Possible Negative Pressure Issues

[Automaton25]

Hello Everyone,

I have a Hearthstone Heritage which was professionally installed about a year ago. From the day of install, there has been issues with a little bit of smoke coming out when the door is opened, bypassing the catalytic converters helps, but does not reduce the issue. Recently, there have been big drafts coming down the chimney. The drafts are not connected with wind or temperature differentials as it has happened on calm and windy days and warmish (35) and cold (in the single digits). The installer said it is negative pressure and said to leave a door open for 10 minutes prior to starting a fire...This seems a little ridiculous to do it that long. I've never had a wood stove require that much, usually a couple minutes while you start the fire is sufficient. The draft can be so intense it will actually blow the fire out, even with the door open. When this happens, it blows smoke out of every opening in the stove (top flue port, back flue port, air intake, and out of the bottom of the stove). The downdraft is new as of about a month ago and has happened a few times since it started. Our furnace is not running at the time of starting the fire and all fans are off.

Any thoughts?

Cheers!

 

[jatoxico]

Where is the stove installed? Multi story house?

 

[Automaton25]

Where is the stove installed? Multi story house?

Main floor of a two story house. The room it is in has scissor truss ceilings with the highest point at about 20'. the second story opens to the vaulted area with three bedrooms off of it.

 

[moresnow]

What is the pipe/chimney setup from stove top to cap? Sounds frustrating!

 

[Automaton25]

What is the pipe/chimney setup from stove top to cap? Sounds frustrating!

I should also add that we never had a problem with the fireplace.

The flue comes out of the back (approximately 20" and turns 90 degrees and goes up the chimney. The cap has the usual screen on it, then a sort of trapezoidal box with screen over that. The stove was installed on the hearth in front of the existing fireplace. It is a tight fit, but it supposedly works.

Is there a chance that the chimney pipe was dropped too low and the horizontal pipe coming out of the back of the stove is either flat or sloping down before the 90 and causing problems?

It usually burns fine, especially when it is really hot, however, there is almost always a little burp of smoke. I wasn't concerned about it initially but now with the down draft, the smoke is starting to stain the soapstone and becoming an issue in the house.

 

[moresnow]

Smoke isn't known for going downhill well. The horizontal section should be gaining altitude (going up) at 1/4 inch per foot. This could be a large part of your issue. Add a few pics if you can.

 

[Automaton25]

Smoke isn't known for going downhill well. The horizontal section should be gaining altitude (going up) at 1/4 inch per foot. This could be a large part of your issue. Add a few pics if you can.

I attached a couple pictures, Sorry they aren't great. The stove is running and a little hot and the tolerances are tight. I don't know that the horizontal pile is flat or sloping down, I was just bringing it up.

 

[moresnow]

I'd be taking a look at the horizontal section when you get time. Think I'd check the pipe connection at the collar also. May just be me but it looks really out of square. May be harmless but?
What kind of liner goes up the chimney? Stainless flex liner? Can you get up top and check the screen on the cap? They are rather notorious for plugging. If you cant get up there use binoculars from the ground for a look.

Nice looking stove by the way.

 

[Automaton25]

I'd be taking a look at the horizontal section when you get time. Think I'd check the pipe connection at the collar also. May just be me but it looks really out of square. May be harmless but?
What kind of liner goes up the chimney? Stainless flex liner? Can you get up top and check the screen on the cap? They are rather notorious for plugging. If you cant get up there use binoculars from the ground for a look.

Nice looking stove by the way.

Thank you for the input! I'll check the screen tomorrow, there's snow on the roof so I'll use binoculars. If you want a picture, I can put a zoom on my camera and get one as well. I'm 90% sure the chimney liner is flex. It's still under warranty so I don't want to take too much apart, they are just being difficult.

Thank you, we whitewashed the brick and the mantle was home made using the Shou Sugi Ban technique on a beam remnant, I don't think it made it into the picture though.

 

[moresnow]

Sounds like you have a plan. Verifying a clean screen is a good start. Where abouts are you in Co? Just curious.
I am aware of another stove user who has some wonky draft issues related to his proximity to the nearby mountains.

 

[Automaton25]

Sounds like you have a plan. Verifying a clean screen is a good start. Where abouts are you in Co? Just curious.
I am aware of another stove user who has some wonky draft issues related to his proximity to the nearby mountains.

I am in Lakewood just east of green mountain and about 3 miles as the crow flies from the front range.

The mountains definitely mess with things, I just would have expected it sooner and with the fireplace as well (we burned that for 8 years as a heat source). I'm no professional though, we hired someone for a reason haha.

 

[Automaton25]

The screen looks clear from what I can see. I did notice that they cut a part of the sheet metal on my existing cap and replaced it with screen (this happens to be on the west side of the chimney where all the wind comes from. I attached a picture, but it is pretty terrible. If you guys need to see more, I can grab a real camera instead of my phone.

It is hard to see in the pictures, but all of the screen is intact.

 

[moresnow]

That setup is unfamiliar to me. Really tough to say if there is a problem up there without a close up look! I am going to request another gent to take a look at this thread.

