background image

SERVICE AND TECHNICAL SUPPORT MANUAL

Gas Furnace: (F/G)9MVE

Specifications  subject to change without notice.

14

440 04 4801 03

Adjust Thermostat Heat Anticipator

a. Mechanical thermostat.  Set thermostat heat

anticipator to match the amp. draw of the electrical

components in the R

W/W1 circuit. Accurate amp.

draw readings can be obtained at the wires normally

connected to thermostat subbase terminals, R and W.

The thermostat anticipator should NOT be in the

circuit while measuring current.

(1.) Set SW1

2 switch on furnace control board to

ON.

(2.) Remove thermostat from subbase or from wall.
(3.) Connect an amp. meter as shown in 

Figure 6

across the R and W subbase terminals or R and

W wires at wall.

(4.) Record amp. draw across terminals when

furnace is in low heat and after blower starts.

(5.) Set heat anticipator on thermostat per thermostat

instructions and install on subbase or wall.

(6.)  Turn SW1

2 switch OFF.

(7.) Install blower door.

b. Electronic thermostat: Set cycle rate for 3 cycles per

hr.

Figure 6

Amp. Draw Check with Ammeter

A96316

R Y W G

10 TURNS

THERMOSTAT SUBBASE

TERMINALS WITH

THERMOSTAT REMOVED

(ANITICIPATOR, CLOCK, ETC.,

MUST BE OUT OF CIRCUIT.)

HOOK-AROUND

AMMETER

EXAMPLE: 5.0 AMPS ON AMMETER

10 TURNS AROUND JAWS

 

=  0.5 AMPS FOR THERMOSTAT

     ANTICIPATOR SETTING

FROM UNIT 24-V

CONTROL TERMINALS

Check Safety Controls

The flame sensor, gas valve, and pressure switch were all

checked in the Start

up procedure section as part of normal

operation.

1. Check Main Limit Switch 

This control shuts off combustion system and energizes

air

circulating blower motor, if furnace overheats. By

using this method to check limit control, it can be

established that limit is functioning properly and will

operate if there is a restricted return

air supply or motor

failure. If limit control does not function during this test,

cause must be determined and corrected.
a. Run furnace for at least 5 minutes.
b. Gradually block off return air with a piece of

cardboard or sheet metal until the limit trips.

c. Unblock return air to permit normal circulation.

d. Burners will re

light when furnace cools down.

2. Check Pressure Switch(es) 

This control proves operation of the draft inducer blower.
a. Turn off 115

v power to furnace.

b. Disconnect inducer motor lead wires from wire

harness.

c. Turn on 115

v power to furnace.

d. Set thermostat to “call for heat” and wait 1 minute.

When pressure switch is functioning properly, hot

surface igniter should 

NOT 

glow and control

diagnostic light flashes a status code 3. If hot surface

igniter glows when inducer motor is disconnected,

shut down furnace immediately.

e. Determine reason pressure switch did not function

properly and correct condition.

f. Turn off 115

v power to furnace.

g. Reconnect inducer motor wires, replace door, and

turn on 115

v power.

h. Blower will run for 90 seconds before beginning the

call for heat again.

i. Furnace should ignite normally.

Checklist

1. Put away tools and instruments. Clean up debris.
2. Verify that switches SW1

1 and SW1

6 are OFF

 

and

other setup switches are set as desired. Verify that

switches SW1

7 and SW1

8 for the blower OFF DELAY

are set as desired per 

Table 4

.

3. Verify that blower and control doors are properly

installed.

4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s

instructions.

6. Review Home Owner’s Information with owner.
7. Attach literature packet to furnace.

Summary of Contents for A3 Series

Page 1: ...tures or product labels The signal word WARNING is used throughout this manual in the following manner Safety alert symbol When you see this symbol on the unit and in instructions or manuals be alert...

Page 2: ...eath WARNING signifies hazards which could result in personal injury or death CAUTION is used to identify unsafe practices which may result in minor personal injury or product and property damage NOTE...

