29
Intrepid II Woodburning Stove
2000966
The Catalytic Combustion System
Inspection and Cleaning
This wood heater includes a catalytic combustor, which
needs periodic inspection and replacement for proper
operation. In the United States, it is against the law to
operate this wood heater in a manner inconsistent with
the operating instructions in this manual, or if the cata-
lytic element is deactivated or removed.
Under normal operating conditions the catalytic element
should remain active for two to six years (depending 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 determine when it
needs to be replaced.
A probe thermostat, passing through the back of the
stove into the catalytic combustion chamber, automati
-
cally regulates the catalytic combustion air supply.
Deterioration of the probe may result in decreased
catalytic combustor performance.
A poorly-functioning catalytic combustion system 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. Do not remove the combustor unless a more
detailed inspection is warranted because of diminished
performance as outlined below, or to inspect the probe
thermostat.
The refractory package that houses the catalytic com-
bustor should be inspected annually for a buildup of flay
ash, and cleaned if necessary. This may be done during
examination of the combustor.
The probe thermostat should be inspected annually, or
more often if decreased catalytic combustion perfor-
mance is not due to a defective combustor.
When to Suspect a Combustion
System Problem
The best way to evaluate the performance of your In-
trepid II’s combustion system is to watch the amount of
smoke leaving the chimney - both when the combustor
has achieved “light-off” and when it has not. Follow this
procedure:
With a fire going and the combustor activated, with the
damper closed to send smoke through the combustor
as described in the Operation Section, go outside and
watch the smoke leaving the chimney.
Then, open the stove damper and again watch the
smoke leaving the chimney.
You should see significantly more smoke after the sec
-
ond step, when the stove damper is open and smoke
does not go through the combustor. However, do not
confuse smoke with steam form wet wood; steam dis-
appears rapidly in the air, smoke does not.
If this test indicates a problem, consider other possible
factors as well, such as the time of year or a change
in the quality of your fuel. In spring and fall, draft is
weaker than it is during colder winter weather, and fires
can burn sluggishly. Small, hot fires are a good solution
under these conditions.
“Green” (insufficiently seasoned) wood will burn more
poorly than properly seasoned fuel. You may have to
run your stove hotter (with more primary air) to achieve
good performance if you are burning green or wet
wood.
Also, consider any changes in your burning routine.
Once you have ruled out any other possible causes for
decline in performance, you may inspect the combus-
tor and probe. Wear a dust mask, safety glasses, and
gloves. Refer to Figure 46 as a guide.
1. Remove the andirons.
2. Reach inside the stove with a pair of pliers and turn
the two clamps that hold the fireback 90°. Turn the
left clamp clockwise, and the right clamp counter-
clockwise.
3. Grasp the fireback by its vertical ribs and remove it,
together with the attached throat hood. Pull the left
side out first.
4. Carefully clean the left and right exhaust pockets of
the refractory package. Use a shop vacuum, ideally
one with a very fine filter, and be careful to avoid
damaging the refractory material. This material can
stand high temperatures, but it is somewhat brittle
physically.
5. Carefully remove the refractory access panel in front
of the catalytic element.
6. Gently slide the catalytic element out of the refrac
-
tory chamber. Check the element and the bottom of
the chamber for a buildup of fly ash.
7. If the catalytic element is clogged, take it outdoors
for cleaning. Blow gently through the honeycomb. A
large amount of fly ash may come out of the ele
-
ment.
8. Inspect the element. Although small hairline cracks
will not affect performance, the element should be
largely intact. If the element is broken in pieces or
has large sections missing, replace it. Call your
dealer for a replacement element, part no. 160-
2521.