gfyy said:
As for the kind of wood it has been oak,cherry, maple, ash, hickory, just about everything. Most of it has been seasoned about 12-18 months. Some of it has been a little wet. About the cycling, if I leave my oil boiler off the damper hardly ever closes. If I run my oil boiler at the same time the damper is about 50/50. Open 20min closed 20min. I cleaned all of the pipes in the heat exchanger to the bare metal. The overhead section was a little tough, but I seemed to have gotten most of it. The refactory is a white color. I hope these are all good answers.
gfyy,
I don't see any smoking gun here. My thoughts are that it's most likely either that your wood is too wet or you're losing the heat up the stack or both.
If your wood is wet, (30% moisture or more) you won't get much heat from it. Those big 8"-16" rounds that the Greenwood loves burning take two full seasons to dry down to about 20% moisture. I learned this the hard way. I burned lots of big rounds that seemed to "go away" but not give off much heat. When I bought a moisture meter (cheap $24 two pin model on e-bay), I discovered that the rounds were running about 25-30% moisture after a year in my wood shed. Now I keep a two year supply and let the wood dry under a tarp the first year before moving it into the wood shed. I'd suggest getting a moisture meter so you can confirm that this is a problem or move on. You won't regret it because it rules out a variable. Drying your wood in the basement (close to the boiler but not too close) for three weeks will help if the problem is moisture. the radiant heat from the boiler makes quite a difference on moisture content.
If you still have a lot of creosote on the tubes, or if your draft is too strong, you are likely losing a lot of heat up the stack. If you don't have one yet, you should get a flue thermometer. Not the external magnetic type, but one with a probe that you can stick into the pipe, but still remove every couple of days to clean off, so you get accurate temperatures. (The thermometer will read 50 degrees low with a little coating of ash or creosote). If your stack temperature is running over 500F, you likely have too much draft or dirty tubes.
If the tubes are OK and you're running hot, then you should recheck the draft. My Seton runs .07-.10" under full fire. I have a 6" flue pipe into a masonry chimney. With clean tubes, dry wood(20%moisture or less), and running wide open, I will see temps of about 550 max.
Another possibility would be that your Greenwood is in fact undersized. You can probably estimate that from looking at what % of the time the 120,000BTU/hr oil boiler runs on cold days. If your oil boiler is running 75% of the time or more, then that could be the problem. (that's my uneducated opinion- I'm not an engineer or a heating professional)
I'm not sure what else to tell you. Maybe others here will have other ideas.
Mole