background image

Specifications are subject to change without notice.

41

441 01 6100 02

maintenance to the accessories as recommended in the ac-

cessory instructions.

CLEANING AND/OR REPLACING AIR FILTER

The air filter arrangement will vary depending on the application.

The filter is exterior to the furnace casing.

NOTE

:  If the filter has an airflow direction arrow, the arrow

must point towards the blower.

Table 14 – Filter Size Information (In. / mm)

FURNACE

CASING

WIDTH

In. (mm)

FILTER SIZE (In. / mm)

FILTER TYPE

Side Return

Bottom Return

14-1/2

(368)

16 x 25 x 3/4

(406 x 635 x 19)

14 x 25 x 3/4

(356 x 635 x 19)

Washable*

17-1/2

(445)

16 X 25 X 3/4

(406 x 635 x 19)

16 X 25 X 3/4

(406 x 635 x 19)

Washable*

21 (533)

16 x 25 x 3/4

(406 x 635 x 19)

20 X 25 X 3/4

(508 x 635 x 19)

Washable*

24 (610)

16 x 25 x 3/4

(406 x 635 x 19)

24 X 25 X 3/4

(610 x 635 x 19)

Washable*

* Recommended

BLOWER MOTOR AND WHEEL

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury

or death.
Blower access door switch opens 115

v power to control.

No component operation can occur unless switch is closed.

Caution must be taken when manually closing this switch

for service purposes.

!

WARNING

NOTE

:  The blower wheel should not be dropped or bent as

balance will be affected. The following steps should be performed
by a qualified service agency.
To ensure long life and high efficiency, clean accumulated dirt

and grease from blower wheel and motor annually.
The inducer and blower motors are pre

lubricated and require no

additional lubrication. These motors can be identified by the

absence of oil ports on each end of the motor.
Clean blower motor and wheel as follows:

1. Turn off electrical supply to furnace.
2. Remove outer door.
3. For downflow or horizontal furnaces having vent pipes

within the furnace that pass in front of the blower access

door:

a. Disconnect vent connector from furnace vent elbow.

b. Disconnect and remove short piece of vent pipe from

within furnace.

4. Remove two screws from blower access door and remove

blower access door.

5. All factory wires can be left connected, but field thermo-

stat connections may need to be disconnected depending

on their length and routing.

6. Remove two screws holding blower assembly to blower

deck and slide blower assembly out of furnace.

7. Clean blower wheel and motor using a vacuum with soft

brush attachment. Blower wheel blades may be cleaned

with a small paint or flux brush. Do not remove or disturb

balance weights (clips) on blower wheel blades.

8. Vacuum any loose dust from blower housing, wheel and

motor.

9. If a greasy residue is present on blower wheel, remove

wheel from the blower housing and wash it with an appro-

priate degreaser. To remove wheel:

NOTE

:  Before disassembly, mark blower motor, and blower

housing so motor and each arm is positioned at the same location
during reassembly.

a. Disconnect power choke wires (if used)  and ground wire

attached to blower housing.

b. Remove screws securing cutoff plate and remove cutoff

plate from housing.

c. Loosen set screw holding blower wheel on motor shaft

(160+/

20 in.

lb. when reassembling).

d. Remove bolts holding motor to blower housing and slide

motor out of wheel (40+/

10 in.

lb. when reassembling).

e. Remove blower wheel from housing.

f. Clean wheel and housing.

10. Reassemble motor and blower by reversing steps 9f

through 11a, finishing with 9a. Be sure to reattach ground

wire to the blower housing.

11. Verify that blower wheel is centered in blower housing

and set screw contacts the flat portion of the motor shaft.

Loosen set screw on blower wheel and reposition if neces-

sary.

12. Spin the blower wheel by hand to verify that the wheel

does not rub on the housing.

13. Reinstall blower assembly in furnace.
14. Reinstall two screws securing blower assembly to blower

deck.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in shortened heat

exchanger life.
Heating fan speed(s) MUST be adjusted to provide proper

air temperature rise as specified on the rating plate.

Recommended operation is at the midpoint of the rise range

or slightly above. Refer to “SET TEMPERATURE RISE”

under START

UP, ADJUSTMENT, and SAFETY

CHECK.

CAUTION

!

NOTE

:   Refer to Table 5 for motor speed lead relocation if leads

were not identified before disconnection.

15. Refer to furnace

 

wiring diagram, and connect thermostat

leads if previously

 

disconnected.

16. To check blower for proper rotation:

a. Turn on electrical supply.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal

injury, or death.
Blower access door switch opens 115

v power to

furnace control. No component operation can occur

unless switch is closed. Exercise caution to avoid

electrical shock from exposed electrical components

when manually closing this switch for service purposes.

!

WARNING

b. Manually close blower access door switch.

NOTE

:  If thermostat terminals are jumpered at the time blower

access door switch is closed, blower will run for 90 sec before
beginning a heating or cooling cycle.

