black smoke out stack

[grinch5010]

Hey guys,

Couple of questions, have a 2x4 drop flue and having trouble getting a real hot fire some days. Using a small blower (one from a gas hotwater heater). It cant be more than 100cfm with about 15 feet of 8 inch stack. Should i try another 4 feet of stack before trying a bigger blower? I was thinking about a 263 cfm blower with a speed switch.
Suggestions?

[DrTimPerkins]

Black smoke out the stack.....I think your evaporator is trying to tell us the Cardinals haven't yet decided on a new Pope. :D

[Run Forest Run!]

Dr. Tim, you beat me to the punch! :lol:

[RileySugarbush]

Black smoke = not enough air. First check that your grate is not clogged and that your draft door is open. A AUF fan that is too small and tightly sealed could actually restrict air compared to a good natural draft.

[Tapped Out]

We have black smoke too.....no decision on a new 'SUGARMAKER'!! QUOTE=DrTimPerkins;213866]Black smoke out the stack.....I think your evaporator is trying to tell us the Cardinals haven't yet decided on a new Pope. :D[/QUOTE]

[bowhunter]

I agree with John.... 100 cfm is not enough air for a 2 x 4 if that's the only source of combustion air. That's only about half what's needed. You should get plenty of air on natural draft for a clean stack, but can't fire as hard as with a fan sized for the evaporator. Four more feet of stack will give you about 12-14% more air on natural draft.

[grinch5010]

Thanks guys! Added 2 feet of stack and getting a 265 cfm blower.