseboard radiator gas furnace heat as much as possible. I'm new to burning/maintaining a wood burning appliance. I'd like any advice on my new unit and how to maximize its output to heat the main floor of my home. I know it would be difficult to get any heat to migrate to the basement. This may be long winded to provide as much info as possible. Here is my setup.

Home built in 1969. It's a ranch with a finished basement, 1600ish sq ft above ground and 1400ish below. The insert is in the fireplace on the main floor in a large 3 flue system, centrally located masonry chimney. The other 2 flues are to the basement open fireplace and the gas furnace. The main room is round with the living room, dining area, and kitchen, and the chimney right up through the middle and stairs down to the basement around the chimney. The ceiling is 12'. There is a large side room off one side. There are 3 bedrooms and 2 baths down a hallway the other direction. It's zoned with 2 thermostats upstairs and 2 downstairs. I think that covers the layout of the house in enough detail.

The fireplace insert
CW2900
16' of 5"x7" oval single wall SS flex liner in a 6"x8" terra cotta flue
No block off plate...yet
Included factory surround

So that's what I have. I've got an Auber Instruments digital probe thermometer in the liner 18" above the stove outlet. I chose a probe, even though it's a single wall, because I cannot see the liner to put an external thermometer on it, and I like precision anyway. There is a magnetic thermometer on the face of the stove, and I use an IR gun on it as well.

The liner is only insulated with rockwool insulation for the last 5', which is what is outside the house. The rest is uninsulated, but it's an interior chimney. I'm planning on taking the insert out this summer to install a block off plate. I didn't think it was necessary, but after reading threads here, I think it will make a difference in efficiency, help the stove heat faster, and keep more heat in the house.

My wood is a mix of ironwood, maple, ash, birch, elm, poplar, and cedar. I source it from a lady that lets me cut standing dead and fallen trees on her land. That's why it's such a mix. There is also some ash slabwood in there. It's all been seasoned for 2 years, as it was for the fireplace, but we didn't need use that very much due to it raising the heating bill.

My burning habits so far have been loading it full, cold start or small coals from overnight, top down start, and burning it down to coals before reloading, or adding 2-3 splits one time to keep it going, and letting it burn down to coals. Since it's not arctic conditions anymore, I use it in the mornings and evenings right now. When I start it, I leave the door cracked for 10-15 minutes to get things going. Then I run it wide open, until the stove temp is 300ish, or the flue gases are 950+. Then I start cutting the air back 1/4 at a time, until I get slow flames and good secondaries, until the air is a smidge from completely closed. This insert doesn't seem to like to have the air control completely closed, but very close to it works well.

Well, I think that is it. What does everyone think? Is my setup right? Am I operating the insert properly as far as temps and burning habits? Is there anything I'm doing improperly, or can do better? Thanks for reading my post and for any advice you may have.

Cheers!

 

[DB Cooper71]

Some things that I forgot,

I'm getting 4-6 hours burn time from startup to coals and ready for reload or burnout. It varies by the size of the splits and the species, but that's average. My glass stays clean, and the bricks are white once he fire is stable.

My running temps, once it's stable and the air control is mostly closed, are about 450 on the face of the insert and anywhere from 550-750 flue gases, depending on where it is in the burn cycle.

I think I'm doing things correctly by that info, but please advise me otherwise if it doesn't seem proper.

Thanks again!

 

[coreboy83]

I cant see the pics

 

[begreen]

It takes time for the mass of steel to warm up, even though the firebox is up to temp. Try starting to close the air when the flue temps reach ~600º F and stay under ~800F. Maybe close the air control 50% when flue temp is 500º and 75% when it reaches 600F. With a wide variety of wood species you will have to judge how fast to turn down the air and how much. Some wood will ignite quickly and other species like locust or ironwood may take twice as long.

Note that standing dead can sometimes still contain excess moisture. Try to get ahead by cutting now, splitting and stacking the wood under top cover to assure good burning. You'll want your firewood to be under 20% moisture content for best heat.

 

[DB Cooper71]

I cant see the pics

I didn't upload any yet. I'll get to that later today.

