Is this creosote normal?

[axlerosewood]

Below are pictures of my chimney. This is the part that goes through the wall then up the liner. Which is new this past October. Had a Summerair combo wood/oil (used) installed. Heats well but can't get the stack temperature above 250 degrees. Not even with the oil running. Chimney liner is 25' high inside clay flue. Seems to draft well. No smoke backpuffing issues. Burning dry maple mostly. always warm the flue with the oil burner before i light the fire. Just want experienced burners to see if this is normal for a relatively innefficient furnace. I think the huge fire box heat exchanger is the problem...by the time the smoke gets all the way to the back of the box over the oil burner and out it has cooled? Rarely do i damper down unless extremely cold out. Not a very air tight design to begin with. Maybe getting 3-4 hr burn time with 5-6 splits. Sometimes a coal bed left in the morning to start kindling with.

Any thoughts would be great!

 

[axlerosewood]

Anyone? Burn the same wood in my epa wood stove with no cresote. Is this safe?

 

[stee6043]

Looks like a LOT to me but I've never burned a non-gasser. My firebox has about this much in it but my flue has only dust...