background image

SERVICE AND TECHNICAL SUPPORT MANUAL

Gas Furnace: (F/G)9MVE

Specifications  subject to change without notice.

440 04 4801 03

17

SERVICE AND MAINTENANCE

PROCEDURES

Untrained personnel can perform basic maintenance functions

such as cleaning and replacing air filters. All other operations

must be performed by trained service personnel. A qualified

service person should inspect the furnace once a year.

FIRE, INJURY OR DEATH HAZARD

Failure to follow this warning could result in personal

injury, death and/or property damage.
The ability to properly perform maintenance on this

equipment requires certain knowledge, mechanical

skills, tools, and equipment. If you do not possess

these, do not attempt to perform any service and

maintenance on this equipment other than those

procedures recommended in the Owner’s Manual.

!

WARNING

ENVIRONMENTAL  HAZARD

Failure to follow this caution may result in

environmental pollution.
Remove and recycle all components or materials (i.e.

oil, refrigerant, control board, etc.) before unit final

disposal.

CAUTION

!

ELECTRICAL SHOCK, FIRE OR EXPLOSION

HAZARD

Failure to follow this warning could result in personal

injury or death, or property damage.
Before installing, modifying, or servicing system, main

electrical disconnect switch must be in the OFF

position and install a lockout tag.  There may be more

than one disconnect switch.  Lock out and tag switch

with a suitable warning label.  Verify proper operation

after servicing. Always reinstall access doors after

completing service and maintenance.

!

WARNING

ELECTRICAL OPERATION HAZARD

Failure to follow this caution may result in improper

furnace operation or failure of furnace.
Label all wires prior to disconnection when servicing

controls. Wiring errors can cause improper and

dangerous operation.

CAUTION

!

General

These instructions are written as if the furnace is installed in an

upflow application. An upflow furnace application is where the

blower is located below the combustion and controls section of

the furnace, and conditioned 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 Orientations

A93041

Electrical Controls and Wiring

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal

injury or death.
There may be more than one electrical supply to the

furnace. Check accessories and cooling unit for additional

electrical supplies that must be shut off during furnace

servicing.  Lock out and tag switch with a suitable warning

label.

!

WARNING

The electrical ground and polarity for 115

v wiring must be

properly maintained. Refer to 

Figure 8

 for field wiring

information and to 

Figure 16

 for furnace wiring information.

NOTE

:  If the polarity is not correct, the STATUS LED on the

control will flash code 10 and prevent the furnace from heating.
The control system also requires an earth ground for proper
operation of the control and flame

sensing electrode.

The 24

v circuit contains an automotive

type, 3

amp. fuse

located on the control. (See 

Figure 4

) Any shorts of the 24

v

wiring during installation, service, or maintenance will cause

this fuse to blow. If fuse replacement is required, use ONLY a

3

amp. fuse. The control LED display will be off when fuse

needs to be replaced.

Troubleshooting

Refer to the service label. (See 

Figure 15

—Service Label)

The Troubleshooting Guide 

 Flow Chart (See 

Figure 17

) can

be a useful tool in isolating furnace operation problems.

Beginning with the word “Start,” answer each question and

follow the appropriate arrow to the next item.
The Guide 

 Flow Chart will help to identify the problem or

failed component. After replacing any component, verify correct

operation sequence.
Proper instrumentation is required to service electrical controls.

The control in this furnace is equipped with a Status Code LED

(Light

Emitting  Diode) to aid in installation, servicing, and

troubleshooting. Status codes can be viewed at the indicator in

blower door. The amber furnace control LED is either a

heartbeat, off or a code composed of 1 or 2 digits. The first digit

is the number of short flashes, the second digit is the number of

long flashes.

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: