adjusting draft on central boiler

[buck06]

I am looking for some information on adjusting the draft on my central boiler 5036, i run a plumbing and heating shop one day we were talking about setting draft on furnaces so i taught i would grab our combustion analyzer and test my wood boiler. There is a plate on my OWB that says to set draft between 0.01 and 0.02 and not to have it any higher than 0.02 When i tested it i was surprised to find it was between 0.05 and 0.07 I know i can adjust the draft on the door and messed with it for a while and it did not seem to help. i was just curious if anyone has ant ides on how to adjust the draft to slow it down Thanks Buck

 

[kodiakjoey]

I would like to know more about this too

 

[buck06]

I just talked to my dealer and he said that central boiler just came out with a baffle to slide in the chimney to reduce the opening from 8" to 5" it is used for the 40 - 50 -60 series classic boilers he said all you have to do is open the back of the chimney and slide it in past the T . he said the only problem he has heard is when you open the door it smokes a lot more than normal, on the plus side he said his customers have been reporting back to him saying that they have been using about 15 to 20 % less wood and the price for the baffle is around $ 35.00 not to bad for saving that much wood has anyone heard of this ?

 

[morewood]

Look at the CB site catalog. Chimney Tee restrictor Kit, Part #10970, looks like an empty spool with a large center section. If someone gets a price let me know, my dad and I both might be interested.....heck, I might try to find a local dealer and get it myself.

Shea

 

[buck06]

my dealer said he has them on hand for $ 35.00

 

[Fifelaker]

Man I'd rep you for this info but I have spread it all for today.

 

[CrappieKeith]

Indoor furnaces use a barometric draft regulator to adjust draft speeds.

 

[Iska3]

Hey Buck, I just sent you a rep for the info. I was fooling around with something like that two years ago. I cut a hole in to some scrap stainless pipe and inserted in to my T. I think I went down to 6 inches or a little less. If it helped or not I'm not so sure as far as saving wood because my burn times were much longer. I do know that you can not open your door unless the OWB is calling for heat because the added smoke is something else and even then it gets a bit nasty.

 

[buck06]

Good Morning Gentleman, Has any one ever removed the clean out cap on the back of the chimney and put a barometric draft damper in place of the cap to see if that would help to slow the draft down ?

 

[atlarge54]

A baro damper outdoors, seems like too many variables to function properly. I never even wanted one on an indoor burner, always thought they were a band-aid for a leaky stove.

I did put a manual chimney damper on my OWB for a while---probably more trouble than it was worth.

 

[Iska3]

I took off my rear cap in the nice weather and could actually use the OWB with the cap removed until the stronger winds came up. Then I tried an elbow connected to the end of the T pointing down and later an extension on it with a damper like I did with my old oil burner. My OBW faces north and south so once the high winds start from the north the smoke comes out the damper in my door. My door got so hot that I warped the first steel plate on the door. I tried to extend the baffle in the firebox to reduce the draft. I took three pieces of 6 inch steel I beam and spaced them on the floor between the baffle and the floor to reroute the draft. Keep in mind that you are outdoors… Not indoors.

The best luck that I had was with the U shaped stainless in the T with small holes cut in to it facing the upper part of the T.. but then you have all that smoke to deal with. Plus!! When the flames are really going strong on a hard burn, go out at night and watch the flame come out the damper on your door… I would think the excess heat by the door is why they had cracked in the past. But that’s just my thoughts.

Being from a Polish family, I even tried to place the first log crossways in the OWB so the draft in the door had to go up first and not go direct to the hot coals. I placed a brick on the ledge in front of the damper so the flames burned to the sides and not in the center..

I think when you have less draft, you might get longer burn time but less BTU of heat so you end up with longer cycle time.

Today is a low pressure day. Remove the end cap from the T and try it. Your OWB will still work and 99.9 percent of the smoke will go up your stack - the rest will come out the damper on your door.

 

[buck06]

I have often thought about putting a 8" x 6" reducer on the top of the chimney to slow the draft down, me being a plumber i am messing with my CL5036 boiler all the time changing pumps adding this and adding that and the one thing that i that made a HUGE difference is i added a 100 gallon storage tank in the house "old electric water heater" i plumbed it so from the boiler supply ties into the cold and out of the hot to the system in series and i took out my Grundfoss 15-58 and installed a grundfoss 26-99 my boiler is located 120' from my corn crib "house" on an average year i will burn about 12 to 16 cords of non split wood i have had my boiler for 4 years now. On average i would fill it every 12 hrs and i mean fill it ! with the changes i made this year i fill it every 24 hrs and when i do fill it there is still a large bed of hot coals left. Now i know this year is an exception to the rule being that it so warm, the only thing i have to say is i have never been able to fill it only once in 24 hrs. Is there anyone who has made any big changes that made a difference ?

 

[buck06]

i attached a drawing of my boiler set up for anyone who is interested in adding a hot water storage tank to there wood boiler system View attachment 224236

 

[Mogollon]

"and the one thing that i that made a HUGE difference is i added a 100 gallon storage tank in the house "

I added an Amtrol 40 gal with a heat exchanger to my system a few years back. Cut fuel consumption by about 20%. Wish I had more room to add more storage. Another benefit is that by running my water supply thru a manifold I can just heat DHW in the months I don't need to heat for the house.

 

[owbguy]

I have often thought about putting a 8" x 6" reducer on the top of the chimney to slow the draft down, me being a plumber i am messing with my CL5036 boiler all the time changing pumps adding this and adding that and the one thing that i that made a HUGE difference is i added a 100 gallon storage tank in the house "old electric water heater" i plumbed it so from the boiler supply ties into the cold and out of the hot to the system in series and i took out my Grundfoss 15-58 and installed a grundfoss 26-99 my boiler is located 120' from my corn crib "house" on an average year i will burn about 12 to 16 cords of non split wood i have had my boiler for 4 years now.

After trying to read that, about sums it up.

 

[mtfallsmikey]

Wonder how the CB restrictor works with a downdraft situation?