Low Draft Reading

This forum is for common products and questions such as chimney installations, CO detectors, coal bin designs and a variety of other general topics that do not fit into the other forums.
jimbob
New Member
Posts: 7
Joined: Fri. Jan. 31, 2014 12:51 am
Hot Air Coal Stoker Stove: Harman Super Magnum Stoker

Post Fri. Jan. 31, 2014 1:07 am

New to forum. Have a Harman Super Magnum Stoker. Just purchased the Dwyer Mark II Model 25 manometer. I have a RC Controls baro damper. Checked draft with the manometer. Owners manual says draft reading in the combustion box should be between .03 and .04. Mine read .03. The reading at the stove pipe below the damper reads 0. The manual says it should be between .06 to .08. If I hold the damper open the reading drops to negative .01. Can someone give me some guidance on what to check?
Thank You


User avatar
Lightning
Member
Posts: 8306
Joined: Wed. Nov. 16, 2011 9:51 am
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size
Location: Olean, NY

Post Fri. Jan. 31, 2014 4:08 am

Hi welcome to the forum.. You've come to the right place, someone will be along that knows stoker readings. In the meantime lets check the draft gauge. You have it mounted and leveled and is it calibrated to zero when its not hooked up to anything? Next, there is a high side port and low side port.. Take the reading with the low side port and leave the high side open. Keep in mind now that the negative value will be read on the positive side of the scale. This makes it possible to see values higher than -.05 since the negative side of the scale only goes that far.

Its critical that you have Carbon Monoxide alarms installed. If not, you should shut it down until you get at least two of them. By the looks of your readings, its possible you have positive pressure or close to it in the appliance cavity or flue pipe.. It's imperative that negative pressure is maintained in the entire system so that CO cannot leak out into the living space.

This much will get you started on diagnosis. Stay tuned as more will be along to help.. :D

User avatar
WNY
Member
Posts: 5849
Joined: Mon. Nov. 14, 2005 8:40 am
Hot Air Coal Stoker Stove: Keystoker 90K, Leisure Line Hyfire I
Coal Size/Type: Rice
Stove/Furnace Make: Keystoker, LL & CoalTrol
Stove/Furnace Model: 90K, Hyfire I, VF3000 Soon
Location: Cuba, NY
Contact:

Post Fri. Jan. 31, 2014 5:01 am

First, where are you reading the draft of the stove ? Just below the baro in the pipe is typcial.

If you stove is on idle and its warm outside, you will have lower draft. sometimes down around the -.01-.02. Sometimes you can't always get the exact recommended draft depending on the conditions.

Just remember the stove SHOULD be under Negative pressure, as long as it's not 0 or the opposite on your scale you should be ok.
That would be correct, when you OPEN the baro damper, you are reducing the draft on the stove and it will go to 0 or positive pressure. Which you do not want.
- Dave
Hyfire I & Keystoker 90K heating an 1890 Victorian
- Amsoil Authorized T1 Certified Dealer

jimbob
New Member
Posts: 7
Joined: Fri. Jan. 31, 2014 12:51 am
Hot Air Coal Stoker Stove: Harman Super Magnum Stoker

Post Fri. Jan. 31, 2014 7:26 am

Thank you Lightning and WNY for your responses. I have two CO detectors set up in the house. The stove has run fine for three years. This year I decided I should fine tune it. I have never used a manometer before. Yesterday I purchased the Dwyer Mark II model 25 manometer. I mounted it on to a board with the bottom screw not fully tightened so I could level it. I put the entire bottle of red oil in the fill plug. I set the gauge to zero. I put a plug on the high side outlet of manometer. If I do not plug the high side then the manometer reading will jump all the way to .2 with nothing connected to the stove yet and will not let me zero it. So I plugged the high side outlet. I connected the five feet of hose that came in the kit, to the low side outlet of the manometer. I attached the hose to a small piece of metal car brake line which I then placed through the hole that the dealer drilled in the stove pipe when the stove was installed a few years ago. The hole in the stove pipe is half way between the stove and the baro damper. I just checked it again this morning and it is reading between 0 - .01 with the damper baro damper closed.

User avatar
McGiever
Member
Posts: 6009
Joined: Sun. May. 02, 2010 11:26 pm
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek
Location: Junction of PA-OH-WV

Post Fri. Jan. 31, 2014 7:37 am

Whole bottle...no no.
Zero by adjusting the oil level being added while locked level to mounting.
Leave plug out too. ;)
SLOW AND STEADY WINS THE RACE

User avatar
Lightning
Member
Posts: 8306
Joined: Wed. Nov. 16, 2011 9:51 am
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size
Location: Olean, NY

Post Fri. Jan. 31, 2014 7:48 am

Ah, you over filled the gauge with the red oil. The high side port needs to be open to the room otherwise the low side can't compare it to the room's pressure. I think you will need to take it down and drain some out. The adjustment knob should be close to it's center of travel at zero reading so you have room to adjust it.