 

[DB Cooper71]

It takes time for the mass of steel to warm up, even though the firebox is up to temp. Try starting to close the air when the flue temps reach ~600º F and stay under ~800F. Maybe close the air control 50% when flue temp is 500º and 75% when it reaches 600F. With a wide variety of wood species you will have to judge how fast to turn down the air and how much. Some wood will ignite quickly and other species like locust or ironwood may take twice as long.

Note that standing dead can sometimes still contain excess moisture. Try to get ahead by cutting now, splitting and stacking the wood under top cover to assure good burning. You'll want your firewood to be under 20% moisture content for best heat.

Thanks for the reply. I actually tend to watch the fire more than the temps when making air adjustments. Those temps are just the average and seemed the best to relate what I've been doing. I will try to start closing the air control sooner, by your advice, and see how it goes. Maybe this will extend my burn times, by not burning the wood too quickly at the beginning? Maybe the stove will come up to temp quicker by not letting the heat escape as much? Hopefully both happen!

I will start cutting soon. I'm waiting for more of the snow to melt over the next week or so. I still had 3' in my backyard 2 weeks ago! I may also buy a cord or 2 of well seasoned hardwood to help get next season started, and allow what I cut this spring to dry more. I've got 2-3 cords of wood that's been split, stacked, and drying for 2 years right now.

Like I said, I'm new to this. So I will take any advice given and put it to the test, since I don't think I've developed any bad habits yet. I'd like to be dialed in by next winter.

 

[begreen]

Closing the air sooner will extend the burn time and also this will be gentler on the liner. Don't squelch the flame, but cut back the air so that the flames start getting lazy as soon as is possible with the wood that is being burned. I am typically starting to turn down the air in our stove around 400-500º flue temp. Stove top might only be 250º at that point if it's a cold start.

 

[DB Cooper71]

I cant see the pics

Here's a pic of the insert.

 

[joneo]

My burning habits so far have been loading it full, cold start or small coals from overnight, top down start, and burning it down to coals before reloading, or adding 2-3 splits one time to keep it going, and letting it burn down to coals. Since it's not arctic conditions anymore, I use it in the mornings and evenings right now. When I start it, I leave the door cracked for 10-15 minutes to get things going. Then I run it wide open, until the stove temp is 300ish, or the flue gases are 950+.

Cheers!

Congratulations on your new stove! I'm a new owner too, and according to the directions that came with my Regency i2400 insert, it specifically stated to not build a roaring fire in a cold stove. So I have been slowly heating mine up with a small fire before loading it up.

Also, what are temperature differences between the magnetic thermometer vs the probe vs the IR gun? I only have a magnetic one on the face, and am assuming it reads lower than the actual temp.

 

[bholler]

Hello from central Minnesota!

I just did a self install of a new Century CW2900. I'm going to use it to supplement my baseboard radiator gas furnace heat as much as possible. I'm new to burning/maintaining a wood burning appliance. I'd like any advice on my new unit and how to maximize its output to heat the main floor of my home. I know it would be difficult to get any heat to migrate to the basement. This may be long winded to provide as much info as possible. Here is my setup.

Home built in 1969. It's a ranch with a finished basement, 1600ish sq ft above ground and 1400ish below. The insert is in the fireplace on the main floor in a large 3 flue system, centrally located masonry chimney. The other 2 flues are to the basement open fireplace and the gas furnace. The main room is round with the living room, dining area, and kitchen, and the chimney right up through the middle and stairs down to the basement around the chimney. The ceiling is 12'. There is a large side room off one side. There are 3 bedrooms and 2 baths down a hallway the other direction. It's zoned with 2 thermostats upstairs and 2 downstairs. I think that covers the layout of the house in enough detail.

The fireplace insert
CW2900
16' of 5"x7" oval single wall SS flex liner in a 6"x8" terra cotta flue
No block off plate...yet
Included factory surround

So that's what I have. I've got an Auber Instruments digital probe thermometer in the liner 18" above the stove outlet. I chose a probe, even though it's a single wall, because I cannot see the liner to put an external thermometer on it, and I like precision anyway. There is a magnetic thermometer on the face of the stove, and I use an IR gun on it as well.

The liner is only insulated with rockwool insulation for the last 5', which is what is outside the house. The rest is uninsulated, but it's an interior chimney. I'm planning on taking the insert out this summer to install a block off plate. I didn't think it was necessary, but after reading threads here, I think it will make a difference in efficiency, help the stove heat faster, and keep more heat in the house.

