25
Dutchwest Sequoia
2001049
Care of the Catalytic Combustor
This wood heater contains a catalytic combustor, which
needs regular inspection and periodic replacement for
proper operation. Reminder: It is against the law in the
United States to operate this wood heater in a manner
inconsistent with operating instructions in this manual,
or if the catalytic element is deactivated or removed.
Under normal operating conditions, the catalytic com-
bustor should remain active for two to six years (de-
pending on the amount of wood burned). However, it
is important to monitor the combustor periodically to
ensure that it is functioning properly, as well as to de-
termine when it needs to be replaced. A non-functioning
combustor will result in a loss of heating efficiency, and
an increase in creosote and emissions.
The combustor should be visually inspected “in place”
for fly ash accumulation and physical damage three
times per year. Actual removal of the combustor is not
recommended unless a more detailed inspection is war-
ranted because of diminished performance as outlined
below.
The refractory package that housed the catalytic com-
bustor should be inspected annually for a buildup of fly
ash and cleaned if necessary. This may be done during
examination of the catalytic combustor.
When to Suspect a Combustor Problem
There are two ways to evaluate the performance of
your stove’s combustor. The first is to monitor the
temperatures recorded on the probe thermometer. A
properly functioning combustor should operate regularly
in the range of 800-1200°F (430-650°C). Combustor
temperatures consistently less than 800°F (430°C) are
a sign that examination of the combustor is advisable.
The second performance test is to observe the amount
of smoke leaving the chimney - both when the combus-
tor has achieved “light-off” and when it has not. Follow
this simple two-step procedure:
•
With a fire in the stove and damper closed to ac-
tivate the combustor, go outside and observe the
smoke leaving the chimney.
•
Then, open the stove damper and once again ob-
serve the smoke leaving the chimney.
Significantly more smoke should be observed after
the second step when the stove damper is open and
exhaust is not routed through the combustor. Be care-
ful not to confuse smoke with steam from wet wood,
however!
If either of these tests indicates a problem, consider
other possible factors as well.
Assess your present operating conditions. In spring or
fall, draft is weaker than it is in colder winter weather,
and a related change in stove performance may result.
Small hot fires are a good solution to sluggish perfor-
mance under these conditions.
Burning “green” (insufficiently seasoned) wood will re-
sult in poorer performance than when burning properly
seasoned fuel. You may have to run your stove hotter
(more air) to achieve good performance if you are burn-
ing green or wet wood. Also, any changes in operating
routine should be considered at this time as a possible
reason for changed performance.
Once you have ruled out any other possible causes
for a decline in performance, you may proceed with an
inspection of the catalyst.
Remove and Inspect the Combustor
Before you begin, observe the basic safety precautions
for working with dusty materials: always wear safety
glasses, a dust mask and gloves.
•
Remove the stove top plate. It is held in place by two
bolts. One bolt is accessible when you open the front
door and look upward toward the underside of the top
plate. The other bolt is most easily reached through the
side loading door. Remove the two bolts.
•
Lift the top plate off the stove. It is heavy, and you
may choose to have a helper assist you.
•
The combustor is located beneath the removable
refractory package, directly below the stove top near
the center of the stove.
ST746
Seneca
catalyst
1/9/03 djt
Combustor
Refractory
ST746
Fig. 27
A cutaway view of the combustor and its refractory
cover.
11. Tighten the anchor bolt. Tighten the anchor bolt lock
nut.
12. Replace the top.
•
Carefully remove the refractory package. It is
extremely delicate and should be handled as little as
possible.
•
For a visual inspection for blockage that can be
performed without removing the combustor, have an
assistant shine a bright flashlight beam up through the
combustor from inside the stove’s firebox.