You may need to drain it, center the adjustment knob then carefully fill it back up till it reads zero.

The plugged high side is causing false readings.

jimbob
New Member
Posts: 7
Joined: Fri. Jan. 31, 2014 12:51 am
Hot Air Coal Stoker Stove: Harman Super Magnum Stoker

Post Fri. Jan. 31, 2014 7:56 am

Thanks guys. What is the best way to drain out the oil?

User avatar
Lightning
Member
Posts: 8306
Joined: Wed. Nov. 16, 2011 9:51 am
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size
Location: Olean, NY

Post Fri. Jan. 31, 2014 9:34 am

I have never done it. It could get messy. Try to capture the oil in something clean. You will likely need to put some back in. Try to drain small amounts at a time, while centering the adjustment knob. That would be my first attempt.


User avatar
Carbon12
Member
Posts: 2230
Joined: Tue. Oct. 11, 2011 6:53 pm
Stoker Coal Boiler: Keystoker KA-6
Coal Size/Type: Rice/Anthracite
Other Heating: Heat Pump/Forced Hot Air Oil Furnace
Location: Harrisburg, PA

Post Fri. Jan. 31, 2014 9:39 am

Somewhere I remember reading a Q tip is good for getting excess oil out. The instruction that came with the manometer describe how many turns to adjust the zeroing knob before adding oil. I don't have them in front of me but I think they said turn fully clockwise and then counterclockwise 4 full turns. Check the instructions to be sure.

Edit: strike that. I found the instructions online.

http://www.solutionsdirectonline.com/dwyer/pdf/dw ... 25-iom.pdf
Attachments
image.jpg
No matter where you go,......there you are.

jimbob
New Member
Posts: 7
Joined: Fri. Jan. 31, 2014 12:51 am
Hot Air Coal Stoker Stove: Harman Super Magnum Stoker

Post Fri. Jan. 31, 2014 9:24 pm

OK back from work. I drained the red oil out of the manometer through the drain plug with a ruber hose into a throw away plstic cup. Put just enough back in to zero it out. Just did my measurements again. In the stove pipe I am getting .04 and that is with the baro damper balance to to stay closed. The Harman manual says the draft should be between .06 - .08. In the combustion box im am measuring .03 - .04. That is exactly where the manual says it should be. That reading is with the blower flapper 3/4 way open. If I close it to 1/4 open then the reading is .04 - .05. This is also with the combistion blower on high. What do you think. Is that correct?

User avatar
coaledsweat
Site Moderator
Posts: 9827
Joined: Fri. Oct. 27, 2006 2:05 pm
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea
Location: Guilford, Connecticut

Post Sat. Feb. 01, 2014 3:51 pm

The baro won't open until it reaches it's setpoint. If it's set at .06, that is when it will start to crack open. What you describe sounds normal. When it gets colder you should see more draft and the damper start to vent. The baro's job is to limit total draft. If the chimney starts to pull .08-.10 on your stove pipe, the baro will stop it at .06. Drafting beyond the manufacturers limit would over fire the appliance and send your heat up the chimney.
Nothing is impossible for people who don't have to do it themselves.

jimbob
New Member
Posts: 7
Joined: Fri. Jan. 31, 2014 12:51 am
Hot Air Coal Stoker Stove: Harman Super Magnum Stoker

Post Sat. Feb. 01, 2014 5:08 pm

Thank you coaledsweat. I appreciate that advice. The manufacturer says to set the draft between .06 to .08. The weight on the RC Controls damper can be set on the left or right side of the gate. Does it matter?

User avatar
coaledsweat
Site Moderator
Posts: 9827
Joined: Fri. Oct. 27, 2006 2:05 pm
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea
Location: Guilford, Connecticut

Post Sat. Feb. 01, 2014 5:57 pm

Yes it matters. I believe the right side is for when it is mounted on a vertical flue and the left for a horizontal one. It should have a label on the flapper to explain that.
Nothing is impossible for people who don't have to do it themselves.

jimbob
New Member
Posts: 7
Joined: Fri. Jan. 31, 2014 12:51 am
Hot Air Coal Stoker Stove: Harman Super Magnum Stoker

Post Sat. Feb. 01, 2014 7:09 pm

Thanks mine is vertical and I do have it mounted on the right. They do not give you a centering arrow though to know where the weight really is on the scale.?

User avatar
coaledsweat
Site Moderator
Posts: 9827
Joined: Fri. Oct. 27, 2006 2:05 pm
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea
Location: Guilford, Connecticut

Post Sat. Feb. 01, 2014 8:14 pm

I just put an 8" baro in for a board member. It was marked with a curved line that matches the shape of the knob with numbers at each line. Yours should have some kind of markings, I never saw one without them.
Nothing is impossible for people who don't have to do it themselves.


Post Reply

Return to “Coal Bins, Chimneys, CO Detectors & Thermostats”