My wood is a mix of ironwood, maple, ash, birch, elm, poplar, and cedar. I source it from a lady that lets me cut standing dead and fallen trees on her land. That's why it's such a mix. There is also some ash slabwood in there. It's all been seasoned for 2 years, as it was for the fireplace, but we didn't need use that very much due to it raising the heating bill.

My burning habits so far have been loading it full, cold start or small coals from overnight, top down start, and burning it down to coals before reloading, or adding 2-3 splits one time to keep it going, and letting it burn down to coals. Since it's not arctic conditions anymore, I use it in the mornings and evenings right now. When I start it, I leave the door cracked for 10-15 minutes to get things going. Then I run it wide open, until the stove temp is 300ish, or the flue gases are 950+. Then I start cutting the air back 1/4 at a time, until I get slow flames and good secondaries, until the air is a smidge from completely closed. This insert doesn't seem to like to have the air control completely closed, but very close to it works well.

Well, I think that is it. What does everyone think? Is my setup right? Am I operating the insert properly as far as temps and burning habits? Is there anything I'm doing improperly, or can do better? Thanks for reading my post and for any advice you may have.

Cheers!

Why did you only insulate the last 5 feet? Did you confirm that you have the required clearances for the internal part of the chimney?

 

[DB Cooper71]

Why did you only insulate the last 5 feet? Did you confirm that you have the required clearances for the internal part of the chimney?

I insulated the last 5' because that is what is outside the house and did that on the recommendation of my chimney sweep, a local dealer/installer, and the seller of the liner (who is also a professional dealer/installer/sweep).

I didn't insulate the rest for a couple of reasons. First, it is an interior chimney and had a good draft with the open fireplace, and has one now too. Second, the terra cotta flue lining and mortar joints are in excellent shape. My chimney sweep dropped a camera when he cleaned it before the install to confirm the condition for me. Lastly, the flue is only 6"x8" inside dimensions with an offset halfway down. I would have to have downsized the liner and possibly constricted the draft in order to insulate it without ripping all of the insulation off of it while shoving it down and through the offset in the flue.

I asked all of the people mentioned above about insulating the whole thing, and they said it didn't necessarily need it in my situation. If it is not to code in this configuration, then my recourse is to use the pourable vermiculite/perlite/Portland insulation. The problem I see with that is that once the liner is in place, there will be places it touches the terra cotta at the offset, and those will not get insulated by pouring anything around it.

I would like to hear your opinion and any codes that I might be violating. My local laws just state it needs a Class A liner. If I'm wrong or have a dangerous setup, then please let me know. I appreciate your input. Thanks

 

[DB Cooper71]

Congratulations on your new stove! I'm a new owner too, and according to the directions that came with my Regency i2400 insert, it specifically stated to not build a roaring fire in a cold stove. So I have been slowly heating mine up with a small fire before loading it up.

Also, what are temperature differences between the magnetic thermometer vs the probe vs the IR gun? I only have a magnetic one on the face, and am assuming it reads lower than the actual temp.

I broke in the insert outside with 4 fires, from a short kindling fire, progressing to a good ripper with the last one. After that, the manual says it's ready for regular use. It heats up at a nice steady pace with a top-down start, so it's not going from zero to blazing all that quickly. I assume that "regular use" means load it up and light it.

As far as temps go, the probe is reading the flue gases. That should always be higher than stove, unless the stove is blistering hot when the coals finally flame out, but I doubt it will ever be lower than the other 2.

The IR gun reads about 30-50 degrees hotter or cooler than the magnetic most times, because it's reading in real time. It also reads differently depending on the area of the insert and where the fire is concentrated at that time. The magnetic takes longer to heat up or cool down and stays in one place. I have it there as a quick visual reference that the stove is within an acceptable operating range. Plus, the cat loves chasing red lasers, and I limit its use so he doesn't learn that lesson the hard way!

 

[bholler]

I insulated the last 5' because that is what is outside the house and did that on the recommendation of my chimney sweep, a local dealer/installer, and the seller of the liner (who is also a professional dealer/installer/sweep).