Page 3: ...in Connected Condensate Drain Trapped Manual Gas Shut off Upstream of Furnace Drip Leg Gas Valve turned ON Type of Gas Natural Propane Filter Type and Size Shade in Final Furnace Settings Below O N O...

Page 4: ...l Setup Switches SW1 The furnace control has 8 setup switches that may be set to meet the application requirements To set these setup switches for the appropriate requirement 1 Remove blower door 2 Lo...

Page 5: ...soap solution made specifically for the detection of leaks to check all connections A fire or explosion may result causing property damage personal injury or loss of life WARNING Adjustments FIRE HAZ...

Page 6: ...0 Btu cu ft Specific gravity 0 62 Therefore Orifice No 44 Furnace is shipped with No 44 orifices In this example all main burner orifices are the correct size and do not need to be changed to obtain p...

Page 7: ...ease input rate Figure 3 Redundant Automatic Gas Control Valve 2 Stage without Tower Pressure Ports ON OFF Switch Regulator Seal Cap RegulatorAdjustment Regulator Seal Cap under Cap 1 2 NPT Outlet 1 8...

Page 8: ...s warning could result in personal injury death and or property damage Manifold pressure tap set screw must be tightened or 1 8 in NPT pipe plug must be installed to prevent gas leaks WARNING c Tighte...

Page 9: ...300 21 171 343 857 62 58 116 290 22 164 327 818 64 56 112 281 23 157 313 783 66 54 109 273 24 150 300 750 68 53 106 265 25 144 288 720 70 51 103 257 26 138 277 692 72 50 100 250 27 133 267 667 74 48...

Page 10: ...43 3 8 1 6 42 3 2 1 4 850 44 3 8 1 6 43 3 5 1 5 43 3 6 1 5 43 3 7 1 6 875 44 3 6 1 5 44 3 7 1 6 43 3 4 1 4 43 3 5 1 5 4000 900 44 3 4 1 4 44 3 5 1 5 44 3 7 1 5 44 3 8 1 6 1219 925 44 3 2 1 4 44 3 4 1...

Page 11: ...re and airflow FURNACE DAMAGE HAZARD Failure to follow this caution may result in S Overheating the heat exchangers or condensing flue gases in heat exchanger areas not designed for condensate S Short...

Page 12: ...r off delay See Table 4 and Figure 4 Figure 5 Table 4 Blower Speed Taps DESIRED HEATING MODE BLOWER OFF DELAY SEC SETUP SWITCH SW1 7 and 8 POSITION 90 OFF OFF 120 ON OFF 150 OFF ON 180 ON ON Adjust Co...

Page 13: ...r refer to unit wiring diagram TWN 1 CFM 2 3 4 5 6 7 8 SW2 CF AC SW2 1 Twining OFF Allows for selection of furnace Main OFF or Secondary ON when Twinned furnace setup is required See kit instructions...

Page 14: ...this method to check limit control it can be established that limit is functioning properly and will operate if there is a restricted return air supply or motor failure If limit control does not funct...

Page 15: ...FF OFF ON 605 565 510 455 420 See note 4 OFF ON OFF 785 750 705 675 630 585 See note 4 OFF ON ON 955 920 895 860 825 785 755 720 685 650 ON OFF OFF 1135 1110 1080 1055 1020 990 935 880 825 745 ON OFF...

Page 16: ...0 22 Clg Default OFF OFF OFF 2010 1960 1910 1850 1800 1750 1690 1645 1565 1480 Cooling SW2 OFF OFF ON 1015 805 645 550 480 See note 4 OFF ON OFF 1075 975 915 835 765 See note 4 OFF ON ON 1205 1135 105...

Page 17: ...itioned air is discharged upward Since this furnace can be installed in any of the 4 positions shown in Figure 7 you must revise your orientation to component location accordingly Figure 7 Multipoise...

