Could this be too much draft on our Heritage?

[JohnCusick]

Well, after some deliberation over the last 6 weeks while using our Hearthstone Heritage, I'm convinced that a damper in the stovepipe will help our operation. I wonder if I could run my observations by the collective wisdom here before I act to make changes.
Some history -
I did a new install of a used 2002 vintage Heritage in our home. It replaced a VC vigilant that just wore out after 27 years.
The stove sits on a tiled slab of the first floor 20x20 room and the flue line is straight up 25' to the chimney cap. The house is a converted post & beam structure/barn that is approx 20 x 50 with two bedrooms centrally located on the second floor (former hay loft).

The install detail are as follow.
22ga HeatFab stove pipe up 10' to a ceiling thimble then SuperPro stainless chimeny up 15' to cap.

When we started using the stove I was experiencing MAXIMUM stove top temps of 400 and that was trying hard. I could maybe get 650 at 5' up on the pipe (both read with magnetic thermometers). We are burning 12 - 16 month seasoned mixed red & white oak, hard maple, elm & poplar.

The usual burns were only 350 or so and I couldn't get coals to last more that 4 hours overnight.
Fires started GREAT from scratch, never any smoke our of either door.

That brings us to the last two week:
I started to notice that we were getting some smoke spilling out of either door when making a fire or loading. Then I realized while trying to heat the house up that I could easily get 550 to 600 stove top temps & 750 at the stovepipe. Hmmmm, big difference I said.
The smoke spilling out of the stove issue got WORSE.
So today I went up on the roof and found that the spark arrestor screen that we added to the cap (an OEM item) probably had 50-70% blockage of the screen openings. I cleaned it, (the pipe didn't have much buildup if any in it.)
We've had the stove running since - no smoke spilling out, and the stove top temps max out at 375-400.

I realize that the flames aggressively dance around as compared to a lazy pattern when the cap was cloged.
THis is all interesting as I have NO prior experience with this stove so I didn't have anything to judge things by.
It seemd like I have TOO STRONG of a draft/pull that I should be dampening down??
Would a damper help?
I'd like to know about them, brand, placement location etc before I jump.

Any help is much appreciated.

Toasty in Bethany...
John

 

[JohnCusick]

Thoughts anyone?

 

[Harley]

Can you cut back on the heat of the stovetop by just adjusting the primary air control? Are you getting these temps with the stove wide open or dampered down?

 

[JohnCusick]

Hmmm. Let's see.
The key points of my long winded post are this.
1. I would only see stovetop temps of 350 - 400 while the chimney cap screen was/is unclutter. I could get up to the low end of this range with the primary fully open, then see a creep up to 400 as I closed it down to 50%

2. I started seeing higher ( and gotten to quicker) stove top temps the past two weeks and then l I discovered the chimeny cap screen to be partially clogged.

 

[Highbeam]

I have a heritage and had clogging cap issues. A clean cap meant good controllable burns with the range of brisk to moderately slow burns. With cap plugged up it was just as if the primary air was cut back. The draft just got weaker which was a problem before any backpuffing happened. I ripped that screen out of the cap after I discovered that it was a maintenance item every 3 weeks. Everything is better now.

I have found with this Heritage that you don't want to just leave the primary air wide open until it gets up to temp. As soon as the new fire is rolling along, I cut back to 50% which doesn't really slow the fire down much at all. I leave it there until I get good secondary action and good stove temps and then set the draft back to a lower position. This is the quickest way to heat up my stove.

In my experience, wide open draft is not the way to heat this stove up.

Oh and you aren't supposed to run the new version of this stove at 600 continuously. The top target seems to be 500 with temporary overshoots being acceptable. Nobody really knows though.

 

[JohnCusick]

I guess the key for us is that we were NOT able to get stove top temps up above 400 before the cap started getting clogged, never mind 500-600. NEVER.
The most I saw out of this stove was 400.

