VC Aspen C3 (2023) Can’t Heat Small Room

[meagloth]

I have a VC Aspen C3 that I bought new in 2023. We installed it in February of 2024 and so didn’t use it much that year. It’s set back into an old brick fireplace as you can see in the picture.
Last winter we used it a good bit and found it struggles to put out any heat at all. Our house is VERY small and it could barely warm up the 12x12 living room. We put it up to our wood not being well seasoned. I build a lean to for the wood and it’s been sitting dry and covered for another year. It’s white oak, soft maple and sweetgum.
Well this year it’s been just as bad. It doesn’t seem to matter how small I split it or how well I stack it. As soon as I close the door the fire simmers down and the stove makes charcoal in the back and only has a lazy flame at the front, or just red coals. I can not boil a pot of water on the cook top. It will simmer but never breach a rolling boil. It does not come close to heating our 700sqft house. I believe the automatic air control is to blame. The chimney and cold air intake are clear. The wood is dry.

Is there anything I can do to fix this? Some adjustment for the air thermostat? I am not sure if the thermostat is supposed to go by room temp or combustion temp, maybe being in the brick alcove is making it sense warmer than it should?
I can not find any good repair of disassembly info online (the exploded view in the manual is only somewhat helpful) and the dealer I bought it from said they “don’t really do repair stuff”
I would rather have a manual damper than this BS, but I can’t find anyone has done that before.

 

[Todd]

How tall is your chimney? Is it lined?

 

[stovelark]

Something is not right- in your area, that stove should really keep you warm. Are you losing it up the chimney? You do have a 6 inch liner the whole way? Do you have a stove top thermometer? Not even boiling water sounds very suspicious, wet wood? Have you tried some store bundled wood to see if that burns different? And are you fully loading? Good luck...

 

[stoveliker]

Also, do you have a block-off plate where the pipe goes into the brick chimney?

 

[meagloth]

The chimney is a straight run, about 20 or 25’ through the roof. It is 6” double walled metal inside the chimney but the old chimney only goes to the attic. In the attic it’s triple wall insulated. The block off plate is where the chimney is ‘cut’ in the attic if that makes sense. I have also installed and electric fan that blows air backwards through the chimney and out into the room. It helps a little but the stove just doesn’t get that hot.

 

[begreen]

As a process of elimination, the wood moisture content should be checked.

When was the flue last cleaned? Is there a screen at the chimney cap? If so, check that for plugging.

 

[stoveliker]

The chimney is a straight run, about 20 or 25’ through the roof. It is 6” double walled metal inside the chimney but the old chimney only goes to the attic. In the attic it’s triple wall insulated. The block off plate is where the chimney is ‘cut’ in the attic if that makes sense. I have also installed and electric fan that blows air backwards through the chimney and out into the room. It helps a little but the stove just doesn’t get that hot.

even with an inside chimney, a lot of heat might go up from the alcove until it hits the plate at the attic.
Best is to seal the whole thing right where the pipe enters the brick chimney directly above the stove.

(And yes all of the others above can be an issue too. Including wet wood and a 25' chimney sucking way too much heat up the flue rather than allowing it to radiate out into the room.)

 

[meagloth]

Here is a video of how I operate the stove.

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Cooktop surface measured up to 600F after 2 hours but the kettle just sits there and “tsshhhhhh” never boils proper.

The wood mostly measured 2-5 Mohms which for hardwood I believe is mid teens moisture percent. The big sweetgum split I loaded measured OL, it was very dry.

Chimney cap is not plugged and chimney is nowhere near clogged, I checked yesterday.

 

[Todd]

Something is up with your draft. Sparks and smoke shouldn’t be coming out during reloads like that. Are your liner connections ok?

 

[stoveliker]

Also, (I didn't have the sound on), did you resplit the wood right before you measured it? (And it's room temp, right?)

 

[stovelark]

The stovetop temp, if I remember correctly, the cooktop portion will read much higher than the cast top of the stove... the fire still seemed kinda sluggish too, I'm curious when you first start the stove, does the flame change in its movement as the stove heats up? This stove has a thermostatic draft system I believe? You don't manually control the primary air? I'm wondering if therein lies the issue... or may be part of the issue. Good luck with her.

 

[begreen]

The load looks a bit small and loose instead of packed on a coal bed. If the wood is not fully seasoned, heat output will be reduced.

 

[meagloth]

Something is up with your draft. Sparks and smoke shouldn’t be coming out during reloads like that. Are your liner connections ok?

What would be the best way to go about verifying this? I have never seen smoke leak from the chimney or into the attic.
Is there any value in measure exhaust temp at the top of the flue?

 

[begreen]

The C3 is thermostatically operated. The thermostat is at the back of the stove. Normally this would be out in the room. I wonder if the thermostat is getting a false reading due to the rear of the stove being deep into the small fireplace cavity? It may have some influence, though 600º on the cookplate is not bad.

