180-AF25 v1.11 per PE32 revs
March 15, 2021
Page 27
AF25
CATALYST MONITORING
CATALYTIC COMBUSTOR, CLEANING
Under certain conditions, ash particles may become attached to the face of the combustor. These may be
seen while the combustor is in the glowing stage, or when the fire is out. Any deposit on the visible face
of the combustor should be removed. Wait until the fire is out and the appliance is cold before performing
any cleaning. Brushing the combustor with a soft bristle paint brush will remove some deposits. Passing
a vacuum cleaner wand or brush near the face of the combustor will remove most deposits. (Hot ash in a
vacuum cleaner bag will burn, may melt the vacuum or cause a house fire. Exercise caution and never clean
the appliance when the appliance or ashes are hot.) Never scrape the combustor with any hard tool or brush.
Never run pipe cleaner through the individual cells of the combustor. This is not needed, and may do more
harm than good. Limit cleaning to the face of the combustor.
NOTE: Never remove a combustor without
approved combustor gasket in hand as original gasket will fall apart when removed from
appliance.
Remember to re-install the Flame Shield (the perforated plate) in same position it was found.
TIP: A hot fire will usually prove to be the best method of cleaning the combustor of deposits.
CATALYTIC COMBUSTOR, TESTING
Light the fire per the lighting instructions. After 1 hour of burning a well established fire, position the thermostat
knob to a medium - low burn rate setting. Allow 5 minutes for the catalytic thermometer to reach equiliburm
and observe the location of the indicator needle. A properly functioning combustor will have an active
temperture greater than 500F and the thermometer will read in the ACTIVE zone. A “tired” or “dead” combustor
will yield thermometer reading in the INACTIVE zone. Repeat this procedure for at least 3 burn cycles. If, after
several burn cycles, the thermometer will not indicate an ACTIVE reading your combustor may require cleaning
or replacement. If, after cleaning and reburning, your combustor is still not producing an ACTIVE reading you
should contact your Blaze King dealer for a replacement combustor. Note - It is also possible that the catalytic
thermometer itself may be functioning incorrectly. Before condemning the combustor, read CATALYTIC
THERMOMETER in OPERATING INSTRUCTIONS.
It is important to periodically monitor the operation of the catalytic combustor to ensure that it is functioning
properly. A non-functioning combustor will result in a loss of heating efficiency, and an increase in creosote
and emissions. Following is a list of items that should be checked on a periodic basis:
• Combustors should be visually inspected at least three times during the heating season to determine if
physical degradation has occurred. Actual removal of the combustor is not recommended unless more
detailed inspection is warranted because of decreased performance. Refer to “CATALYTIC COMBUSTOR
TROUBLESHOOTING” on next page.
• This catalytic heater is equipped with a temperature probe to monitor catalyst operation. Properly
functioning combustors typically maintain temperatures in excess of 500°F (indicated by the thermometer
needle in the active zone), and often reach temperatures in excess of 1000°F. If catalyst temperatures
fall below 500°F (indicated by the thermometer needle in the inactive zone), refer to next step and to
“CATALYTIC COMBUSTOR, TESTING” below.
• You can get an indication of whether the catalyst is working by comparing the amount of smoke leaving the
chimney when the smoke is going through the combustor and catalyst light-off has been achieved, to the
amount of smoke leaving the chimney when smoke is not routed through the combustor (bypass mode):
- Light the appliance as per the lighting instructions (see “LIGHTING THE FIRE”). With smoke routed
through the catalyst, go outside and observe the emissions leaving the chimney.
- Open the bypass mechanism, wait approximately 15 minutes, and again observe the emissions leaving
the chimney. Significantly more smoke will be seen when the exhaust is not routed through the combustor
(bypass mode). Some smoke may be visible shortly after you start the fire and shortly after reloading the
fire. Allow 20 to 30 minutes for the fire to stabilize before making observations.
DO NOT USE THE APPLIANCE WITHOUT A COMBUSTOR