VC Defiant not putting out as much as I thought it should.

[aaajaws]

I have a 2016 Vermont Castings Defiant 2n1. Up here just south of the Canadian border it can get mighty cold and the home is only 2x4 construction ( I know why would anyone cheap out and not go 2x6 that far north , I bought it not built it. anyway sorry I degress.

I was limited by the fireplace opening as to what I could install needed horizontal exhaust.

The questions why does it seem like the stove decreasses in temp once the Cat is enguage ... is it simply because of the slower burn / choking ? I had a Buck 91 in my CT house loved that monster . Temps would rise considerably once the CAT was engaged.

Yes Wood seasoned 2 years although no Red Oak like CT its made up of maple, white birch and others.

It is my primary heat source for 2200 sqft 4 br. I installed the blower kit which did help out some but I think there is more to go.

Also the difference between flue temps / vrs top of stove temps big difference. Which one to ebgauge the CAT ?

I guess I looking for someone who has his VC Defiant dialed in and would like to share some tips he found out over time

Thanks
Jaws

 

[RandyBoBandy]

Head over to the VC owners thread and fill us in on your start up procedure, moisture content of wood, stove setup, chimney height. Do you have a stove top thermo, pipe thermo, cat probe thermo?

 

[RandyBoBandy]

For a quick reference I engage my cat at 600 degrees on the stove pipe. This is using a probe thermo on double wall pipe. I then leave my air wide open until the whole load is charred and the the stove top temp is north of 400 headed to 500. I generally try and cruise the stove between 500-600 degrees stove top. Another element to running this stove is keeping an eye on your cat temps. During the above procedure, if the cat is screaming past 1400 degrees I start to turn my air down earlier to keep it from going past 1500-1550 degrees. If you scroll through past years of the VC owners threads you will get lots of info on operating this stove successfully. And ask any questions you may have. Others will chime in eventually.

 

[aaajaws]

For a quick reference I engage my cat at 600 degrees on the stove pipe. This is using a probe thermo on double wall pipe. I then leave my air wide open until the whole load is charred and the the stove top temp is north of 400 headed to 500. I generally try and cruise the stove between 500-600 degrees stove top. Another element to running this stove is keeping an eye on your cat temps. During the above procedure, if the cat is screaming past 1400 degrees I start to turn my air down earlier to keep it from going past 1500-1550 degrees. If you scroll through past years of the VC owners threads you will get lots of info on operating this stove successfully. And ask any questions you may have. Others will chime in eventually.

How or with what are you checking the CAT temps ?

 

[stoveliker]

Is the opening to your (original) chimney properly closed, sealed, and insulated?

 

[aaajaws]

Is the opening to your (original) chimney properly closed, sealed, and insulated?

I have heading straight out of the back horizontally the pipe into a T. From the straight up into a 6" Stainless Steel flex pipe about 5 ' Problem is Chimney is 5 7/8" so had to stop there and then just the flue. But around the 6" SS pipe at the damper opening I have it packed with a white insulation designed for boilers not to burn to prevent any air / heat loss. well hopefully most of it.

 

[stoveliker]

How tall is your chimney? What does the manual recommend regarding length and (insulated?) liner.

 

[ajayabb]

How or with what are you checking the CAT temps ?

Most of us VC owners have Cat probes installed in the back of the stove. There is a small hole created for this purpose It may have a plastic cover over it

 

[defiant3]

Frankly, 2200 sq ft in that climate with maybe not the best insulation is a heavy lift for that stove. It is NOT the same as the original Defiant.

 

[aaajaws]

Frankly, 2200 sq ft in that climate with maybe not the best insulation is a heavy lift for that stove. It is NOT the same as the original Defiant.

My thoughts were the same. Just wanted to make sure I was maximizing the stove to it fullest potential. I did add a fan kit and push some air with a box fan too which helps a lot .

 

[Woodsplitter67]

when your saying your stove is cooling down with the cat on.. what is the actual temperature of the stove...

 

[aaajaws]

The thermometer on top and on exhaust outlet will go from 500° down to the 300° in a fairly short time

 

[Woodsplitter67]

sounds like your closing the damper and turning the air all the way back and the stove temp is droppingto 300... is this correct

 

[RandyBoBandy]

How or with what are you checking the CAT temps ?

I use a digital probe thermometer to manage cat temps. Auber Instruments AT100 with a K-type probe.

 

[RandyBoBandy]

The thermometer on top and on exhaust outlet will go from 500° down to the 300° in a fairly short time

Your flue temps will always drop when engaging the cat. For the most part my flue temps cruise right around 400 degrees when the damper is closed.

 

[gthomas785]

That is what happens to me if I load it too full after a cold start. And yeah it's normal for the flue tem to drop a bit after engaging the cat, since the cat needs to heat up. Is that what's happening? Does it also happen when reloading?