 

[Automaton25]

That setup is unfamiliar to me. Really tough to say if there is a problem up there without a close up look! I am going to request another gent to take a look at this thread.

Thank you. There is a traditional circular cap with another screen under the rusty "decorative" piece.

 

[moresnow]

@bholler

If you get time this thread could use your opinion.

 

[bholler]

I have concerns.

1. That cap is probably to low and restricting the exhaust.

2. I am assuming there is an old prefab fireplace there which they put a plate over covering the cooling air vents.

3. There are probably combustibles directly behind that brick meaning you may very well have clearance to combustible issues with the stove.

4. Did they install a liner. If so did they allow for the cooling air to circulate through the old air cooled chimney.

 

[Automaton25]

I have concerns.

1. That cap is probably to low and restricting the exhaust.

2. I am assuming there is an old prefab fireplace there which they put a plate over covering the cooling air vents.

3. There are probably combustibles directly behind that brick meaning you may very well have clearance to combustible issues with the stove.

4. Did they install a liner. If so did they allow for the cooling air to circulate through the old air cooled chimney.

1. If it would help, I can jump on the roof and get a rough measurement for cap clearance.
2. There is/was an old prefab fireplace behind the black paneling. all of the refractory panels were left in place, but they did cut some of the metal out around the flue.
3. No permit was pulled, but two separate companies said it met code (I'm not familiar with the code for this stuff so I have no idea).
3. A new liner was installed.

Here is the blurb from the estimate"
Hearthstone Castleton 2020 EPA Certified Freestanding Wood Stove

Matte black / Front loading door
1.9 cubic foot fire box / 18” inch log length
❖ Flexible stainless-steel chimney relining system
6” Smooth-walled liner - approximately 25’ run

Insulated top and bottom / Top plate / Cap with spark-arresting screen

Tee with cap / Supports
❖ Firebox modifications
Remove smoke guard / Steel plate below flue opening
❖ Trim plate

Steel 39 1⁄4” W x 35 1⁄4” H / Cut-out for connector

❖ Mantel shield
❖ Setup / Delivery / Installation / Instructions / Adjustment
❖ Parts / Materials / Labor / Tax"

I hope some of this helps

 

[bholler]

1. If it would help, I can jump on the roof and get a rough measurement for cap clearance.
2. There is/was an old prefab fireplace behind the black paneling. all of the refractory panels were left in place, but they did cut some of the metal out around the flue.
3. No permit was pulled, but two separate companies said it met code (I'm not familiar with the code for this stuff so I have no idea).
3. A new liner was installed.

Here is the blurb from the estimate"
Hearthstone Castleton 2020 EPA Certified Freestanding Wood Stove

Matte black / Front loading door
1.9 cubic foot fire box / 18” inch log length
❖ Flexible stainless-steel chimney relining system
6” Smooth-walled liner - approximately 25’ run

Insulated top and bottom / Top plate / Cap with spark-arresting screen

Tee with cap / Supports
❖ Firebox modifications
Remove smoke guard / Steel plate below flue opening
❖ Trim plate

Steel 39 1⁄4” W x 35 1⁄4” H / Cut-out for connector

❖ Mantel shield
❖ Setup / Delivery / Installation / Instructions / Adjustment
❖ Parts / Materials / Labor / Tax"

I hope some of this helps

If they did cut the metal around the flue that is a huge problem unless it was just the smoke shield. The fact that they covered the vents on the fireplace is a big problem.

And going on the roof taking measuments and pics could help not sure what's going on without seeing it.

 

[Automaton25]

If they did cut the metal around the flue that is a huge problem unless it was just the smoke shield. The fact that they covered the vents on the fireplace is a big problem.

And going on the roof taking measuments and pics could help not sure what's going on without seeing it.

Here is a picture of the fireplace the night before it was installed. The light brown/tan piece right below the top vents is what they removed. Everything else, to my knowledge, was left in place except the part that closes off the flue. I'll get some measurements up top tomorrow

 

[bholler]

Here is a picture of the fireplace the night before it was installed. The light brown/tan piece right below the top vents is what they removed. Everything else, to my knowledge, was left in place except the part that closes off the flue. I'll get some measurements up top tomorrow

I don't see a pic

 

[Automaton25]

I don't see a pic

I'm sorry, I completely forgot to attach it.

 

[bholler]

I'm sorry, I completely forgot to attach it.

Yeah those vents cannot be obstructed in any way

 

[Automaton25]

Yeah those vents cannot be obstructed in any way

Is there anyway you can cite the fire code that is being violated? They cited NFPA 2016 in the quote. I believe you, I just want some ammo to fight with.

 

[bholler]

Is there anyway you can cite the fire code that is being violated? They cited NFPA 2016 in the quote. I believe you, I just want some ammo to fight with.

It isn't fire code it is manufacturers instructions for any fireplace with vents like yours.

 

[Automaton25]

It isn't fire code it is manufacturers instructions for any fireplace with vents like yours.

Ahh okay. So why are they still necessary with a new liner and no combustion taking place in the old firebox?