Vermont Castings burning too hot

[Jstarr]

Moved houses last year on the sidd of Guardian Mtn in Byrdcliffe, Woodstock NY. A beautiful secluded place in deep forest in a 1988 house. Unfortunately other than oil heat, the home had an originsl heatilator with the chimney double wall ss in a wooden chase that had been modified and was dangerous.
We got rid of the ineffective heatilator and relined the chimney properly and did a beautiful tile job over multiple layers of hardibacker. Bought a new Vermont Castings Encore with catlyst (our first, our old house had original Vigilant & Defiant) and connected it up, burning local red osk & cherry we seasoned a year under cover.
The stove burns very hot, always. Damper closed, air vent closed, it shoots uo to 750f in an hour and stays there till it runs out of fuel in about 5 hours.
Cracker Mill, who sold us this (and the previous 2 long ago) says stove is fine, offered to sell me a butterfly for the chimney.
Something seems wrong, leaky in the stove perhaps. Our old VC stoves gave us over 14 hours burn time.
Suggestions?

View attachment IMG_8386.jpeg

 

[Eman85]

Where are you measuring temps? Are you measuring catalyst temps? have you checked the gaskets? Been some posts about new VC stoves where gaskets fell off. My antique Encore goes 12 hrs with no problem when burning low.

 

[stoveliker]

How tall is the chimney from stove top to cap?
Do you have a flue temperature probe?

 

[EatenByLimestone]

That’s a really tall chimney. I wouldn’t be surprised if you need a key damper to keep draft under control.

Edit:
I could have sworn I saw the chimney was 33 feet. I must have imagined it.

How tall is the chimney?

 

[Jstarr]

Moved houses last year on the sidd of Guardian Mtn in Byrdcliffe, Woodstock NY. A beautiful secluded place in deep forest in a 1988 house. Unfortunately other than oil heat, the home had an originsl heatilator with the chimney double wall ss in a wooden chase that had been modified and was dangerous.
We got rid of the ineffective heatilator and relined the chimney properly and did a beautiful tile job over multiple layers of hardibacker. Bought a new Vermont Castings Encore with catlyst (our first, our old house had original Vigilant & Defiant) and connected it up, burning local red osk & cherry we seasoned a year under cover.
The stove burns very hot, always. Damper closed, air vent closed, it shoots uo to 750f in an hour and stays there till it runs out of fuel in about 5 hours.
Cracker Mill, who sold us this (and the previous 2 long ago) says stove is fine, offered to sell me a butterfly for the chimney.
Something seems wrong, leaky in the stove perhaps. Our old VC stoves gave us over 14 hours burn time.
Suggestions?

View attachment 324891

Right now the el cheapo griddle top round thermo says 650, the catalyst temp on the rear of the stove is pinned at top of scale, round magnetic one on the rear outlet pipe is at 450. Our stack is about 22' above stove rear entry. It wad around 3' lower and tended to be puffy and too close to roof.

View attachment IMG_8387.jpeg

 

[Jstarr]

Right now the el cheapo griddle top round thermo says 650, the catalyst temp on the rear of the stove is pinned at top of scale, round magnetic one on the rear outlet pipe is at 450. Our stack is about 22' above stove rear entry. It wad around 3' lower and tended to be puffy and too close to roof.

View attachment 324896

Sean from stove store (cracker mill on Rt 28) tells me my wood is too dry causing problem. Never heard that before. I do suspect a gasket or the bottom tray joint.

 

[Jstarr]

I spent some time recently doing visual inspection and with a candle and a stick of incense looking for obvious leaks. front door & griddle seem sound, bottom pan feels locked solid.
I don't know where else to check on this thing, there's a lot of heat shielding on the back & bottom that my elderly arms can't unscrew.

 

[Max W]

The damper the dealer offered should give you more control.
..

 

[Eman85]

Skip the smoke test do the dollar bill test. Accuracy of your thermometers should also be tested. Make sure the air control is closing, I use a mirror to see mine. Do you see the flames die down if you are burning with the air control open and then close it?

 

[stoveliker]

I agree with the above; it seems the chimney is not strangely out of spec (tho we didn't measure the draft...)

 

[Jstarr]

The damper the dealer offered should give you more control.
..

I would put one in as a last resort. I'm reluctant to adding anything to create a creosote trap or reduce the structural integrity of the pipe.

 

[Jstarr]

Skip the smoke test do the dollar bill test. Accuracy of your thermometers should also be tested. Make sure the air control is closing, I use a mirror to see mine. Do you see the flames die down if you are burning with the air control open and then close it?

I can do the bill test on the griddle & front door. Trying to figure out how to do it on the ash pan. I like the mirror for checking the air flap. The old ones were nicely visible. When I shut it, the stove still seems to not shut down fully, like it's still getting combistion air from somewhere. Thanks folks for good suggestions.

 

[stoveliker]

A damper should not be a creosote trap unless you close it too much. As long as you still have draft for the fire, and the temps in the flue are high enough, you're okay.

A (second) damper is not going to change the mechanical integrity of the pipe but will help decrease the heat going up the flue.

 

[Eman85]

I can do the bill test on the griddle & front door. Trying to figure out how to do it on the ash pan. I like the mirror for checking the air flap. The old ones were nicely visible. When I shut it, the stove still seems to not shut down fully, like it's still getting combistion air from somewhere. Thanks folks for good suggestions.

I can hear my air flap slam shut if I move my lever quickly. If I remember there were some where the cable was out of adjustment or binding. On the ash pan take a good look at the gasket and see if the crush is the same on all of it. Just a guess here but maybe chalk the contact area then check for witness marks after closing and opening.

 

[skb31]

Just a heads up, I never clean the ash pan that swings out. I’ll move a little ash out of the firebox but that’s it. The griddle gaskets are problematic. You can use a flashlight with the room darkened to see if light comes through from the inside.

As far as air flow. There’s a primary air control you’re familiar with but someone should get down behind the stove when it’s cooler and make sure it fully closes. I’ve not had an issue but some have said the cable hung up in the stove when new.

Just above that (if you have the 2040 cat version) is an uncontrolled secondary air flow. That feeds air into the stove as well and cannot be adjusted.

There is a learning curve with this stove and I’m still a noob so grain of salt and all that. I am having a damper installed at some point before next season. I’m not doing any large fuel loads since I don’t need it as a primary heat source. Smaller splits will spike the temps and can make the stove run very hot. This stove is unlike any I’ve used in 20+ years of wood burning.

 

[GrumpyDad]

Sean from stove store (cracker mill on Rt 28) tells me my wood is too dry causing problem. Never heard that before. I do suspect a gasket or the bottom tray joint.

Some stuck/crushed ash against the ash pan gasket can create enough of a gap to allow your fire to rage. It doesnt take much! Im sure you are checking how well the gaskets are sealing and have read the manual about how to adjust the doors to ensure you seal properly.

 

[JohnDaileyNH]

If it's an Encore 2040 Cat-C I'd check the griddle gaskets. I've seen a few people replace these right from the factory and fix the issue.