Lennox SL280DFV Installation and operation manual

Page 1
UNIT INFORMATIONUNIT INFORMATION
Service Literature
©2016 Lennox Industries, Inc.
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause property damage,
personal injury or loss of life. Installation and service
must be performed by a licensed professional HVAC
installer (or equivalent), service agency or the gas
supplier.
WARNING
Shock hazard. Disconnect power before
servicing. Integrated control is not eld
repairable. If control is inoperable, simply
replace entire control. Can cause injury
or death. Unsafe operation will resul if
repair is attempted.
SL280DFV series units are 80% e󰀩ciency gas furnaces
used for downow applications only, manufactured with
Lennox Duralok heat exchangers formed of aluminized
steel. Units are available in heating capacities of 66,000 to
110,000 Btuh and cooling applications up to 5 tons. Refer
to Engineering Handbook for proper sizing.
Units are factory equipped for use with natural gas. Kits
are available for conversion to LPG operation. SL280DFV
model units are equipped with a communicating enabled
SureLight ® two-stage variable speed integrated control.
All units use a redundant gas valve to assure safety shut-
o󰀨 as required by CSA.
All specications in this manual are subject to change.
Procedures outlined in this manual are presented as a
recommendation only and do not supersede or replace lo-
cal or state codes. In the absence of local or state codes,
the guidelines and procedures outlined in this manual (ex-
cept where noted) are recommendations only and do not
constitute code.
CAUTION
As with any mechanical equipment, contact with
sharp sheet metal edges can result in personal
injury. Take care while handling this equipment and
wear gloves and protective clothing.
TABLE OF CONTENTS
Specications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Parts Identication . . . . . . . . . . . . . . . . . . . . . . . . . Page 7
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . Page 8
II Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 36
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 36
IV Heating System Service Checks . . . . . . . . . Page 38
V Typical Operating Characteristics . . . . . . . . . Page 41
VI Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . Page 41
VII Wiring and Sequence of Operation . . . . . . Page 44
VIII Program Unit Capacity Size Mode . . . . . . Page 61
IX Field Wiring and Jumper Settings . . . . . . . . Page 47
X Troubleshooting Flow Chart . . . . . . . . . . . . . . Page 62
SL280DFV
Corp 1117-L4
Revised 03/2022
COMMUNICATING ENABLED SL280DFV SERIES UNITS

Page 2
SPECIFICATIONS
Gas
Heating
Performance
Model No. SL280DF070V36A SL280DF090V48B SL280DF090V60C SL280DF110V60C
1 AFUE 80% 80% 80% 80%
High
Fire
Input - Btuh 66,000 88,000 88,000 110,000
Output - Btuh 52,000 69,000 70,000 87,000
Temperature rise range - °F 35-65 35-65 35-65 35-65
Gas Manifold Pressure (in. w.g.)
Nat. Gas / LPG/Propane
3.5 / 10.0 3.5 / 10.0 3.5 / 10.0 3.5 / 10.0
Low
Fire
Input - Btuh 43,000 57,000 57,000 72,000
Output - Btuh 35,000 46,000 46,000 59,000
Temperature rise range - °F 25-55 25-55 25-55 25-55
Gas Manifold Pressure (in. w.g.)
Nat. Gas / LPG/Propane
1.7 / 4.5 1.7 / 4.5 1.7 / 4.5 1.7 / 4.5
High static - in. w.g. Heating 0.8 0.8 0.8 0.8
Cooling 1.0 1.0 1.0 1.0
Connections
in.
Flue connection - in. round 4 4 4 4
Gas pipe size IPS 1/2 1/2 1/2 1/2
Indoor
Blower
Wheel nominal diameter x width - in. 10 x 8 11 x 9 11 x 10 11 x 10
Motor output - hp 1/2 1 1 1
Tons of add-on cooling 2 - 3 3 - 4 3.5 - 5 3.5 - 5
Air Volume Range - cfm 589 - 1514 830 - 1996 899 - 2273 882 - 2120
Electrical
Data
Voltage 120 volts - 60 hertz - 1 phase
Blower motor full load amps 7.7 12.8 12.8 12.8
Maximum overcurrent protection 15 20 20 20
Shipping Data lbs. - 1 package 130 153 164 173
NOTE - Filters and provisions for mounting are not furnished and must be eld provided.
1 Annual Fuel Utilization E󰀩ciency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces.
OPTIONAL ACCESSORIES - ORDER SEPARATELY
NOTE - FURNACES CANNOT BE TWINNED!
“A” Width
Models
“B” Width
Models
“C” Width
Models
CABINET ACCESSORIES
Downow Combustible Flooring Base 11M59 11M60 11M61
CONTROLS
iComfort®S30 Ultra-Smart Wi-Fi Thermostat 19V30 19V30 19V30
2Remote Outdoor Air Temperature Sensor X2658 X2658 X2658
1Discharge Air Temperature Sensor 88K38 88K38 88K38
DOWNFLOW FILTER KITS
3 Downow Filter Cabinet 51W06 51W07 51W08
No. and Size of lter - in. (1) 20 x 20 x 1 (2) 16 x 20 x 1 (2) 16 x 20 x 1
NIGHT SERVICE KIT
Night Service Kit 16S36 16S36 16S36
1 Remote Outdoor Air Temperature Sensor is used with conventional (non-iComfort® Communicating) outdoor units (sensor is furnished with iComfort® Communicating
outdoor units). Allows the thermostat to display outdoor temperature. Required in dual-fuel and EDA applications.
2 Optional for service diagnostics.
3 Cleanable polyurethane, frame-type lter.