 

[Todd]

What diameter is your chimney? Is it the same as your stove collar diameter? Sounds like your stack temps are high, a sure sign of overdrafting, but must be cooling off at the top to clog the screen. I would try a pipe damper, they are cheap and easy to install. Also check your ash pan seal and door gaskets.

 

[JohnCusick]

Hi Todd -
The collar, stovepipe & chimney pipe are all 6" ( we replaced the 8" that we had been using with our former VC Vigilant ).

Is there an ideal height to set the damper in when you have a striaght run up to a 10' high ceiling.

Thanks

 

[Todd]

I would say as close to the stove collar as practical. Maybe 12".

 

[Jags]

Just off the cuff here... but, if he is having problems with the cap clogging now.....wouldn't slowing down the draft with a damper increase this problem? I understand the wisdom of trying to bring the stove temp up, but I think that may make his clogging problem worse, which is a whole 'nuther issue, but an issue none the less.

 

[JohnCusick]

Interesting thought.
I found that when the spark arrestor screen was partially blocked we were getting higher chimney temps ( as measured by our condor magnetic dial 5 feet up). and I assume that slowing down the draft would match this condition = less buildup
I thought of taking the advice to remove the spark arrestor that we added. This is a Selkirk SuperPro chimney and the diamond mesh screen is loosly placed inside the cap...

 

[Jags]

Well, I think you have 2 distinct problems.
1. need to find a way to get stove temp up (which I think you are on the right path with a damper)

and 2. Clogging spark arrester. If the rest of the pipe appears clean (no build up), you may wish to remove or replace the arrester with a different product. If the pipe is also getting gunked up, all bets are off.

 

[JohnCusick]

I had the cap and top 4' section off yesterday. The sparkarrestor was CLOGGED, min 80%, lots of sticky gum crap at the cap joint. The interior of the pipe had a thin film of 'dust' on it, less than a 1/16 of an inch and a few stuck on flakes. I imagine I'd get less that 1 cup of soot if I scrubben the entire 25' run. I didn't even clean it.

SO I imagine if I increase both the stove & pipe temps, say stove to 450-550 and pipe in the 500-600 range regularly then I'd be inclined to get HOTTER exhaust at the cap?

 

[Bill]

Have you tested the moisture content of your firewood? Might be a little to moist yet. Sometimes wood isn't as dry as you think.

 

[Jags]

I had the cap and top 4' section off yesterday. The sparkarrestor was CLOGGED, min 80%, lots of sticky gum crap at the cap joint. The interior of the pipe had a thin film of 'dust' on it, less than a 1/16 of an inch and a few stuck on flakes. I imagine I'd get less that 1 cup of soot if I scrubben the entire 25' run. I didn't even clean it.

SO I imagine if I increase both the stove & pipe temps, say stove to 450-550 and pipe in the 500-600 range regularly then I'd be inclined to get HOTTER exhaust at the cap?

With a pipe damper you slow down exhaust gases which in turn keeps them in your stove longer, which results in a better, cleaner burn (hopefully) with more extracted btu's from you fuel. It doesn't increase pipe temp, or at least I have never seen that as a result. So even if it assists with problem #1 (increased stove temp), I think it will also adversely affect problem #2 (cap clogging). Maybe I am mixed up somewhere, but using a pipe damper has always proven (in my experience) to cool the pipe temp.

 

[JohnCusick]

We loaded 4 chord into the wood shed over the last three weeks, all following stretches of dry days, and everything I checked with my moisture meter was running between 12 & 18 % (I would grab 4-5" dia splits off the pile, axe split them in half, and checked the core). I must admit that I was pleasantly surprised. In a moment of doubt that my meter was sound I went to thepile of white oak just split last month & I got off the chart readings (>25%)
Nothing like stacking face cords to season in a East/West Line with open field around them.

I think the spark arrestor in this Superpro setup & I aren't goint to get to like each other... And to think that I just invested in 4 of these chimneys

 

[TMonter]

I had the cap and top 4’ section off yesterday. The sparkarrestor was CLOGGED, min 80%, lots of sticky gum crap at the cap joint.

