Matthaus wrote:From all the folks I have talked to looks like it is a factor of coal ash content more than anything. Once a month seems to be rather common for heavy use (more than 1500# per month) but it can be stretched to a longer interval by slightly reducing the draft at the breach. I would not go any lower than -.035" and as long as there are no signs of poor draft (wet hopper lid or slight sulpher smell) the base draft can go below -.01" with no ill effects.
The clean out option makes this a easy job and will require less than 2 minutes per cleaning, the economizers do not require removal or movement each time unless you want to.
Yep, I'm burning right around 1500 per month, and the cleanout is right around a one month interval.
Wish that easy cleanout option had been there when I bought mine...

but it's really not that big a deal to clean it out.
As for the amount of ash in the coal, I'm not really tracking that at his point, since this has been the first year and keeping the boiler lit has been the biggest priority, but I suspect that you're right about that.