Try just a few splits for the initial load, when they're burning good close the damper but leave the air open for a while (like 20 mins) to get the cat heated up. Let the splits burn down to coals, then adding a full load on the hot coals should work much better.


Also, have you checked the combustor to make sure it is not clogged?

 

[RandyBoBandy]

This is a 2n1 stove but what’s is the actual model number?

 

[aaajaws]

Frankly, 2200 sq ft in that climate with maybe not the best insulation is a heavy lift for that stove. It is NOT the same as the original Defiant.

I have a room at the back of the house over the garage that I keep closed off so working on 1850 sqft

 

[aaajaws]

Yes I fell off the face of the earth sorry long story Life happens

CAT is clean, inspect fairly often, clean out alot of the ash fairly often too.

Start up procedure from Cold . Front glass doors closed , I use some news paper crumbled up some kiln dried pine from the Basement wood shop scrap pile and a couple 3 sticks of birch, maple , maybe a piece of white cedar all well aged over a year . Damper on Left , air on right wide open . Still a PIA to get going ( Chimney is 25' Masonry, has 5 ' of stainless coming out the back up into Fireplace damper area , surrounded by white boiler insulation. (Yes Chimney is cleaned beginning of every season) .

Once a small flame ( draft started ) I crack open either the front glass unless smoke then crack open the ASH tray until good draft and burning well then I close it . Will load wood as needed takes about 1/2 hr can get up to 400 -500 on griddle top so I engage the CAT left handle - Damper. I rarely if every close off the air Right handle ( I tried that lowering right handle air supply but after awhile I got puff back. Soon as I engage the CAT temps seem to quickly drop and have to release the cat again for awhile . It just never Seems to take off like my Buck 91 did .

Warm Restart ....most of the time throw some seasoned splits in open Ash drawer , inferno peruses close it off after a good burn wait til 450-500 then engage the CAT same thing happens

Anyway seems like I run more time without CAT then with :0( .
Any input would be much appreciated , Knowledge is power always like to learn something new everyday .
Thanks
Ken

PS where is the "VC Owners forum" someone mentioned ???

 

[Woodsplitter67]

This is sounding more like a draft issue to me. Back puffing happens when the draft is weak and the combustibles light off in the box suddenly, having to open the ash drawer is another sign of air restriction, on a cold start i start my fire with my small wood on the bottom and the paper.. 2 sheets on top. I light it up with the door cracked open and my stove is taking off,. .. or wet wood, do you have a moisture meter and have you checked the moisture on a open face of a freshly split piece of wood.
How are you measuring stove top temp and cat temp

 

[peakbagger]

VC's original owners developed some great trademark names with the original designs. The name Defiant was a 24 karat gold trademark and even the big recall to upgrade the firebacks didnt seem to impact the value of the name. 20 years after the originals came out, used units would sell for what new competitors would sell for. The fundamental problem was the original Defiant was designed to be too large for a typical modern house as the person who designed it designed it to heat a very poorly insulated equivalent of a barn (actually a cluster housing concept). As VC passed through subsequent owners the trademarks went with the deal and it made sense to keep the Defiant name and visual look while making a modern stove that could meet emissions. The problem is a modern stove is going to have far narrower operating range than an unregulated stove and the way to deal with that was to downsize the output of later models with a Defiant nameplate to better fit modern homes. Swap in an original Defiant into your house and it will drive you out but the tradeoff is they really were temperamental to try to turn down and less efficient when running at less than 100% output.

With respect to your building construction, remember Live Free or Die is the states motto. NH has lagged with model energy code legislation and most small towns near the Canadian border rarely have building inspectors for residential and the ones that do, do not enforce the energy codes in place. Thus many homes in the region were constructed by contractors that knew what they could get away with. They knew that buyers want looks and features and that was what sells but they also knew that typical buyer was clueless about energy efficiency, so they cut lots of corners and subsequent owners pay the price. The typical home inspection skips right over energy efficiency. There are some great contractors in the area that can build a energy efficient house but they are the minority and usually booked out for a couple of seasons. Even then, if they are not supervised by someone who knows the energy efficient construction corners will be cut.

If you are a Eversource customer, if you havent taken advantage of their Home Performance program, you should consider it. (broken link removed to https://www.eversource.com/content/nh/residential/save-money-energy/energy-efficiency-programs/home-performance-with-energy-star/homeowners) You pay them $100 and they do a fairly good energy audit including blower door testing. The recommend upgrades (mostly infiltration reduction) and rank them for payback. Many of the low hanging fruit are less than one year payback. You authorize the work and Eversource pays 50% of the cost. They then do post work blower door testing to prove that the upgrades work. They even rebate the $100 fee if you have a minimal amount of work done.

