Cap on the flue/better fire?

Cap on the flue/better fire?

PostBy: MA_coal_fan On: Mon Nov 10, 2008 4:59 pm

Hi,

I'm fairly new to the coal stove world. I was getting some decent fires going in my Harmon Mark II, but lately I've been running into the situation where the fire starts going out after a couple of days. Last week, I had some 30 degree days and I had the coal stove roaring. Later in the week, the temperature got up to the 60s, ash built up, the coals died and the fire went out. The outside temp. stayed in the 60s, so I didn't try getting the fire going until today.

Temp today is in the 40s. It's very hard to get the fire going. I started a fire with the match-light charcoals, but they started going out. I wondered if I'm not getting a good draft because maybe some leaves got into the flue.

Several questions:

1. How much effect do warmer days have on draft? As I said, it seems my draft was fine on the 30-degree days and then got worse as the temp warmed up.

2. How important is it to have a cap on the flue(s) when burning coal? Someone told me somewhere that coal fires definitely need the cap.

3. Could leaves be causing a lack of draft? Or would it be some other problem? Is it an adjustment needed on the barometric draft control?
MA_coal_fan
 
Stove/Furnace Make: Harman
Stove/Furnace Model: MKII

Re: Cap on the flue/better fire?

PostBy: Wood'nCoal On: Mon Nov 10, 2008 6:16 pm

Hi Fan and welcome to the forum.

1. How much effect do warmer days have on draft? As I said, it seems my draft was fine on the 30-degree days and then got worse as the temp warmed up.


The chimney will tend to draft less as the outside temperature rises. The colder it is outside-the more that hot combustion from the stove will want to exit the chimney. If my stove is not burning and it's cold at night and then gets warm during the day my chimney will reverse draft once the outside temperature rises above the temperature inside the chimney.

2. How important is it to have a cap on the flue(s) when burning coal? Someone told me somewhere that coal fires definitely need the cap.


The cap is useful in helping to prevent a draft-reversal caused by a gust of wind. It also prevents rainwater from entering the chimney as well as any errant squirrels and birds. It is not a requirement for coal burning.

3. Could leaves be causing a lack of draft? Or would it be some other problem? Is it an adjustment needed on the barometric draft control?


I hope you cleaned the chimney or at least inspected it before lighting the stove. I would doubt it's leaves, there would have to be a ton of them in there to cause a problem. The baro damper needs to be set to limit max. draft of the stove. I run my Mark I at -.05" WC. You need a manometer to check this, there are threads on the forum about that.

Remember the warmer the chimney-the more it will draft. Before lighting a coal fire in the Mark II you should warm up the chimney by burning a small wood fire in the stove. Once everything is warmed up start to add the coal slowly. When lighting my stove I use charcoal soaked with charcoal lighter fluid, I cover the baro with foil and leave the ash door open until the chimney is warmed up.

Read here:

How to Light a Hand Fired Coal Stove

Hope this helps out.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Cap on the flue/better fire?

PostBy: MA_coal_fan On: Mon Nov 10, 2008 6:26 pm

Great. Thanks a lot for the info, Wood n Coal. Perhaps the warming up the chimney has been the problem. I'll try that out. And to answer your question, yes, I had the chimney cleaned toward the end of the heating season last year. I only ran my stove a couple of times after that.
MA_coal_fan
 
Stove/Furnace Make: Harman
Stove/Furnace Model: MKII

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Re: Cap on the flue/better fire?

PostBy: Dallas On: Mon Nov 10, 2008 9:12 pm

It sounds to me like you haven't shaken the ashes down and/or they have your grates blocked, so no combustion air can get up through the coal.
Dallas
 
Hand Fed Coal Stove: Modified Russo C-35
Other Heating: Oil Hot Air
Stove/Furnace Make: Russo
Stove/Furnace Model: Modified C-35

Re: Cap on the flue/better fire?

PostBy: Berlin On: Tue Nov 11, 2008 11:26 pm

"The cap is useful in helping to prevent a draft-reversal caused by a gust of wind" in chimneys with this problem i've found them to make hardly any difference; in addition, caps are good as soot-catchers (when burning wood) and as draft-reducers. As woodncoal said, however, they will keep leaves/birds/animals out of the chimney as well as some water.
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Cap on the flue/better fire?

PostBy: oliver power On: Tue Nov 11, 2008 11:43 pm

To add to the chimney cap responces , I also found that a chimney caps helps with burning coal on them low preasure atmosphere days. The fancy caps are not the kind you want. The fancy caps will hinder the coal fire. The cap needs to be as simple as a flat hat above the chimney.
oliver power
 
Stoker Coal Boiler: KEYSTOKER Kaa-2
Hand Fed Coal Stove: Hitzer 50-93 & 30-95, Vigilant (pre-Vigilant-II)
Baseburners & Antiques: MANY (Mostly when burning wood)
Stove/Furnace Make: HITZER / KEYSTOKER
Stove/Furnace Model: 50-93 & 30-95 , Kaa-2

Re: Cap on the flue/better fire?

PostBy: Wood'nCoal On: Wed Nov 12, 2008 7:27 am

caps are good as soot-catchers (when burning wood)


Agreed, been there, done that.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Visit Hitzer Stoves