 

[stoveliker]

Yes, that is a good possibility.
The manual says it needs 8" from the rear wall to the rear of the stove. Not sure how that would change if the space is low (i.e. heats even up faster).

On the other hand, it appears from the answers above that no block off plate is there, meaning a lot of heat can go up the chimney outside of the flue. That scenario would be consistent with a "normal" stove top temperature.

 

[meagloth]

The C3 is thermostatically operated. The thermostat is at the back of the stove. Normally this would be out in the room. I wonder if the thermostat is getting a false reading due to the rear of the stove being deep into the small fireplace cavity? It may have some influence, though 600º on the cookplate is not bad.

I wonder this also and am curious if anyone has any info on how the thermostat actually works, where it takes temperature from, if it can be overridden or adjusted.
I was surprised how high the cook top temperature was last night but I am skeptical that much heat is really going up into the attic. My house is really small.
It is not cold in my area. Last night the room started at 68 degrees on the thermometer 3ft from the stove, and after burning in the video for two hours the room had warmed to… 68 dgrees. 0 degrees!

I know my setup isn’t optimal but our primary concern when we bought was that it would be too hot. I’m really surprised and frustrated to have the opposite problem. Thinking of the big ice storm they are forecasting for this weekend.

 

[begreen]

The heat is going somewhere. Either the house is seriously uninsulated and leaky or a ton is heading up the chimney. Two hours of a stove at 600º is like 50,000 BTUs. Is there a ceiling grille for an attic fan in the house?

 

[stoveliker]

I wonder this also and am curious if anyone has any info on how the thermostat actually works, where it takes temperature from, if it can be overridden or adjusted.
I was surprised how high the cook top temperature was last night but I am skeptical that much heat is really going up into the attic. My house is really small.
It is not cold in my area. Last night the room started at 68 degrees on the thermometer 3ft from the stove, and after burning in the video for two hours the room had warmed to… 68 dgrees. 0 degrees!

I know my setup isn’t optimal but our primary concern when we bought was that it would be too hot. I’m really surprised and frustrated to have the opposite problem. Thinking of the big ice storm they are forecasting for this weekend.

The thermostat most likely is a bimetal coil that closes the (primary) air gradually when it gets hotter.

One thing that would be good is to have a flue probe. Or even a magnetic thermometer on the flue.

 

[meagloth]

contemplating on in tonight and

The heat is going somewhere. Either the house is seriously uninsulated and leaky or a ton is heading up the chimney. Two hours of a stove at 600º is like 50,000 BTUs. Is there a ceiling grille for an attic fan in the house?

house is 100 years old no insulation in the walls and big time drafty. But also if it’s not too cold out the 1 ton heat pump is able to keep it stable. Under 30 the heat pump loses efficiency and struggles. But 50000 btus is 4x what my heat pump puts out. If most of that heat is going to the attic I would expect my attic to be pretty toasty, but I have been up there and checked while it’s running, it’s still chilly.

I was looking at it and pondering today and I think I before I tear it up I am going to put a block off above the stove and make some kind of temporary baffle to blow cool air behind the stove with a box fan. We’ll see if that makes a difference.

 

[Todd]

If there’s no block off plate maybe temporarily stuff some rock wool insulation up there to see if it makes a difference.

A small fan on the floor in front of the stove blowing into the fireplace may help push the heat out.

 

[meagloth]

If there’s no block off plate maybe temporarily stuff some rock wool insulation up there to see if it makes a difference.

A small fan on the floor in front of the stove blowing into the fireplace may help push the heat out.

I will make block off plate and put rockwool behind it tonight. I have tried extensive fan configurations and none have made a big difference. There’s a box fan blowing over it right now. One I thought was sure to be successful was a fan in a secondary flue in the back of the chimney blowing air down and around the stove, countercurrent to the rising heat. You could feel the warm air gently coming out of the stove. I think it helped a little but not so much it was worth the noise of the 6” exhaust fan droning

 

[bigealta]

You want a small fan, on low, on the floor pointed under and up a bit from a corner.
You are trying to get the coldest floor air and gently push it around and up a bit to just help increase the rising heat from the stove.
If the fan is to high and you overly mix the cold air with the warm air that can sometimes not help as much unless the area around the stove is very hot. (which in your case it could be).

I also second the "Check your draft" possibly for a blockage, as there is No Way sparks should be flying out the front like that.

 

[bigealta]

With 600F stovetop you should be getting cooked out of your house.

If it was me i'd rear vent that to get it out further.

 

[meagloth]

Is there any way to check the draft other than looking down the chimney? I have done this and it is a clear run all the way down. A little creosote but certainly no blockage. I can see down to the manual flue valve we installed (thinking at the time that we would have to throttle it down).

It would be hard to take the pipe off the stove and pull it out. I think I would have to take down the entire chimney, or maybe take the legs off the stove and lower it

 

[begreen]

One thing that will kill draft is air leaking into the flue system. Make sure the liner has no flaws and is properly attached to the stove's flue collar with an appliance adapter. The transition is another place to check on.