Just FYI this isn't that uncommon John. I have the same problem with my Englander and Quad. For the englander I just took the bird screen out. For the Quad stainless liner I was unable to do this so I just clean the cap every 4-6 weeks and never have a draft problem.

 

[JohnCusick]

Thanks for sharing your experiences TMONTER.

I'm looking for a good damper recommmendation. I bought the chimney setup from Copperfield.

 

[Gooserider]

Some people have reduced the clogging problem by going after the screen with a pair of dykes and cutting out every other cross peice - effectively doubling the size of the holes. This still gives decent critter proofing, but it takes a lot longer to get any clogging since the openings are bigger and there is less surface for clogs to stick to.

John, You haven't answered the question a couple of people have asked - Can you control the amount of fire with the existing primary air control lever? Usually if the controls work, a damper isn't indicated. If they don't then a damper is more appropriate.

I believe Hearthstone even has a spec on this - if the draft exceeds 0.6" of water colum, then a damper is reccomended. Do you know anybody that does oil or gas furnace service? They are likely to have the meter needed to see what kind of draft you have.

However, I wouldn't be surprised to see you needed a damper, a 25' straight flue is in the range where it isn't unusual to need one.

Gooserider

 

[JohnCusick]

Ah the peace and quiet of eary mornings, eh Goose.
Thanks for the ideas.
I could contact an oil burner service tech I often work with on installs to see if he could measure it.
Regarding the functioning of the controls, there is a considerable effect on the fire between the two extreme positions. At fully open an aggressive yellow flame will usually spread throughout the entire charge of wood. Aflter the wood is charred and 'fully involved' as my firefighter cousin says, when I cut it back I see more involvement of upper burn tubes, and the aggressiveness of the burn subsides. The flame never dances around lazily, that is until the screen got blocked. I also HEAR a fair amount of draw noise whth the primary is in the most closed position as there is always a small area of opening at the slide plates.
Side note, We had the secondary burn tubes and risers out when we were replacing the ceramic blanket and I blew out the primary line also...

So is the screen needed for a 'spark arresting' and is there any code issue?
Draft not to exceed 0.6" of water column. What is the ideal range if I may ask.

Thanks again.
John

 

[Gooserider]

Ah the peace and quiet of eary mornings, eh Goose.
Thanks for the ideas.
I could contact an oil burner service tech I often work with on installs to see if he could measure it.
Regarding the functioning of the controls, there is a considerable effect on the fire between the two extreme positions. At fully open an aggressive yellow flame will usually spread throughout the entire charge of wood. Aflter the wood is charred and 'fully involved' as my firefighter cousin says, when I cut it back I see more involvement of upper burn tubes, and the aggressiveness of the burn subsides. The flame never dances around lazily, that is until the screen got blocked. I also HEAR a fair amount of draw noise whth the primary is in the most closed position as there is always a small area of opening at the slide plates.
Side note, We had the secondary burn tubes and risers out when we were replacing the ceramic blanket and I blew out the primary line also...

So is the screen needed for a 'spark arresting' and is there any code issue?
Draft not to exceed 0.6" of water column. What is the ideal range if I may ask.

Thanks again.
John

I'm not a morning person - I find I function best staying up late and sleeping in late - just wish the rest of the world would go along with that approach...

That your controls work is a pointer towards saying that you don't have a desperate need, but an agressive burn does...

In terms of the spark arresting, it is mostly a state or local ordinance type thing - generally places like CA that tend to go up if you glare at them have requirements for spark arresting, and places that aren't don't really talk about it. AFAIK there aren't any real issues in the New England states, either in terms of requirements, or sending out gov't officials to check... The other thing is that an EPA stove usually has enough obstacles between where the fire is and the flue that they don't tend to blow sparks out the chimney the way traditional fireplaces or old smoke dragon stoves do.

I'm not sure what the ideal range is for the WC measurement, I think it's around 0.3" to 0.5", but I'm not sure.

Gooserider