joeq wrote:Lee, I do have a manometer, and set it where Surdiac recommends, (approx. -.04). I'm just wondering when the ash accumulates through the nitetime hrs, it (the draft) slowly goes away.
Yes, it very well could be but the cause could be a few different things. It sounds like ash build up since the symptoms reappear after a week, the bypassing air condition I brought up earlier.. It could also be that once the coal bed accumulates some ash that can't be cleared (like around the grate frame) you need to set your primary air a little higher to compensate. And also, if you are getting a yoyo effect of draft pressure causing variable heat output the barometric damper may help aid all of this. SO, don't try to fix everything at once.. Take one possibility at a time and do your best to fix it. Sometimes it takes some trial and error
joeq wrote:my question to both of you is how often do you need to remove ash accumulation, not only in your burning coal bed, but inside your pipes around your dampers? Not sure of your set-ups, but I think I remember you (Lee) having an MPD. Do you run it mostly closed, and does it clog up frequently during the burning season? Or can you make it through the winter?
Normally, fly ash in the pipe only needs to be cleared halfway thru the heating season and then again at the end of the heating season for a hand fed. I have a MPD but only use it occasionally. I'm a baro believer, I rely on the baro 99% of the time. Its the automatic regulation of the draft pressure I spoke of earlier that may help your issue. You said you set draft pressure at -.04 you use the MPD to do that? MPDs aren't good at holding a set pressure. As the chimney cools after burn off of volatiles, the draft weakens. This is when the MPD would need to be adjusted back to -.04 otherwise it will continue to decline since its a "fixed" restriction. I know that got hairy lol but that's the nuts and bolts of it.