heatwithcoal wrote: Stove pipe increases from 6" to 8" after elbow exiting the stove.
Pacowy wrote:heatwithcoal wrote: Stove pipe increases from 6" to 8" after elbow exiting the stove.
AFAIK the increase in stove pipe size causes the speed with which the exhaust gases are moving to diminish. Having the increase occur at the bottom of a vertical section of pipe accentuates the accumulation of fly ash you get at that point. Without reworking all of the smoke pipe, if space permits you might be able to remedy this by replacing the first elbow with a tee, with one outlet from the tee facing the floor and forming a "trap" for some of the fly ash. Frequent checking/cleaning would still be needed, but this would leave the unit better able to withstand fly ash accumulation.
Rob R. wrote: I think it would work even better if the tee is a few inches larger than the flue outlet. Come off the furnace with 6" and go into an 8" tee, then run 6" to the chimney. The "slow down" should occur in the tee and drop the flyash into the "trap".