Backpuffing problem Dutchwest 2462

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Woodsman21769

New Member
Dec 19, 2021
1
Maryland
I recently purchased a Dutchwest model 2162 to replace my old Upland Model 207. I used the 207 for about 10 years, but its quite inefficient and also had a fairly large crack in the back panel because the heat plates on the rear were missing.

Here is my setup:
Unit is in the basement.
I have an all-masonry chimney which is on an exterior wall of the house.
When I installed the 207, I put in an un-insulated 7" stainless steel liner. The liner is about 24 ft. long.
The Dutchwest has an oval to 8" round adapter. I reduced to 7" after the adapter to connect to the 7" liner.
Before installing the Dutchwest, I changed all the rope seals including the one on the top at the catalytic chamber. The catalytic element was not replaced as it appears to be in decent condition.
The setup performed well for the 207 and I never had any smoke smell or downdraft except for a few times when there were very high winds.

The new Dutchwest 2462 works fine when the catalytic converter is being bypassed.
My problem is when I engage the catalytic converter. I get the stove temperature up to about 500 degrees before engaging it. The temperature probe on the top of the stove responds within a few minutes after the bypass is closed and reads between 700 and 1000 degrees.

When operating in catalytic mode, I have the primary air about 1/3 of the way open and the secondary air open 2 turns. I notice a smoke smell and have seen it backpuff a couple of times. The problem seems to be worse when it try to cut down on the primary air to make the fire burn longer.

If I bypass the converter, everything works fine.

Any suggestions on how to eliminate the backpuffing/smoke smell when in catalytic mode?
 
Not knowing what your manual says about flue diameters, my first guess is that the reducing (8"->7") could be the culprit. It may be that there's not enough draft to pull in enough air when the impedance is higher because of having the cat in the line the gases have to flow.
 
+1 on the reducer but put the reducer away from the stove. i had a 7 inch reducer for my 8 inch defiant about 4 feet away going into my chimney. and for the most part it worked. but if there is any type of buildup the stove would smoke when i changed to the 8 no problem at all stove worked even better. and that is with a 10 foot high chimney