Tempstar F97CMN Installation, Start-Up, Operating And Service And Maintenance Instructions page 55

F97CMN and G97CMN: Installation, Start-up, Operating and Service and Maintenance Instructions
1. Place thermometers in return and supply ducts as near furnace as
possible. Be sure thermometers do not see heat exchanger so that
radiant heat does not affect readings. This practice is particularly
important with straight-run ducts.
2. When thermometer readings
temperature from supply-air temperature to determine air
temperature rise.
NOTE: Temperature rise can be determined for Minimum Heat,
Intermediate Heat and Maximum Heat operation by locking the furnace
in each mode of operation. The mode of operation is based on the
position of Set-up switch SW1-2 and SW4-2 on the furnace control
board.
The furnace is capable of automatically providing proper airflow to
maintain the temperature rise within the range specified on furnace
rating plate. If temperature rise is outside this range, proceed as follows:
1. Check gas input for minimum, intermediate and maximum heat
operation.
2. Check derate for altitude if applicable.
3. Check all return and supply ducts for excessive restrictions causing
static pressure greater than 0.5-in. w.c.
4. Ensure Min/Int Heat Rise Adjust switch SW1-3 on furnace control
is in ON position when a bypass humidifier is used. See
for switch location.
5. Check Troubleshooting Guide for Variable-Speed Step Modulating
Condensing Furnaces.
6. Verify correct model plug is installed.
To lock the furnace in Minimum Heat:
1. Turn SW1-2 ON at the furnace control. Setup switch SW4-2 must
be OFF.
2. Connect a jumper across R and W/W1 at the thermostat terminals at
the furnace control.
3. Allow the burners to ignite and the blower to turn on.
4. Allow the supply temperature to stabilize and verify the proper rise
range.
If the temperature rise is too high or too low in Minimum Heat:
1. Remove jumpers from R and W/W1.
2. Wait until the blower off delay is completed.
3. Turn 115 VAC power off.
4. Check the position of setup switch SW1-3. When set to ON, airflow
is raised 18% for Minimum Heat and for Intermediate Heat.
Factory default position is OFF.
5. Turn 115 VAC power on.
6. Re-check Minimum Heat Temperature Rise
To lock the furnace in Intermediate Heat:
1. Turn SW1-2 OFF and SW4-2 ON at the furnace control.
2. Connect a jumper across R and W/W1 at the thermostat terminals at
the furnace control.
3. Allow the burners to ignite and the blower to turn on.
4. Allow the supply temperature to stabilize and verify the proper rise
range.
If the temperature rise is too high or too low in Intermediate Heat:
1. Remove jumpers from R and W/W1.
2. Wait until the blower off delay is completed.
3. Turn 115 VAC power off.
4. Check the position of setup switch SW1-3. When set to ON, airflow
is raised 18% for Minimum Heat and for Intermediate Heat.
Factory default position is OFF.
5. Turn 115 VAC power on.
6. Re-check Minimum Heat Temperature Rise.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
stabilize, subtract return-air
Table 58
To lock the furnace in Maximum Heat:
1. Connect a jumper across R and W/W1 and W2 at the thermostat
terminals at the furnace control.
2. Allow the burners to ignite and the blower to turn on.
3. Allow the supply temperature to stabilize and verify the proper rise
range.
If the temperature rise is too high or too low in Maximum Heat:
1. Remove jumpers from R and W/W1 and W2.
2. Wait until the blower off delay is completed.
3. Turn 115 VAC power off.
4. Check the position of setup switch SW1-4. When set to OFF and
SW1-3 is set to OFF, airflow is raised 10% for Minimum Heat,
7.5% for Intermediate Heat and 17.5% for Maximum Heat. Factory
default position is ON. If SW1-3 is ON and SW1-4 is OFF, airflow
is raised 18% for Minimum and Intermediate heat and 10% for
Maximum Heat.
5. Turn 115 VAC power on.
6. Re-check Maximum Heat Temperature Rise.
After the temperature rise has been verified:
1. Remove jumpers from thermostat terminals.
2. Allow the blower off delay to complete.
3. Turn set-up switches SW1-2 and SW4-2 to the OFF position unless
two-stage thermostat operation is desired, see
4. Proceed to "Adjust Blower Off Delay" or install blower door if
complete.
!
FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Reinstall manifold pressure tap plug in gas valve to prevent gas leak.
!
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced furnace life.
Recheck temperature rise. It must be within limits specified on the
rating plate. Recommended operation is at the mid-point of rise range
or slightly above.
Adjust Blower Off Delay (Heat Mode)
a. Remove blower door if installed.
b. Turn Dip switch SW-7 or SW-8 ON or OFF for desired blower
off delay, see Table 12
Table 18 – Blower Off Delay Setup Switch
DESIRED HEATING MODE
BLOWER OFF DELAY (SEC.)
90
120
150
180
Adjust Cooling Airflow – High-Speed and
Low-Speed Cooling
The ECM blower can be adjusted for a range of airflow for low-speed or
high-speed cooling, see Table 5
Fig. 58 - Furnace Setup Switches and Descriptions. Depending on the
55
Fig. 58.
WARNING
CAUTION
and Fig. 36, Fig. 58 andFig. 72.)
SETUP SWITCH
(SW1-7 AND -8)
POSITION
SW1-7
OFF
ON
OFF
ON
- Air Delivery - CFM (With Filter) and
SW1-8
OFF
OFF
ON
ON