Page 18: ...isconnecting the limit switch To retrieve Status Codes follow the procedure below 2 Turn Setup Switch SW1 1 ON 3 Manually close blower door switch 4 Control will flash up to 7 Status Codes 5 The last...

Page 19: ...eason Service as necessary 4 Inspect burner compartment before each heating season for rust corrosion soot or excessive dust If necessary have furnace and burner serviced by a qualified service agency...

Page 20: ...balance will be affected 7 If greasy residue is present on blower wheel remove wheel from the blower housing and wash it with an appropriate degreaser To remove wheel a Mark blower wheel location on s...

Page 21: ...following items must be performed by a qualified service technician If the burners develop an accumulation of light dirt or dust they may be cleaned by using the following procedure NOTE Use a back up...

Page 22: ...the Hot Surface Igniter NOTE Use propane resistant pipe dope to prevent leaks Do not use Teflon tape 13 Install the gas pipe to the gas valve Figure 12 Igniter Position Side View L12F041 2 in 2 5 mm...

Page 23: ...quired Verify a condensate trap gasket is included in the service kit or obtain one from your local distributor 1 Disconnect power at external disconnect fuse or circuit breaker 2 Turn off gas at exte...

Page 24: ...wiring diagram and reconnect wires to flame rollout switch gas valve igniter and flame sensor 10 Turn on gas and electrical supplies to furnace 11 Check furnace operation through two complete heat op...

Page 25: ...uart of anti freeze solution into the funnel tube Antifreeze should run through the collector box overfill condensate trap and flow to an open drain 8 Replace the rubber plug in the port on the collec...

Page 26: ...SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace F G 9MVE Specifications subject to change without notice 440 04 4801 03 26 Figure 15 Service Label 340688 2 REV D...

Page 27: ...SERVICE AND TECHNICAL SUPPORT MANUAL Gas Furnace F G 9MVE Specifications subject to change without notice 27 440 04 4801 03 Figure 16 Wiring Diagram 340688 2 REV D...

Page 28: ...t flashes When done put setup switch SW1 1 in the OFF position Was there a previous status code other than the heartbeat Go to section below for the status code that was flashed Does the control respo...

Page 29: ...t check manifold pressure If OK check burner carryover and flame sensor location Clean flame sensor with fine steel wool and recheck current Nominal current is 4 0 to 6 0 microamps Is current near typ...

Page 30: ...t high speed and the high heat pressure switch relay HPSR is de energized to close the NC contact When sufficient pressure is available the high heat pressure switch HPS closes and the high heat gas v...

Page 31: ...tor BLWM will continue operating at cooling airflow for an additional 90 seconds Jumper Y Y2 to DHUM to reduce the cooling off delay to 5 seconds See Figure 4 b Two Stage Thermostat and Two Speed Cool...

Page 32: ...eat pump the furnace control automatically changes the timing sequence to avoid long blower off times during demand defrost cycles Whenever W W1 is energized along with Y1 or Y Y2 the furnace control...

Page 33: ...801 03 Figure 20 Variable Speed Furnace with Single Stage Heat Pump Dual Fuel L09F026 NOTE 9 Figure 21 Variable Speed Furnace with Two Stage Heat Pump Dual Fuel L09F028 NOTE 9 Figure 22 Variable Speed...

Page 34: ...stallation Instructions for additional information and setup procedure 4 When using a Humidity Sensing Thermostat set DEHUMIDIFY OPTIONS to H DE ENRGZD FOR DEHUM 5 Optional connection If wire is conne...

Page 35: ...ector box Condensate trap Condensate trap elbow Gaskets WARNING FIRE EXPLOSION ELECTRICAL SHOCK AND CARBON MONOXIDE POISONING HAZARD Failure to follow this warning could result in dangerous operation...

Page 36: ...ed X ECM S Single stage T Two stage FEATURE B Base AFUE Efficiency E Extra AFUE Efficiency C Communicating D Dual Certified 2 pipe or 1 pipe R 2 pipe only S Single stage T Two stage N Standard L Low N...

Reviews: