Used VC Encore...can not get extended burn time

[flyhop]

2006 VC Catalytic Encore...23' of 6" rigid steel chimney insert inside masonry chimney, top 18' terra cotta flue liner to cap. Used as supplemental heat in living room/dining room/kitchen area; makes wife happy.

Graduated from a VC Non-cat Aspen to used VC Cat Encore this season. Not ever had stove this size before. Doesn't seem to have been used much by previous owner (not much in way of burn marks inside or debris in channels). When PO moved it, they turned it upside down, and fireback wedge fell out (lost). New one on order. I pulled cat for inspection and almost no dust inside. Gaskets "seem" in good shape, although I'm not sure I'd know. Catalytic probe on wish list (have to pay off Christmas first). Doesn't smoke into house at all

Burned very nicely for 3 days. However, I have loaded it with 5-6 splits 30 minutes before going to bed the last 2 days, put the primary air damper on lowest setting possible (I can see the flap in back sitting in place) and kept the cat engaged. As this stove is new to us, I'm unwilling to pack it with wood until we've gotten to know it better. At 6am, no coals, barely any embers and little heat radiating from stove. Not what I envisioned for an 8-hour burn time. I'm wondering if I have an air leak that is allowing fire to run hotter than primary air setting.

Is there a means to test this stove for air leaks? Should I not leave for long period with cat engaged? Is this a common thing? Any advise on a diagnosis would be appreciated. Thanks in advance.

 

[flyhop]

Read all the posts from this thread...
https://www.hearth.com/talk/threads/2013-vc-burning-thread.118673/page-9

Realize my original question is much too broad, and I don't have all of the information to make informed decisions or ask the right questions. I'll be purchasing a griddle top and catalytic probe thermometer tonight.

I would like to know about the dollar bill test. Where on this stove is this "test" performed....and how is it done? Thanks.

 

[jharkin]

Dollar bill test is simple... Open door, place a dollar bill across the gasket and close the door on it. It should be difficult to pull the bill out. Do this all the way around EVERY gasket. If one is loose we can talk you through replacement.

When you did you night load, did you let it burn hot and get the load good and charred before closing damper and turning down? 500 griddle is the target once you have a thermo.

How is your wood? Is it dry, as in 1-2 years split and stacked?

 

[Snotrocket]

Have you ever been around the stove for a complete burn? Seems like a lot of unknowns on how it operates.

 

[flyhop]

Dollar bill test is simple... Open door, place a dollar bill across the gasket and close the door on it. It should be difficult to pull the bill out. Do this all the way around EVERY gasket. If one is loose we can talk you through replacement.

When you did you night load, did you let it burn hot and get the load good and charred before closing damper and turning down? 500 griddle is the target once you have a thermo.

How is your wood? Is it dry, as in 1-2 years split and stacked?

Wood is 2-3 years, split, stacked and covered. Mostly all oak and some pecan.

I gave it a good 1/2 hour to char and burn before I turned air down. Not sure about "closing damper" as this is our first catalytic stove, but I left the damper turned so that smoke went through the cat.

As to Snotrocket's comment/question, this is our second wood burning stove, but our first catalytic. Our first stove was very small. We've only just started using it and have had two full day-long burns with us in the house. Still learning the stove, so don't know that much. I'm asking questions about how it operates because we've never really seen one run well.

 

[jharkin]

The encore has two controls:

• The 'damper' also called a catalyst bypass is the handle on the left. This controls whether the smoke goes through the catalyst or straight up the chimney.
• The air control is the handle on the right.

If you left the damper closed through reloading and firing off a fresh load, you probably never got the cat hot enough to lightoff, which would explain short burn and poor heat. Further you stand a good chance of clogging it with ash that way, and will likely get smoke backing up into the room. The damper is always opened before you open the doors and when firing fresh wood.


Usual reload procedure:

1. Left handle back to open bypass
2. Right handle forward
3. Load wood
4. Let it burn wide open till wood is well charred and griddle temp is 500f
5. Left handle forward to close damper
6. Now start lowering the air control in stages to reach desired cruising temp. I do this over 5-15 min time.

My typical air settings when cruising are from full closed to 1/3 open depending on how much heat I need.

 

[jharkin]

A re post of a procedure I documented in my rebuild thread, try this out once you have griddle and cat probe thermometers:

• Start up a fire and let it burn wide open to warm up the stove
• On a new load you close the damper (bypass) when the griddle temp reads 500F (I go higher on big loads).
• If the cat lights off properly you should see probe temp rise to 1000F+ in 5 min or less, if it climbs slowly and stops around 800 that is a catalyst stall and you need to reopen the damper and heat it up some more then try again. Once the cat is active start closing down the air control in increments till you reach cruising. For me this is with the air between fully closed and 1/3 open, depending on how much heat you want.
• Any time you see the cat probe temp over 1600 you should be careful (1700+ is the danger zone) - either close the primary air completely to slow things down, or open up the primary air to get more fire in the box, which reduces the amount of smoke the cat has to burn, but burns the load up faster and throws a lot more heat.
  