Summary of Contents for R8MXL

Page 1: ...FETY CHECK 30 General 30 Start up Procedures 30 Adjustments 30 Check Safety Controls 32 Checklist 33 SERVICE AND MAINTENANCE PROCEDURES 39 Introduction 39 Electrical Controls and Wiring 39 Care and Ma...

Page 2: ...a location and position as spe cified in the Location section of these instructions 3 Provide adequate combustion and ventilation air to the furnace space as specified in Air for Combustion and Ventil...

Page 3: ...140 3 8 7 16 8 7 16 213 5 213 5 FRONT OF CASING FRONT OF CASING TOP OF CASING TOP OF CASING 6 1 6 1 155 7 155 7 2 1 16 2 1 16 51 6 51 6 5 1 5 1 130 5 130 5 1 7 1 7 43 5 43 5 7 8 7 8 22 2 22 2 ACCESSOR...

Page 4: ...Specifications are subject to change without notice 4 441 01 6100 02 A10269 Fig 2 Clearances to Combustibles...

Page 5: ...DISCHARGE ESD PRECAUTIONS PROCEDURE FURNACE RELIABILITY HAZARD Improper installation or service of furnace may cause premature furnace component failure Electrostatic discharge can affect electronic c...

Page 6: ...XIDE POISONING HAZARD Failure to follow this warning could result in personal injury or death and unit component damage Corrosive or contaminated air may cause failure of parts containing flue gas whi...

Page 7: ...also prevents the entrainment of drywall dust into combustion air which can cause fouling and plugging of furnace components The temperature of the return air to the furnace is maintained between 55_F...

Page 8: ...pped with means to prevent operation of either unit unless the damper is in the full heat or full cool position AIR FOR COMBUSTION AND VENTILATION Provisions for adequate combustion ventilation and di...

Page 9: ...IDE POISONING HAZARD Failure to follow this warning could result in death and or personal injury Many homes require air to be supplied from outdoors for furnace combustion ventilation and dilution of...

Page 10: ...lectrical and gas lines etc Combination of Indoor and Outdoor Air 1 Indoor openings shall comply with the Indoor Combus tion Air Method below and 2 Outdoor openings shall be located as required in the...

Page 11: ...as shown in Fig 13 NOTE It is required that the perforated supply air duct flanges be completely folded over or removed from furnace when installing the furnace on a factory supplied cased coil or co...

Page 12: ...red 15 7 8 403 19 483 16 1 2 419 19 5 8 498 Downflow Applications on Combustible Flooring subbase required 15 1 8 384 19 483 16 3 4 425 20 5 8 600 Downflow Applications on Combustible Flooring Coil wi...

Page 13: ...r Inlet These furnaces are shipped with bottom closure panel installed in bottom return air opening This panel MUST be in place when side return air inlet s is used without a bottom return air inlet N...

Page 14: ...pply air outlet on furnace Bend flange inward past 90_ with wide duct pliers See Fig 14 The supply air duct must be connected to ONLY the furnace supply outlet or air conditioning coil casing when use...

Page 15: ...IN BOTTOM A10131 Fig 16 Horizontal Suspension with Straps 30 IN 762mm MIN WORK AREA 6 MIN TYPE B VENT 17 3 4 22 SHEET METAL SEDIMENT TRAP EQUIPMENT MANUAL SHUT OFF GAS VALVE LINE CONTACT ONLY PERMISS...

Page 16: ...shall be installed at the furnace gas control valve and extend a minimum of 2 in 51 mm outside the furnace WARNING Gas piping must be installed in accordance with national and local codes Refer to cu...

Page 17: ...Yellow 3 1425 1380 1335 1290 1235 1185 1125 1075 1020 940 Orange 2 1260 1210 1160 1105 1050 990 935 880 820 755 Red 1 3 1095 1040 980 905 845 780 720 650 585 520 0902120 Gray 5 2180 2130 2080 2030 19...

Page 18: ...nal plumbing and gas codes before the furnace has been connected After all connections have been made purge lines and check for leakage at furnace prior to operating furnace If pressure exceeds 0 5 ps...

Page 19: ...change without notice 19 441 01 6100 02 A02163 Fig 20 Downflow Return Air Configurations and Restrictions A02162 Fig 21 Horizontal Return Air Configurations and Restrictions 2 51mm Street Elbow A0855...

Page 20: ...ZARD Failure to follow this warning could result in personal injury death or property damage The cabinet MUST have an uninterrupted or unbroken ground according to current edition of NEC NFPA 70 or lo...

Page 21: ...7 Refer to power cord manufacturer s listings 1 Remove cover from J Box 2 Route listed power cord through 7 8 in 22 mm diameter hole in J Box 3 Secure power cord to J Box bracket with a strain relief...

Page 22: ...24 V WIRING FIELD 115 208 230 460 V WIRING FACTORY 24 V WIRING FACTORY 115 V WIRING 208 230 OR 460 V THREE PHASE 208 230 V SINGLE PHASE BLOWER DOOR SWITCH WHT BLK WHT BLK NOTES Connect Y terminal in...

