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Complete Installation; Furnace Shutdown - Whirlpool WFM18 Installation Instructions Manual

80% single-stage multispeed gas furnace
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15. Remove the regulator cover screw from the high (HI) outlet
pressure regulator adjust tower and turn the screw clockwise
to increase the pressure or counterclockwise to decrease
16. Replace regulator cover screw.
17. Disconnect all electrical power and turn off the gas supply to
the system.
18. Remove the manometer hose from the hose barb fitting on
the outlet pressure boss.
19. For the Honeywell VR8215 valve, remove the ¹⁄₈" NPT hose
barb fitting from the outlet pressure tap. Replace the outlet
pressure boss plug and seal with a high quality thread sealer.
20. For the White-Rodgers 36G22 valve, tighten the outlet
pressure test screw to seal pressure port (clockwise, 7 in.-lb
21. Turn on the gas supply to the furnace at the manual gas
shutoff valve external to the furnace.
22. Reconnect all electrical power to the system.
23. Close thermostat R and W1/W2 contacts to provide a call for
24. Retest for leaks.
IMPORTANT: Bubbles forming indicate a leak. Turn off the
gas and repair all leaks immediately.
NOTE: For gas-to-gas conversion, consult your dealer for
appropriate conversion.

Complete Installation

IMPORTANT: Do not use this furnace if any part has been under
water. Immediately call a qualified person to inspect the furnace
and to replace any part of the control system and gas control
which has been under water.
1. Check that you have all of your tools.
2. Dispose of/recycle all packaging materials.
3. Check the furnace in its final location. Be sure the vent is not
Measure Temperature Rise
Air temperature rise is the temperature difference between the
supply and return air. The proper amount of temperature rise is
usually obtained when the unit is operated at the rated input with
the "as shipped" blower speed. If the correct amount of
temperature rise is not obtained, it may be necessary to change
the blower speed.
An incorrect temperature rise can cause condensing in or
overheating of the heat exchanger. Determine and adjust the
temperature rise as follows. The temperature rise must be within
the range specified on the rating plate or Specification Sheet
applicable to your model. Please contact your distributor for the
applicable Specification Sheet.
Temperature Rise Measurement
Rise = Supply air temperature - Return air temperature
A. Heat exchanger radiation
"line of sight"
B. Supply air
1. Operate the furnace with burners firing for approximately
15 minutes. Ensure that all the registers are open and all of
the duct dampers are in their final (fully or partially open)
2. Place the thermometers in the return and supply ducts as
close to the furnace as possible. Thermometers must not be
influenced by radiant heat by being able to "see" the heat
exchanger. Allow adequate time for thermometer readings to
3. Subtract the return air temperature from the supply air
temperature to determine the air temperature rise.
4. Adjust the temperature rise by adjusting the circulator blower
speed. Increase blower speed to reduce temperature rise.
Decrease blower speed to increase temperature rise. Refer to
"Circulator Blower Speed Adjustment" for speed changing
Final Checklist
Cycle the furnace with the thermostat at least 3 times. Verify
cooling and fan only operation.
Review the owner's manual with the homeowner and discuss
proper furnace operation and maintenance.
Leave literature packet near furnace.

Furnace Shutdown

1. Set the thermostat to the lowest setting.
The integrated control will close the gas control valve and
extinguish the flame. Following a 15-second delay, the
induced draft blower will be de-energized. After a 120-, 150-,
180- or 210-second delay period (field-selectable delay OFF
[90, 120, 150, 180] plus a 30-second ramp down), the
circulator blower deenergizes.
2. Remove the burner compartment door and move the furnace
gas control valve manual control to the OFF position.
3. Close the manual gas shutoff valve external to the furnace.
4. Replace the burner compartment door.
C. Supply air temperature
D. Return air temperature
E. Return air


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