Remember the most efficient way to burn wood is not to burn it as you have reduced the heat demand.

 

[aaajaws]

VC's original owners developed some great trademark names with the original designs. The name Defiant was a 24 karat gold trademark and even the big recall to upgrade the firebacks didnt seem to impact the value of the name. 20 years after the originals came out, used units would sell for what new competitors would sell for. The fundamental problem was the original Defiant was designed to be too large for a typical modern house as the person who designed it designed it to heat a very poorly insulated equivalent of a barn (actually a cluster housing concept). As VC passed through subsequent owners the trademarks went with the deal and it made sense to keep the Defiant name and visual look while making a modern stove that could meet emissions. The problem is a modern stove is going to have far narrower operating range than an unregulated stove and the way to deal with that was to downsize the output of later models with a Defiant nameplate to better fit modern homes. Swap in an original Defiant into your house and it will drive you out but the tradeoff is they really were temperamental to try to turn down and less efficient when running at less than 100% output.

With respect to your building construction, remember Live Free or Die is the states motto. NH has lagged with model energy code legislation and most small towns near the Canadian border rarely have building inspectors for residential and the ones that do, do not enforce the energy codes in place. Thus many homes in the region were constructed by contractors that knew what they could get away with. They knew that buyers want looks and features and that was what sells but they also knew that typical buyer was clueless about energy efficiency, so they cut lots of corners and subsequent owners pay the price. The typical home inspection skips right over energy efficiency. There are some great contractors in the area that can build a energy efficient house but they are the minority and usually booked out for a couple of seasons. Even then, if they are not supervised by someone who knows the energy efficient construction corners will be cut.

If you are a Eversource customer, if you havent taken advantage of their Home Performance program, you should consider it. (broken link removed to https://www.eversource.com/content/nh/residential/save-money-energy/energy-efficiency-programs/home-performance-with-energy-star/homeowners) You pay them $100 and they do a fairly good energy audit including blower door testing. The recommend upgrades (mostly infiltration reduction) and rank them for payback. Many of the low hanging fruit are less than one year payback. You authorize the work and Eversource pays 50% of the cost. They then do post work blower door testing to prove that the upgrades work. They even rebate the $100 fee if you have a minimal amount of work done.

Remember the most efficient way to burn wood is not to burn it as you have reduced the heat demand.

Yes had the Home Performance program audit done , the sealed the seams in the attic and blew in another foot of insulation at just about the price I could do it for and they paid 1/2.

 

[aaajaws]

This is sounding more like a draft issue to me. Back puffing happens when the draft is weak and the combustibles light off in the box suddenly, having to open the ash drawer is another sign of air restriction, on a cold start i start my fire with my small wood on the bottom and the paper.. 2 sheets on top. I light it up with the door cracked open and my stove is taking off,. .. or wet wood, do you have a moisture meter and have you checked the moisture on a open face of a freshly split piece of wood.
How are you measuring stove top temp and cat temp

"or wet wood" I don't have a moisture meter but I built two connected, ventilated, south facing wood sheds, they hold a total of 9 cords. Wood staid nice and dry , seasoned for well over a year split and stacked in there. As far as draft with the pipe off the back for a deep cleaning there is a decent draft I can feel and the match test I see good flow. Of course on very cold days and stove has been off for a bit it is a bit harder to light with a 25 ft column of cold New Hampshire North Country air stacked up against it.

 

[aaajaws]

This is sounding more like a draft issue to me. Back puffing happens when the draft is weak and the combustibles light off in the box suddenly, having to open the ash drawer is another sign of air restriction, on a cold start i start my fire with my small wood on the bottom and the paper.. 2 sheets on top. I light it up with the door cracked open and my stove is taking off,. .. or wet wood, do you have a moisture meter and have you checked the moisture on a open face of a freshly split piece of wood.
How are you measuring stove top temp and cat temp

How are you measuring stove top temp and cat temp.... The top temp I measure at the exhaust outlet with a traditional dial magnetic gauge , as of right now I don't have a real way of measuring the CAT temps. I heard the is a designated whole in the back for a thermometer tip.... I will have to scout around for that .Any help of the location would be much appreciated .

 

[aaajaws]

This is sounding more like a draft issue to me. Back puffing happens when the draft is weak and the combustibles light off in the box suddenly, having to open the ash drawer is another sign of air restriction, on a cold start i start my fire with my small wood on the bottom and the paper.. 2 sheets on top. I light it up with the door cracked open and my stove is taking off,. .. or wet wood, do you have a moisture meter and have you checked the moisture on a open face of a freshly split piece of wood.
How are you measuring stove top temp and cat temp

Back puffing happens when the draft is weak, This is only when I have the CAT engaged and I try to dial down the air flow at night to extend the burn . Its not every night but sometimes when I do try and dial the air back