Page 23: ...proper vent sizing and installation requirements including local building codes the current edition of National Fuel Gas Code ANSI Z223 1 NFPA 54 NFGC Parts 12 and 13 the local building codes and furn...

Page 24: ...e between the chimney and the metal liner Exterior Masonry Chimney FAN NAT Installations with Type B Double Wall Vent Connectors NFPA AGA Table 8 Combined Appliance Maximum Input Rating in Thousands o...

Page 25: ...bris in cleanout Mortar tile metal vent fuel oil residue Is liner and top seal in good condition Is chimney property lined with clay tile liner Crown condition Missing mortar or brick Rebuild crown Ye...

Page 26: ...ews The factory supplied vent elbow does NOT count as part of the number of vent connector elbows The vent connector can exit the furnace through one of 5 locations on the casing 1 Attach the single w...

Page 27: ...2 Horizontal Left Vent elbow right Fig 35 132 000 5 127 7 2 NOTE All vent configurations must also meet National Fuel Gas Code venting requirements NFGC 4 in 102 mm inside casing or vent guard Includi...

Page 28: ...Left then Up SEE NOTES 1 2 3 4 5 7 8 9 on the page following these figures A03212 Fig 32 Downflow Application Vent Elbow Up then Right SEE NOTES 1 2 4 7 8 9 on the page following these figures A03213...

Page 29: ...and downflow installations must use Type B vent immediately after exiting the furnace except when factory authorized Downflow Vent Guard Kit is used in the downflow position See Specification Sheet fo...

Page 30: ...alve and humidifier will not be turned on See Fig 24 ELECTRICAL SHOCK HAZARD Failure to follow this warning could result in personal injury or death Blower access door switch opens 115 v power to cont...

Page 31: ...d Turn gas valve ON OFF switch to ON e Manually close blower door switch f Set thermostat to call for heat g Remove regulator seal cap and turn regulator adjusting screw counterclockwise out to decrea...

Page 32: ...the wires normally connected to thermostat sub base terminals R and W The thermostat anticipator should NOT be in the circuit while measuring current 1 Remove thermostat from subbase or from wall 2 C...

Page 33: ...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 fun...

Page 34: ...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 97 243 28 129 257 643 76 4...

Page 35: ...Specifications are subject to change without notice 35 441 01 6100 02 Table 12 Orifice Size and Manifold Pressure In W C for Gas Input Rate A10180...

Page 36: ...Specifications are subject to change without notice 36 441 01 6100 02 Table 12 Orifice Size and Manifold Pressure In W C for Gas Input Rate CONT A10180A...

Page 37: ...Specifications are subject to change without notice 37 441 01 6100 02 Table 13 Orifice Size And Manifold Pressure In W C For Gas Input Rate A10181...

Page 38: ...Specifications are subject to change without notice 38 441 01 6100 02 Table 13 Orifice Size And Manifold Pressure In W C For Gas Input Rate CONT A10181A...

Page 39: ...itch with a suitable warning label WARNING The electrical ground and polarity for 115 v wiring must be properly maintained Refer to Fig 25 for field wiring information and to Fig 47 for furnace wiring...

Page 40: ...ons on the label attached to the furnace WARNING CARBON MONOXIDE POISONING AND FIRE HAZARD Failure to follow this warning could result in personal injury death and or property damage Never operate uni...

Page 41: ...a small paint or flux brush Do not remove or disturb balance weights clips on blower wheel blades 8 Vacuum any loose dust from blower housing wheel and motor 9 If a greasy residue is present on blowe...

Page 42: ...on necting wires from switches because damage may occur a Draft safeguard switch b Inducer motor c Pressure switch es d Limit over temperature switch e Gas valve f Hot surface igniter g Flame sensing...

Page 43: ...agram follow the sequence of operation through the different modes Read and follow the wiring diagram very carefully NOTE If a power interruption occurs during a call for heat W the control will start...

Page 44: ...lay to 5 sec See Fig 24 3 Continuous Blower Mode When the R to G circuit is closed by the thermostat the blower motor BLWM will operate on continuous blower speed same as HEAT speed Terminal EAC 1 is...

Page 45: ...Specifications are subject to change without notice 45 441 01 6100 02 A150040 Fig 47 Wiring Diagram...

Page 46: ...the control will go through a brief component test sequence The inducer will start and run for the entire component test The HSI blower motor FAN speed AMBER LED boards only HEAT speed and COOL speed...

Page 47: ...tor Inadequate combustion air supply flame rollout switch open Restricted vent Proper vent sizing Excessive wind 34 IGNITION PROVING FAILURE If flame is not sensed during the trial for ignition period...

Page 48: ...T Two stage TYPE N Standard L Low Nox FEATURE 045 45 000 BTU hr 070 70 000 BTU hr 090 90 000 BTU hr 110 110 000 BTU hr 135 135 000 BTU hr HEAT INPUT 14 143 16 17 171 2 21 21 24 241 2 CABINET WIDTH 08...

Reviews: