Fan Only Mode; Start - Up Procedure Anda; Furnace Operation; Furnace Start - Up - Goodman MH8 Installation Instructions Manual

F O M
AN NLY ODE
The normal operational sequence in fan only mode is as fol-
lows:
•
R and G thermostat contacts close, initiating a call for
fan.
•
Integrated control module performs safety circuit checks.
•
Circulator blower is energized on low heat speed.
Electronic air cleaner terminals are energized.
•
Circulator blower runs, integrated control module
monitors safety circuits continuously.
•
R and G thermostat contacts open, completing the call
for fan.
•
Circulator blower is de-energized. Electronic air cleaner
terminals are de-energized.
•
Furnace awaits the next call from thermostat.
S - P
TART UP ROCEDURE
Furnace must have a 115 VAC power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation. An interlock switch prevents furnace operation if the
blower door is not in place. Keep the blower access door in
place except for inspection and maintenance.
This furnace is also equipped with a self-diagnosing electronic
control module. In the event a furnace component is not operat-
ing properly, the control module LED will flash on and off in a
factory-programmed sequence, depending on the problem en-
countered. This light can be viewed through the observation
window in the blower access door. Refer to the Troubleshoot-
ing Chart for further explanation of the lighting codes.
Follow the start-up and adjustment items, refer to further infor-
mation in Section XIII, Operational Checks (see table of con-
tents, pages 2-3 for page number)..
F
URNACE OPERATION
Purge gas lines of air prior to start-up. Do not purge lines into
an enclosed burner compartment.
Check for leaks using an approved chloride-free soap and wa-
ter solution, an electronic combustible gas detector, or other
approved method. Verify that all required kits (propane gas,
high altitude, etc.) have been appropriately installed.
NOTE: An interlock switch prevents furnace operation if the
blower door is not in place. Keep the blower access doors in
place except for inspection and maintenance.
F S -
URNACE TART UP
1. Close the manual gas shutoff valve external to the furnace.
2. Turn off the electrical power to the furnace.
A A
ND

DJUSTMENT

S - P
TART UP ROCEDURE AND
3. Set the room thermostat to the lowest possible setting.
4. Remove the burner compartment door.
NOTE: This furnace is equipped with an ignition device which
automatically lights the burner. Do not try to light the burner by
hand.
5. White-Rodgers Model 36G22 or 36G54: Push the switch
to the OFF position.
Honeywell VR8215 or VR9205: Slide the switch to the
OFF position.
6. Wait five minutes to clear out any gas. Then smell for
gas, including near the floor.
7. If gas can be smelled following the five minute waiting
period in Step 6, immediately follow the instructions on
Page 3 of this manual. If you do not smell gas after five
minutes:
White-Rodgers Model 36G22 or 36G54: Push the switch
to the ON position.
Honeywell VR8215 or VR9205: Slide the switch to the
ON position.
8. Replace the door on the front of the furnace.
9. Open the manual gas valve external to the furnace.
10. Turn on the electrical power supply to the furnace.
11. Set the room thermostat to the desired temperature.
NOTE: There is an approximate 30 second delay between ther-
mostat energizing and burner firing.
F S
URNACE HUTDOWN
1. Set the thermostat to lowest setting.
2. Turn off the electrical power supply to the furnace.
3. Set the room thermostat to the lowest possible setting.
4. Remove the burner compartment door.
5. White-Rodgers Model 36G54: Push switch to the OFF
position.
Honeywell VR8215 or VR9205: Slide the switch to the
OFF position.
6. Close manual gas shutoff valve external to the furnace.
7. Replace the door on the unit.
G S P
AS UPPLY RESSURE
T
O PREVENT UNRELIABLE
INLET GAS SUPPLY PRESSURE
RATING PLATE WITH ALL
.
OPERATING
25
A
DJUSTMENT
M

EASUREMENT

CAUTION
OPERATION OR EQUIPMENT DAMAGE
MUST BE AS SPECIFIED ON
OTHER HOUSEHOLD GAS FIRED
,
THE
THE UNIT
APPLIANCES