Koker Draft Help

I'm running my Koker for the first time this year and I just got a manometer to see how it is drafting. I have an interior chimney running up the middle of my home, so I understand that gives me strong draft.

According to the Dwyer, draft is strong, so I adjusted my barometric damper to try and get it toward the Keystoker recommendation near .02-.03. It's hovering around .03-.04 now with my damper pretty much wide open all the time. I can't really open it much wider. Is that desirable? I noticed that the basement was pretty warm before with the radiant heat, but now it seems like that heat is getting sucked out and it's cooled down.

Are there any other adjustments I can make to lower the draft without drawing heat from the basement?

How open is your plate on the combustion blower, below the hopper. If you have that strong a draft, you should be able to have the intake for the fan at least half way open, probably more. If a strong draft is common for your situation, you may need a bigger damper or install two, in line with each other. You really need to get the draft reading down to about .025 so you don't risk the coal burning up into your hopper because that is where the stove will pull air from if it can't get it from the combustion blower. Another thing to think about is if it is windy when you are looking at the readings.

The combustion fan is open between third and a half. Will having that open immediately lower the draft or only when the fan is blowing?

How do you adjust that plate? Just loosen one of the screws and pull it open?

The combustion fan should be running all the time. The shutter pivots on a single screw (see picture). Try opening it so 3/4 of the inlet is open and see what it does.

There will probably be others that will also help you out. I don't have a problem keeping my draft at .025 or below, so I am not sure if the .03-.04 would solely be enough to make your fire travel back towards the hopper. But you are definitely losing too much heat up your chimney rather than keeping it in your stove to be transferred to the house. Not only is the .025 a safety point, it is the point at which Keystoker feels its koker runs efficiently.

If you do open your shutter, watch your draft on warm days. If your draft drops (usually does as it warms outside), you could pressurize your fire box with too much combustion air and cause CO to leak out into your house. Essentially, you would be forcing too much air into the fire box than the draft can evacuate.

Is the ash door the right place to check the draft on both Koker versions? I know it says to check draft in the hole for Direct Vent versions, but the manual for Koker with Thermostat doesn't say to check it there.

My damper is wide open and I've opened the combustion fan shutter all the way but draft is still about .05. It's a cold night...so maybe it's just that strong because of the temperature.

it will go up a bit when it's really cold and you're burning hot. A little higher is fine. i;ve seen mine up to .04-.06, sometimes there is nothing you can do, I have tall interior chimney also, and see higher draft at times.

I'll have to check my old manual, but you are right, I didn't see the location listed in the new manual either. I also have the thermostat/chimney model, just a couple years older than yours. As far as I know, Keystoker's manometer reading for kokers is always taken "over the fire" or in other words, at the ash pan door. Some stoves want the draft checked at the stove pipe, but the .025 we need should be taken from the fire box. It sounds like you have done all that can be done to manipulate draft. Search through the website here and you should find some threads the talk about adding a bigger barometric damper onto a given sized stove pipe tee. Maybe an 8" damper will get you down to where you need to be, but it sounds like WNY doesn't see anything critically wrong with your drafts, so you are probably ok. He has more experience with coal than I do.

One thing you can do to limit the amount of air that MAY be pulled through your hopper (again, hopper fire issue due to high drafting), is to keep your hopper full of coal, don't let it run too low. The coal will act as a "seal" to make it difficult for air to be drawn into and through the stoker. With mine, I always check in on it every day so for most of the winter when I am using a bag a day, I just throw a bag in every day to keep it topped off. The only time I let the hopper run down is at he very end so I don't have to remove too much coal when I shut it down in the spring.

roehrin wrote:Is the ash door the right place to check the draft on both Koker versions? I know it says to check draft in the hole for Direct Vent versions, but the manual for Koker with Thermostat doesn't say to check it there.

My damper is wide open and I've opened the combustion fan shutter all the way but draft is still about .05. It's a cold night...so maybe it's just that strong because of the temperature.

Actually I just checked draft again and now it's better. .02-.03. I still have my damper maxed out, so maybe it would be good to look at getting a bigger one for when heat is being called for.

I guess it just increases when the fire is roaring and it's frigid out and there's nothing that can be done. Last night was 12 degrees.

Just thought of something else, due to reading another similar thread. You can try to add fender washers under the adjustment nut, thus adding weight to it. That would help make the door more sensitive to opening, with the weight all the way to the middle.

Installed the koker lite also and it's a direct vent and the manual says .01 to.04 my stays right at .03 and stays little higher sometimes so u should be good just keep checking your fire bed that the red glow stays 2 inches for the coal mouth.