Kent outside air tile woodstove weak fire.

[Big big fire]

Installed a used Kent outside air tile fire. Stove was hardly used and very clean. New DSP vertical for 4.5' then 90 degree elbow, horizontal for 24" to Tee, then vertical for 19'(7'above shingles on 4/12 pitch). Chimney is all new and insulated 6". Fire starts with no issues but seems weak once the door is closed. Intake is wide open 3" fresh air plumbed in to stove. Tried burning with dry 2x4s and no difference. Seems that the intake air is blocked in the stove. Removed and looked inside with flashlight and mirror and appears to be clear and clean. Any guesses to why it seems starved for air?

 

[Big big fire]

This is the stove.

 

[Jan Pijpelink]

I had one of those. Loved it. Not being an expert, I might think the 90 degree in combination with the 2 feet horizontal might reduce the draft you need. @bholler ??

 

[Big big fire]

Thanks for the reply. I wonder about that but unfortunately its through a thick wall and that's as short as I can get it.

 

[coaly]

Is the horizontal pipe pitched upward toward the chimney at least 1/4 inch per foot? Tee sealed well? Does this model have a bypass damper at outlet? Possibly not opening fully to heat chimney?

The installation instructions allow up to .5 meter offset from straight up, which is about 20 inches. (if I have the correct instructions for your model) So center of pipe inside to center of pipe outside would be a lot more than 20 Inch offset. Probably over 30. Middle of page 4 if this is the correct manual;
(broken link removed to https://www.kent.co.nz/documents/Kent-Clean-Air-Freestanding-Instructions.pdf)

If so, that would need more like a 45* angle.

 

[Big big fire]

Is the horizontal pipe pitched upward toward the chimney at least 1/4 inch per foot? Tee sealed well? Does this model have a bypass damper at outlet? Possibly not opening fully to heat chimney?

The installation instructions allow up to .5 meter offset from straight up, which is about 20 inches. (if I have the correct instructions for your model) So center of pipe inside to center of pipe outside would be a lot more than 20 Inch offset. Probably over 30. Middle of page 4 if this is the correct manual;
(broken link removed to https://www.kent.co.nz/documents/Kent-Clean-Air-Freestanding-Instructions.pdf)

If so, that would need more like a 45* angle.

Thanks for the reply
The horizontal stove pipe is pitched upwards at 1/4"per 1' but the horizontal chimney(18") section is not as it is locked in to the Tee at 90 degrees. I wonder if I can force a pitch on it?
There is a handle that opens a bypass damper and it functions like new.
The center to center distance would be around 32". I'm not against adding 45s just not sure how I can make them fit. As the 90 is right up to the chimney adapter pipe(cut as short as possible already).

 

[moresnow]

Fire starts with no issues but seems weak once the door is closed. Intake is wide open 3" fresh air plumbed in to stove.

First inclination is that your fuel is not dry enough when you describe the fire dying with closing the loading door. Classic symptom.
Not performing on lumber chunks is very odd however?

Do you have a moisture meter to confirm the fuel moisture content?

Second thought is that I would unhook the fresh air supply (guessing a flex line from outdoors to stove? Describe.) and try again. Process of elimination.

Ditto on making sure the cap on your T is sealed/seated etc. correctly.


Your install looks/sounds like it should perform fine.

Sweet looking stoves. Always admired.

 

[Jan Pijpelink]

This stove does not come with an outdoor fresh air supply connection.

 

[Big big fire]

This stove does not come with an outdoor fresh air supply connection.

Yes this model does. It is the Outside Air Tile fire. The intake comes in underneath and the intake valve handle is below the door

 

[Jan Pijpelink]

Interesting. Never seen that one before. Must be one of their latest models.

 

[Big big fire]

Interesting. Never seen that one before. Must be one of their latest models.

Interesting. Never seen that one before. Must be one of their latest models.

My first wood stove and I'm new to these so im not to sure. Stamping shows made 1986

 

[coaly]

Trying oven dry wood took the fuel out of the equation.