I didn't insulate the rest for a couple of reasons. First, it is an interior chimney and had a good draft with the open fireplace, and has one now too. Second, the terra cotta flue lining and mortar joints are in excellent shape. My chimney sweep dropped a camera when he cleaned it before the install to confirm the condition for me. Lastly, the flue is only 6"x8" inside dimensions with an offset halfway down. I would have to have downsized the liner and possibly constricted the draft in order to insulate it without ripping all of the insulation off of it while shoving it down and through the offset in the flue.

I asked all of the people mentioned above about insulating the whole thing, and they said it didn't necessarily need it in my situation. If it is not to code in this configuration, then my recourse is to use the pourable vermiculite/perlite/Portland insulation. The problem I see with that is that once the liner is in place, there will be places it touches the terra cotta at the offset, and those will not get insulated by pouring anything around it.

I would like to hear your opinion and any codes that I might be violating. My local laws just state it needs a Class A liner. If I'm wrong or have a dangerous setup, then please let me know. I appreciate your input. Thanks

In order for an internal masonry chimney to be up to code you need 2" of clearance to combustibles from the outside of the masonry structure of the chimney. If you don't have this which very few chimneys do you need to insulate the liner in order to stop the transfer of heat through that masonry especially in the case of a chimney fire it is possible for enough heat to transfer through to start a structure fire. And the existence and condition of clay liners has no bearing whatsoever on this requirement.

This is covered under R1003.18 of irc which Minnesota follows

 

[DB Cooper71]

In order for an internal masonry chimney to be up to code you need 2" of clearance to combustibles from the outside of the masonry structure of the chimney. If you don't have this which very few chimneys do you need to insulate the liner in order to stop the transfer of heat through that masonry especially in the case of a chimney fire it is possible for enough heat to transfer through to start a structure fire. And the existence and condition of clay liners has no bearing whatsoever on this requirement.

This is covered under R1003.18 of irc which Minnesota follows

Gotcha, thanks

 

[DB Cooper71]

In order for an internal masonry chimney to be up to code you need 2" of clearance to combustibles from the outside of the masonry structure of the chimney. If you don't have this which very few chimneys do you need to insulate the liner in order to stop the transfer of heat through that masonry especially in the case of a chimney fire it is possible for enough heat to transfer through to start a structure fire. And the existence and condition of clay liners has no bearing whatsoever on this requirement.

This is covered under R1003.18 of irc which Minnesota follows

I just researched your reply, and you are absolutely correct. Thanks a lot for telling me. I know there are plenty of uninsulated liners in use out there, but that doesn't make it right or safe for me to do so.

I don't have those clearances to the ceiling beams, and I doubt I have it with the roof beams or sheeting, either. Why would anyone without a horse in the race tell me it was OK? I can understand the liner seller just trying to make a sale, but my chimney sweep and both local installers (both very well respected I might add) are wrong...

That's not as important as the fact that I have to remediate. I don't think I have the clearance to insulate with a foil-backed blanket. I think it will get ripped right off during a reinstallation attempt, especially at the offset. I'm going to have to fashion a catch plate and pour the insulation. I want a block off plate in there anyway. This will cover both situations.

Thanks again for taking the time to educate me. It hasn't fallen on deaf ears. I'm going to try to get it done ASAP.

 

[bholler]

I just researched your reply, and you are absolutely correct. Thanks a lot for telling me. I know there are plenty of uninsulated liners in use out there, but that doesn't make it right or safe for me to do so.

I don't have those clearances to the ceiling beams, and I doubt I have it with the roof beams or sheeting, either. Why would anyone without a horse in the race tell me it was OK? I can understand the liner seller just trying to make a sale, but my chimney sweep and both local installers (both very well respected I might add) are wrong...

That's not as important as the fact that I have to remediate. I don't think I have the clearance to insulate with a foil-backed blanket. I think it will get ripped right off during a reinstallation attempt, especially at the offset. I'm going to have to fashion a catch plate and pour the insulation. I want a block off plate in there anyway. This will cover both situations.

Thanks again for taking the time to educate me. It hasn't fallen on deaf ears. I'm going to try to get it done ASAP.

Pour in is certainly better than nothing but you actually need more room to get zero clearance with pour in. You need a full 1" of insulation on all sides with that type while only .5" with wrap. But yes it is hard to fitva wrapped liner in a 7x11 clay liner especially with an offset.