176230-BIM-A-0206
16
Unitary Products Group
HOT SURFACE PILOT INSTRUCTIONS
To adjust the pilot flame:
1.
Remove the pilot adjustment cover screw.
2.
Adjust the pilot adjustment screw to achieve the proper
pilot flame.
3.
The pilot flame should envelope 3/8” of the end of the
flame sensor and not contain any yellow color, see Fig-
ure 12.
4.
Replace the pilot adjustment cover screw after the pilot
flame is set.
To check, adjust or remove the hot surface pilot assembly,
CLOSE THE MAIN MANUAL SHUT-OFF VALVE AND SHUT
OFF ALL POWER TO THE UNIT.
1.
Disconnect the wiring from the gas valve to the hot sur-
face pilot assembly.
2.
Remove the two (2) #8 screws holding the hot surface
pilot assembly in place.
3.
Remove the hot surface pilot assembly.
To remove the hot surface ignitor and flame sensor assem-
bly:
1.
Remove the clip attaching the ignitor and sensor assem-
bly as shown in Figure 13.
2.
Lift the pilot and sensor from the assembly. Care must be
taken not to damage the pilot or sensor when removing
this assembly.
ADJUSTMENT OF TEMPERATURE RISE
After about 20 minutes of operation, determine the furnace
temperature rise. Take readings of both the return air and the
heated air in the ducts about six feet from the furnace where
they will not be affected by radiant heat.
The temperature rise (or temperature difference between the
return air and the heated air from the furnace) must lie within
the range shown on the rating plate and the data in Tables 3
and 4.
After the temperature rise has been determined, the CFM can
be calculated as follows:
DIRECT DRIVE BLOWER
All units, with the exception of the 2 Ton, have direct drive,
constant CFM blower motors. Refer to the unit wiring dia-
gram, Table 1 for the desired cooling CFM. Heating CFM is
preset at the factory. For the 2 Ton unit, refer to the wiring dia-
gram to connect the blower motor for the desired CFM.
CHECKING GAS INPUT
NATURAL GAS
1.
Turn off all other gas appliances connected to the gas
meter.
2.
With the furnace turned on, measure the time needed for
one revolution of the hand on the smallest dial on the
meter. A typical gas meter usually has a 1/2 or a 1 cubic
foot test dial.
3.
Using the number of seconds for each revolution and the
size of the test dial increment, find the cubic feet of gas
consumed per hour from Table 11.
FIGURE 12 - PROPER FLAME ADJUSTMENT
3 / 8
FIGURE 13 - IGNITOR AND FLAME SENSOR
ASSEMBLY
Degrees F Temp Rise
BTUH Output
1.08
CFM
×
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=
OR
CFM
BTUH Output
1.08
Degrees F Temp Rise
×
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=