• In cruising mode the probe temp will normally be in the 1100-1600 range (griddle might be 500-700 depending on how the primary air is set). During this part of the burn the air control will typically be almost closed but the stove is pumping out massive heat from the back casting due to the cat. Probe temp usually will slowly climb through the burn then peak and drop off fast. This part of the burn might be 1-2 hours for a couple splits or as much as 4-6 hours on a full packed load of Oak.
• Once the probe temp peaks and starts falling s you know the major out gassing phase of the burn is done. You still have hours of usable heat in the coals and at this point you can safely open up the air control to maintain griddle temp without fear of overheating the catalyst.
• Once the cat temp falls below 800 with the air control open the load is pretty much burned out and its time to reload.

 

[flyhop]

1. Left handle back to open bypass
2. Right handle forward
3. Load wood
4. Let it burn wide open till wood is well charred and griddle temp is 500f
5. Left handle forward to close damper
6. Now start lowering the air control in stages to reach desired cruising temp. I do this over 5-15 min time.

My typical air settings when cruising are from full closed to 1/3 open depending on how much heat I need.

This morning, ran the dollar bill test every 4-6 inches around all of the door mating places and the griddle. Lots of resistance in all but just a couple of spots, and even then could hear the paper running past the gaskets as I gave it some measure of force. I would say the gaskets are in reasonably good shape.

Next, I pulled off the plate covering the secondary air flap. The connection between the secondary air probe assembly coil and the linkage sat at about the 3 o'clock position. Loosened the nut and rotate the coil assembly until it sat at about the 6 o'clock position. I noted that the air flap has a little metal "ear" that prevents the flap from closing all of the way, and I left it alone. While there, I did brush out some dust/lint that was in the opening.

I also noted that the primary air flap seems to operate on a hinge and operates freely, but does not close all of the way. I am guess this cannot be adjusted. Does this suggest a lack of total control over the fire? There must be a reason. Perhaps a big fire would pull air DOWN the chimney? In any event, I see the gap in the primary air flap and its frame.

FWIW, I had read the manual about operating the damper when loading wood and firing new stuff before our first burn, and I am grateful for your "how-to-operate" writeup as a real world guide.

After all of this, I started the fire with paper, kindling, and only a couple 1 inch pieces of pecan. Ran this for about 15 minutes. Lotsa smoke coming out of the chimney. Seeing coals, I added 4 splits of oak and let it run. Damper was open to chimney (pushed back) and primary air control full forward (wide open) for the better part of an hour. Smoke heavy at first, but tapered off. When I started seeing coals (no thermometers yet...they are on order) and flames died back some, I closed the damper and bumped the air control back about 1/3. I could see some flames going into the hood, so I moved the air down to 1/2 position. Seems I remembered reading something about flames licking the combustor as being a bad thing. Fire still coming off splits, but no longer rolling into hood.

After about 5 minutes of this, I knocked air down to almost closed. Nice coals now, and nothing visible out of the chimney.

I hope to get cat monitor and griddle thermometer in next couple of days. Thanks for the help getting started.

 

[jharkin]

Next, I pulled off the plate covering the secondary air flap. The connection between the secondary air probe assembly coil and the linkage sat at about the 3 o'clock position. Loosened the nut and rotate the coil assembly until it sat at about the 6 o'clock position. I noted that the air flap has a little metal "ear" that prevents the flap from closing all of the way, and I left it alone. While there, I did brush out some dust/lint that was in the opening.

I would not set it to 6 o'clock. What will happen is the air will keep opening up at the cat gets hotter causing it to burn hotter. Most of us have better luck with it at 3oclock or even more open cold, then it closes as the cat heats up regulating cat temp.

I also noted that the primary air flap seems to operate on a hinge and operates freely, but does not close all of the way. I am guess this cannot be adjusted. Does this suggest a lack of total control over the fire? There must be a reason. Perhaps a big fire would pull air DOWN the chimney? In any event, I see the gap in the primary air flap and its frame.

Mine closes completely as best I can tell. Other say theirs does not. It is adjustable, get back behind the stove, close the lever all the way, now loosen the screw in the flap and pull the cable in and out till it just closes. Tighten the screw.

After all of this, I started the fire with paper, kindling, and only a couple 1 inch pieces of pecan. Ran this for about 15 minutes. Lotsa smoke coming out of the chimney. Seeing coals, I added 4 splits of oak and let it run. Damper was open to chimney (pushed back) and primary air control full forward (wide open) for the better part of an hour. Smoke heavy at first, but tapered off. When I started seeing coals (no thermometers yet...they are on order) and flames died back some, I closed the damper and bumped the air control back about 1/3. I could see some flames going into the hood, so I moved the air down to 1/2 position. Seems I remembered reading something about flames licking the combustor as being a bad thing. Fire still coming off splits, but no longer rolling into hood.

After about 5 minutes of this, I knocked air down to almost closed. Nice coals now, and nothing visible out of the chimney.

I hope to get cat monitor and griddle thermometer in next couple of days. Thanks for the help getting started.

Sounds like things are improving for you, great! Yea I see flames going into the hood on mine, no real way to prevent it I can see

 

[flyhop]

I would not set it to 6 o'clock. What will happen is the air will keep opening up at the cat gets hotter causing it to burn hotter. Most of us have better luck with it at 3oclock or even more open cold, then it closes as the cat heats up regulating cat temp.

Help me understand how this works please.

I'm working from the belief that as the cat temp increases, the coil will expand and the linkage will lower the secondary air flap, reducing the amount of air reaching the stove. Do I have that wrong?

Also, when the secondary flap is open, where is the air directed? Onto the fuel?

Thanks for your responses. Just trying to learn what I've got.