Is that the correct manual?

If so, the 24 inch offset maximum is probably the issue.

Every stove has a recommended draft measured at the flue collar. The draft is a measurement of low pressure area that allows the higher atmospheric air pressure to push into the stove. So the hot gasses rising up the chimney create this low pressure area in flue, pipe and stove. Things that reduce draft are resistance to flow, the most being the intake opening and in your case the extended intake vent. But true atmospheric air pressure from outside makes up for lower pressure indoors from many things such as a tight home or exhaust fans (kitchen range fan or clothes dryer or any other vented appliances venting out of the home) reducing the pressure inside the house. The bypass damper reduces internal firebox resistance. Elbows, Tees, connector pipe length, and variable resistance from a flue pipe damper, and spark screen on outlet add to resistance. So the chimney height and differential temperature inside and outside of the flue, and air pressure given on any changing day increases draft, and all these other things take it away. There are formulas and tables to use to calculate NET draft when designing the system. A horizontal run adds resistance and this is calculated during testing. The manufacturer knows exactly how much resistance this adds and gives a maximum allowable. A stove that breathes easier can have much more resistance in the exhaust system, others become more critical.

The installer should measure the draft at stove collar when in doubt. This is measured in inches of water column. Some installation instructions give required draft. Then you know if you have sufficient draft. The chimney is what makes the stove go. No stove will work without the proper draft created by vent system. Increasing draft is normally done by raising chimney height, but there are limits, since as the hot gasses rise, they cool, reducing draft. So a short chimney benefits more and the increase in draft reduces with height. This can produce more draft to overcome the high resistance.

 

[Big big fire]

Thanks for the reply. Intersting stuff. I'm not sure if that is the right manual. I have not been able to find any installation manual for the tile fire stoves.
The only thing left for me to try is putting a small slope(1/4"per1') on the horizontal chimney pipe(18" section) and see if that helps a bit. Overall the stove is usable right now, I just know that's not it's operating to it's full potential.
It is warmer outside-3c/26f degrees. Hopefully improves as it gets colder.

 

[Jan Pijpelink]

Do you what year the stove was made?

 

[Big big fire]

1986

 

[Jan Pijpelink]

In that case, here is the correct manual. Coaly sent you the current manual.

 

[Big big fire]

This how it was installed except the chimney is about 84" above the roof.

 

[Jan Pijpelink]

I do not see the cold air intake.

 

[Big big fire]

I do not see the cold air intake.

Sorry that was not included in the original drawing. It is a 3" line that is approximately 6' long. I used steel ducting to keep the flow smooth.

 

[Jan Pijpelink]

Sorry that was not included in the original drawing. It is a 3" line that is approximately 6' long. I used steel ducting to keep the flow smooth.

Where is the outside air coming from?

 

[Big big fire]

In that case, here is the correct manual. Coaly sent you the current manual.

Good to have. Thanks

 

[Big big fire]

Where is the outside air coming from?

From outside the house, under the deck. The intake hood has wire mesh to stop animals but nothing restrictive

 

[Jan Pijpelink]

Never seen a Kent with an air intake connection below the firebox. Interesting.

 

[coldman]

We've got this same stove, a circa 1980s Kent Outside Air Tile Fire, purchased this fall and installed about a week ago. We're also having exactly the same problems that you are; we'll start a fire and get it going well with the bypass damper on top fully opened and the front door cracked just slightly. However, after fully closing the door, the flames will slowly die down and go out unless the door is slightly opened again, after which the fire will quickly take off again. We had a Kent Sherwood stove prior to this one, and that model had an adjustable sliding inlet air control located on the upper left hand corner of the stove, which is not on our stove. The Outside Air Tile Fire is likely a different manual from the regular tile fire, which operates like the Sherwood. It is my understanding that the Outside Air model was manufactured for use in mobile homes. If there weren't many sold in the US, that might account for the trouble we're having in finding the correct manual.