Confused by Manometer - changes when door is open vs closed

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Bigeejakes

Member
Dec 8, 2019
13
MI
Hi Guys - so i've been running a englander 28-4000 for a couple of years and have a pretty good handle on how everything is running, and I'm getting it to produce great heat with around a 6 hour burn. I have been getting quite a bit of black crystal creosote, I would say 3-4 cups 2x per year on cleanings.

Setup as you go up the chimney: Stove- Manometer inserted (6" above stove) - Manual Pipe damper - Condar Probe thermometer - 90* elbow, 4ft horizontal through the masonry wall to T and then 28' insulated stainless liner through outside masonry chimney.

Manometer is a dwyer mark II, connected by 1/4" copper tubing (no connectors, just a hole drilled in the pipe and tube snugly fit.

Here's the goofy thing: My draft readings are running in the -.10 to -.15 range when the door is closed and no pipe damper being used (when stove is at operating temp... and if I open the door at that stage, I get a -.05 to -.07 reading. SO it seems that by closing the door it causes my draft readings to increase by about 2x.

Which one do I use? Based on how the stove burns and what I have read about the NC30 and the 28-4000 burn temps and air intake settings, I'm tempted to believe the door-open readings more than the door closed readings.

If i use the pipe damper to set it at -.05 with the door closed (this is a fully closed pipe damper setting with sub 30*F outside temps... I get a verrry slow burn, with some smoke smell coming into the house as the fire burns down (about 2.5-3 hours in).

Is this normal for my Dwyer Mark II... why would I get these larger draft numbers with the door closed?
 

Dieselhead

Minister of Fire
Feb 21, 2011
731
NE
More vacuum with the door closed is normal. with it open the chimney has a unlimited amount of air, with it closed the chimney has to “pull/vacuum” the air from the stove.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
30,096
central pa
Hi Guys - so i've been running a englander 28-4000 for a couple of years and have a pretty good handle on how everything is running, and I'm getting it to produce great heat with around a 6 hour burn. I have been getting quite a bit of black crystal creosote, I would say 3-4 cups 2x per year on cleanings.

Setup as you go up the chimney: Stove- Manometer inserted (6" above stove) - Manual Pipe damper - Condar Probe thermometer - 90* elbow, 4ft horizontal through the masonry wall to T and then 28' insulated stainless liner through outside masonry chimney.

Manometer is a dwyer mark II, connected by 1/4" copper tubing (no connectors, just a hole drilled in the pipe and tube snugly fit.

Here's the goofy thing: My draft readings are running in the -.10 to -.15 range when the door is closed and no pipe damper being used (when stove is at operating temp... and if I open the door at that stage, I get a -.05 to -.07 reading. SO it seems that by closing the door it causes my draft readings to increase by about 2x.

Which one do I use? Based on how the stove burns and what I have read about the NC30 and the 28-4000 burn temps and air intake settings, I'm tempted to believe the door-open readings more than the door closed readings.

If i use the pipe damper to set it at -.05 with the door closed (this is a fully closed pipe damper setting with sub 30*F outside temps... I get a verrry slow burn, with some smoke smell coming into the house as the fire burns down (about 2.5-3 hours in).

Is this normal for my Dwyer Mark II... why would I get these larger draft numbers with the door closed?
The door open readings mean nothing. Go by door closed
 

Dieselhead

Minister of Fire
Feb 21, 2011
731
NE
^^Yep^^