Don't know if this is the right place , backdrafting??

Reading around in here I see a lot of issues with coal stoves getting out of sorts and pumping the house full of CO. Ok I know it can happen with anything and don't really much care for the most part since the invention of the CO alarm. You have to be pretty dumb today living anywhere in the North not to have at least one anyway and digital readout is better.
Ok so what is the situation that lets a coal stove backdraft into the house to that extent? Nothing else seems to manage to do that that I am aware of so it interests me. I want to put a multifuel coal rig in but don't want to come home and find all my critters dead. I value them more than my neighbors. So what's the story.

Do a search on here, this has been discussed many times.

ANY Appliance burning Fuel Creates Carbon Monoxide. Natural Gas, Oil, Propane, Coal, etc....

If you have a poor draft chimney, a blockage, a severe wind, etc.. can reverse the flow in ANY chimney. It's not just COAL, I think because most coal burners have a BARO damper to regulate the draft on the stove (which most other units do not) that the fumes can possible leak out under the above circumstances, you have the chance of CO.

We have been running ours for over 3 years (one power vent) and one on the chimney and have not had any problems (knock on wood) with any of the CO detectors going off except if you open the door too long.

Most people have their Hot water tanks/furnaces in the basement and not in the living area, they can backdraft too, but probably go un-noticed if you don't have a CO detector in the Basement, most people put them in the living areas or near bedrooms.

You have to make sure you keep the chimney is clean of fly ash and the baro and draft measurements are set correctly and do the routine maintenance on the stove every season shutdown.

The Direct vents stoves have a Flume switch that will activate and trip the stove off line in case of a problem with power venting the gases.

Just like a wood stove, there is no real safety features that interlock any CO problems that could backdraft thru the draft controls or the door when you have to load it. (we burned wood for many years, I don't think we even had a CO detector?).

A hot chimney will be drawing well, but in the fall and spring, when the fire in the stove is smaller or the air is turned way down to keep from overheating the house, the amount of heat going up the chimney is less, so the chimney is cooler, the temperature differential between the outside air and the chimney's exhaust air is less.. all of these contribute to a weaker draft, and the potential for a draft reversal in the chimney.

The most likely scenario is take the above situation, the turn on the dryer, the bathroom fan, and maybe a kitchen exhaust fan... all pull air from the house, and push it outside.. IN a tight house with good windows, weather stripping and doors... the air for the exhaust fans has to come from somewhere.... the chimney can reverse and become a vent into the house..
So a carefull monitoring of exhaust fans, chimney draw and available outside air for fans and the stove is needed, especially in the warmer months..

Hope this makes sense..
Greg L

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OK, so it just seems overblown looking at it here. I never notice too much mention of problems like that on the wood sites. I have never seen the one in my bedroom break zero unless I had a raw propane flame going in an emergency. Every now and then I take it out and the garage and test it with a snowmobile. Theres some serious CO. Even then it takes a heck of a lot of it to reach the alarm point.

The difference with wood is that the wood smoke/exhaust usually really stinks, burns your nose and eyes.. bad enough to wake you up from sleeping.
Butthe exhaust and the CO from a coal fire is virtually odorless, so unless you have a good CO alarm, you could be in danger during possible backdraft.

Greg L.

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WNY wrote:I think because most coal burners have a BARO damper to regulate the draft on the stove (which most other units do not) that the fumes can possible leak out under the above circumstances, you have the chance of CO.

Would it be a good idea to block off the baro in the spring & fall? Understanding the additional heat that may be lost up the chimney.

spc wrote:Would it be a good idea to block off the baro in the spring & fall? Understanding the additional heat that may be lost up the chimney.

It would be best to disconnect the stove pipe from the chimney and block off the chimney. Remove the stove pipe and give it a good cleaning and store it in a dry area until next fall when you need to start the stove. Doing this will keep the moist summer air out of your stove and keep it from rusting.

gambler wrote:

spc wrote:Would it be a good idea to block off the baro in the spring & fall? Understanding the additional heat that may be lost up the chimney.

It would be best to disconnect the stove pipe from the chimney and block off the chimney. Remove the stove pipe and give it a good cleaning and store it in a dry area until next fall when you need to start the stove. Doing this will keep the moist summer air out of your stove and keep it from rusting.

I'm sorry for the misunderstanding. I am talking about when running the stove in the spring & fall, would it be a good idea to block the baro or remove & cap pipe, to eliminate back draft through the baro?

spc wrote:I'm sorry for the misunderstanding. I am talking about when running the stove in the spring & fall, would it be a good idea to block the baro or remove & cap pipe, to eliminate back draft through the baro?

No, my misunderstanding.
I certainly would not block off the baro. If you blocked it off and had a day when your chimney was drawing good you could end up with a hopper fire in your stove. I have operated my stove on a couple of 70* days in the fall and had no problems with draft reversal.

Another cause that I have seen mentioned here a few times is ash build up in the flue pipe. Depending on a few factors (coal quality, flue pipe config, draft, quantity burned) ash will need to be cleaned out a couple - three times during the heating season. Horizontal sections in the flue pipe before the thimble seem to be where it will lay the most. Plan on doing this and take advantage of those warm days that get sprinkled in during winter to let the fire die down and clean it out at that time.