Catalysts; Testing For Firebox Leakage - Lennox Hearth Products X-FIRES-WS-NG Installation And Operation Instructions Manual

CATALYSTS

Do not block the catalysts or the appliance outlet grill.
Blockage may cause high carbon monoxide levels
and/or breakage of the glass facia panel.
Do not operate the appliance with the catalyst units
removed.
Figure 9 - Catalysts and Outlet Grill
It is recommended that the catalysts are inspected for signs of damage
and dirt during routine servicing procedures . The expected life of the
catalysts is in excess of 11,000 hours (10 years of normal use) . After
this time the catalyst should be replaced .
If there are any deposits of dirt or soot on the catalysts they should be
clean ed with a soft brush and a vacuum cleaner . If removed for cleaning
ensure the seals are in good condition before replacing the catalyst . New
seals will usually be required .
The performance of the catalyst may be checked using a combustion
gas analyzer as follows .
IMPORTANT: The temperature of the gases emitted by the catalytic
converters reach very high temperatures (up to 700° F). Measuring
gas of this temperature may damage some types of gas analyzers. If
in doubt consult the equipment manufacturer.
16
WARNING
WARNING
DO NOT BLOCK
THESE AREAS
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE
Turn on the fireplace as per the operating instructions, and run at
maximum setting for 15 minutes . Position gas sample probe directly
over a cata lyst via the outlet grill, on top of the appliance . Record the
carbon diox ide (CO ) concentration and then the carbon monoxide (CO)
2
concentration as displayed by the analyzer - also noting the units in
which the values are expressed . Most analyzers display carbon dioxide
(CO ) concentrations in percentage (%) terms and carbon monoxide
2
concentration in parts per million (ppm) terms .
In order to calculate the combustion ratio for the appliance (CO/CO
is first necessary to express both gas concentrations in terms of per-
centage . To convert from parts per million (ppm) to a percentage (%)
divide the ppm figure by 10,000 . Examples : 35ppm = 0 .0035%, 15ppm
= 0 .0015%, 5ppm = 0 .0005% .
Now divide the concentration of carbon monoxide (CO) expressed in
percent by the concentration of carbon dioxide (CO
appliance combustion ratio .
CO (%)
CO (%) = ratio
2
The combustion ratio of the gasses emitted by the catalytic convertor
should not exceed 0 .0015 . If replacing, firstly, remove the glass door
assembly as described in section - Positioning of Field Assembled Parts.
The catalysts are located on the top of the internal firebox and can be
removed be unscrewing the retaining nuts securing the clamping plate .
Remove the catalysts and seals and discard .
Refit a new catalysts and seals in reverse order, ensure the catalysts
and door have good seals .

TESTING FOR FIREBOX LEAKAGE

Appliances that are several years old or have been extensively disman tled
should be checked for soundness . It is important that all the prod ucts
of combustion pass through the catalytic converters at the top of the
firebox before leaving the appliance .
The firebox is heated by lighting for a few minutes to provide a flow
through the firebox . The burner is then shut off and a smoke pellet or
match introduced at the base of the fire underneath the burner tray . Large
quantities of smoke will emerge from the top of the appliance, but none
should emerge from the joints or gasket faces, especially around the
door . It is important to note that the appliance can never be expect ed
to be 100% smoke tight and small quantities of smoke may be seen in
corners of joints and gasket faces etc without affecting safety when the
fire is in operation .
) it
2
) to obtain the
2