Chimney Draft Failure

This morning I knew it was gonna be warm and I sent the wife a text saying we will be under a "low draft watch" today.. Knowing she didn't have work I didn't prepare the furnace for a low draft condition. Well she went out shopping for a few hours and when she came home she sent me a message saying that the low temp alarm (set for 130) for the flue pipe was beeping (on my handy remote BBQ thermometer ). I immediately told her to go into the basement and look at the mano and sure enough, it was below 0 and the basement reeked of sulfur. SO, I had her hit the override switch for the draft inducer and took it up to a .03" WC. So no harm, no foul

My normal procedure for a warm day trying to idle the fire back is too -
1. Cut primary air to a sliver to keep a low and slow fire..
2. Open the MPD. (I usually leave it open unless its really cold and the baro can't keep my draft down to a .03"WC)
3. Open my secondary (over the fire air valve) to 50 - 100% depending on conditions outside.

*I've found that when I cut the primary air and give it more secondary it maintains draft. The secondary air doesn't aid much with combustion when running a low fire, but instead is just more heated air mass that goes up the chimney and keeps the draft. I've also added vents on two sides of the basement. These vents compensate for any (if any) stack effect going on in the basement from warm air going up thru the floor. The vents more or less keep atmospheric pressure between outside and the basement balanced since any negative pressure in the basement would cannablize draft pressure.

I'd like to hear what my other fellow coal burners do to keep a chimney draft under warm day outside conditions

Nice! You guys are fortunate to have good drafting chimneys Mine drafts good too, until it warms up outside. Since it runs along the side of the house and was built with solid blocks, I'm guessing it takes a long time to adjust to ambient temperatures outside. When there is a sudden rise in temperature outside, the air becomes warmer than the chimney. This is when my draft fails unless I keep the secondary air open to keep warm air going up the chimney. I discovered this last year while I was using a 26 foot high stove pipe for a chimney hahaha... When the Sun would hit it, it would draft crazy, then as soon as the Sun dipped under the hill, draft would cut way back.

michaelanthony wrote:...I will refrain from using the dryer,

True enough! Anything sucking air out such as a dryer will create low pressure around it, provided the space is tight (no way for make up air to get in). I notice this too if a window is opened on the first floor - better have the basements vents open!!

Hey Boots, is that a hand fed boiler? I might have to have one down the road at some point to use year round

perch wrote:i just bought my house i have no idea about the damper on the flue do i leave it wide open or cut it back its an old hand fired simplex multitherm it burns great the flue is almost wide open i just think alot of my heat is going up the chimney it burns real fast?

Hi perch, welcome to the forum .... I would advise you to start a new thread topic to draw more attention to get your questions answered. There are plenty of friendly people here willing to share their experience to help you ... I assume you are burning coal? More information is needed before advising what to do with your manual pipe damper. The more information we can get about your set up, the better we can offer advise..

jpete wrote:My chimney drafts like a pile of mud so toward the end of the season, I have to foil over the baro to make sure ALL the air goes the way it should.

On warmer days try running more secondary (over the fire) air. I've been able to maintain a draft even when it's approaching 60 degrees outside by doing that.