I have a 100k btu boiler. My fire is always seems to be coming from very low in the pot around the outside and barely burning at all in the middle. There is just a black pile in the middle that is smoking. I have .05 draft. I have tried changing the combustion air but i am only open about a 1/2 to 3/4 inch and still the same problem. more air seems to be worse. Its causing alot of clinkers stuck to the pot. It is running on a power vent and its 6" reduced to 4" power vent. Someone told me thats too small. I still have .05 draft, isnt that what matters?

I got to looking and on my furnace the fire seems to be coming from the middle of the pot all the time and from about half way down the pot. But my boiler the fire is all coming up around the edge of the pot and is barely burning in the middle. It looks like the the fire comes rom near the bottom

I just had the top off last week and cleaned all the tubes and they are completely open.

No little nests that i know of lol. It just seems no matter what i do i get big black popcorn balls and hard clinkers stuck to the pot while my other stove is spotless in the pot

It seems like the furnace in the house has more air coming out of the top holes in the pot than the boiler in the shop does. It looks like the corn on the outside of the pot is burning fast but there is a cool spot in the middle that its not burning very much. Were there differnt models with more or less holes?

They will both have long burn times when it is cold, however the boiler probably has longer high fire burn times. How hong does the timer have to be set on and off to allow it to cool enough?

I have a 100k btu furnace in my house and a 100k btu boiler in my shop both burning the same corn. The one in my house gives me nice white ash with small hard clinkers and never anything stuck to the side of the pot. The one in my shop tho gives me some small clinkers and white ash but most of my ash is the black popcorn balls. Also i am always getting clinkers stuck on the side of the burn pot which i think may have something to do with the kind of ash im getting. My draft is at .04 and my combustion door about 1/3 or a little more open. The boiler has just been cleaned though the big top cover. What is causing my clinker build up and black ash?

Ok, my boiler was hooked up wrong for 2 years and wasnt maintaining a high enough temp and started to rust. It is now hooked up to maintain a 160 degree temp. When i did the complete cleaning the other day i noticed that there is alot of clumpy build up in the heat tubes. I used a wire brush on a drill to clean them but that didnt get it all out. Im wanting to use a more gressive cleaner but im afraid that since it started to rust fom being hooked up wrong i might cause a leak. Any thought on this? Is it repairable if i do get a leak?

Cn anyone show me a diagram of how to best plumb a corn boiler with a backup furnace and 2 zones?

Also i am adding on to my shop and wondering if there is a way to couple pex tubing together to extend it when it will be under cement.

Thanks. Found the problem. Apparently i didnt take the top off and clean it this spring like i usually do. (most likely because spring and planting came so fast this year.) I had cleaned the tubes from to bottom this year but there was too much laying on the top.

Anyone know where i can get one of them spiral cleaners for the tube like i have seen on here? I dont really like the idea of the hole saw.

UPDATE**** I wedged my draft cotroll shut so the fire would burn out faster today to clean the stove. When i came back i had a layer of clicker all the way around the pot so hard that i had to use a chisel to get it off. And the inside of the stove was starting to turn white again instead of black.

UPDATE**** I wedged my draft cotroll shut so the fire would burn out faster today to clean the stove. When i came back i had a layer of clicker all the way around the pot so hard that i had to use a chisel to get it off. And the inside of the stove was starting to turn white again instead of black

I have tried changing my combustion fan and it does burn lower on high fire but i still get big popcorn ash balls and the inside of the stove is pure black.What is causing all the clinker build up on the pot? It seems like they are blcking the air and causing some of my high fire problems. I am going to take the top off today and see what it looks like. Like i said, i am burning the same corn in both stoves so the corn is not the issue

I have everything set so the water returning to the boiler through the primary loop is about 10 to 15 degrees less than the water comong out which is around 160

I have a 100,000 btu boiler in my shop and 100,000 btu furnace in my house. The one in the house burns perfect. Nice clean pot sides, nice hard white clinkers and low ash, and very efficiant. My problem is the boiler in the shop. I am always getting clinkers stuck to the side of the pot and always have big globs of black ash coming out of the pot. The inside of the burn chamber is pure black and i usually have smoke coming out the exhaust that smells like when the fire is left to burn out. When i open the door on high fire i get a flame that comes out the door then goes back in. But then when its on low fire it burns down too low in the pot. My timer is at 2.5 and 8 and draft at .04. Auquastat is at 170 low and 195 high. Combustion air is about 1/4 open. Im burning the exact same corn in both stoves. Any idea what my problem is with the boiler?