Page 3
BLOWER DATA
SL280DF070V36A BLOWER PERFORMANCE (less lter)
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range
HEATING
1Heating Speed
DIP Switch
Settings
First Stage Heating Speed - cfm Second Stage Heating Speed - cfm
+24% 1065 1170
+18% 1010 1115
+12% 960 1055
+6% 910 1000
Factory Default 860 945
–6% 805 885
–12% 755 830
–18% 705 775
COOLING
1Cooling Speed
DIP Switch
Settings
First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm
Low Medium-Low Medium-High 2High Low Medium-Low Medium-High 2High
[phone] 1015 1101 1241 1427
Factory Default 618 683 778 924 922 1014 1115 1304
–537 619 691 811 800 900 1024 1169
1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.
2 Factory default setting.
NOTES - The e󰀨ect of static pressure is included in air volumes shown.
First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28% and 38% of the selected second stage cooling speed - minimum 250 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 250 cfm.
SL280DF070V36A BLOWER MOTOR WATTS (COOLING)
1Cooling Speed
DIP Switch
Settings
Motor Watts @ Various External Static Pressures - in. wg.
First Stage Second Stage
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
+ Setting
Cooling
Speed
Low 44 62 74 90 103 119 133 148 166 119 144 166 189 212 231 242 267 278 298 323
Med-Low 46 63 83 96 115 128 144 170 181 138 162 177 212 229 247 270 288 320 342 363
Med-High 66 81 104 127 144 160 175 195 219 185 210 238 266 293 317 349 374 399 432 448
High 100 123 138 167 191 211 234 255 271 299 328 354 380 412 434 477 499 528 557 570
Factory Default
Cooling
Speed
Low 34 53 65 78 90 105 118 129 144 89 111 134 153 178 194 208 229 247 263 273
Med-Low 38 57 64 85 98 107 133 147 158 104 125 144 166 192 212 230 261 267 295 315
Med-High 49 72 87 96 122 135 160 176 197 141 167 184 216 237 256 288 304 326 356 383
High 70 90 109 132 158 172 201 222 231 218 245 276 306 323 357 374 403 444 472 489
– Setting
Cooling
Speed
Low 31 44 56 67 80 92 100 112 121 69 86 105 124 140 154 176 196 209 220 242
Med-Low 33 45 60 73 89 104 114 123 144 73 89 111 124 155 175 196 210 224 243 263
Med-High 40 54 74 86 106 115 134 142 170 108 118 153 170 196 219 227 253 266 286 316
High 52 74 85 107 128 149 161 181 201 156 181 208 222 253 284 305 333 356 374 398

Page 4
BLOWER DATA
SL280DF090V48B BLOWER PERFORMANCE (less lter)
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range
HEATING
1Heating Speed
DIP Switch
Settings
First Stage Heating Speed - cfm Second Stage Heating Speed - cfm
+24% 1360 1500
+18% 1285 1415
+12% 1220 1350
+6% 1135 1285
Factory Default 1075 1200
–6% 1030 1110
–12% 960 1050
–18% 890 975
COOLING
1Cooling Speed
DIP Switch
Settings
First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm
Low Medium-Low Medium-High 2High Low Medium-Low Medium-High 2High
[phone] 1085 1330 1545 1730
Factory Default 690 820 950 1110 990 1200 1400 1,595
–610 745 855 1005 895 1075 1270 1460
1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.
2 Factory default setting.
NOTES - The e󰀨ect of static pressure is included in air volumes shown.
First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28% and 38% of the selected second stage cooling speed - minimum 380 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 380 cfm.
SL280DF090V48B BLOWER MOTOR WATTS (COOLING)
1Cooling Speed
DIP Switch
Settings
Motor Watts @ Various External Static Pressures - in. wg.
First Stage Second Stage
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
+ Setting
Cooling
Speed
Low 33 59 77 98 122 142 166 192 214 97 129 150 188 217 247 267 302 323 365 394
Med-Low 64 91 118 139 167 193 215 246 272 156 188 230 269 313 346 377 429 452 491 529
Med-High 92 119 150 174 209 240 261 292 319 281 304 361 413 455 473 528 552 607 637 673
High 136 174 200 236 264 305 342 376 399 442 470 538 566 603 636 691 730 775 814 838
Factory Default
Cooling
Speed
Low 23 50 63 84 104 124 150 168 194 74 103 126 155 183 210 243 264 290 316 349
Med-Low 45 74 98 114 140 163 192 216 247 120 155 192 223 246 276 314 352 382 412 458
Med-High 62 93 122 143 173 195 232 260 290 206 236 285 324 369 401 437 483 514 551 590
High 112 142 168 202 220 253 282 306 346 323 336 400 445 489 523 558 595 643 660 689
– Setting
Cooling
Speed
Low 17 38 56 72 88 115 132 150 170 51 78 106 129 155 178 207 229 259 289 311
Med-Low 31 54 76 97 117 142 165 187 209 92 122 147 178 217 244 264 289 322 361 385
Med-High 51 76 104 125 153 175 202 222 258 135 177 208 233 272 311 349 386 417 452 491
High 78 107 137 155 184 215 246 268 301 247 282 313 365 398 445 483 521 558 582 620

Page 5
BLOWER DATA
SL280DF090V60C BLOWER PERFORMANCE (less lter)
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range
HEATING
1Heating Speed
DIP Switch
Settings
First Stage Heating Speed - cfm Second Stage Heating Speed - cfm
+24% 1540 1695
+18% 1465 1615
+12% 1390 1530
+6% 1320 1450
Factory Default 1245 1365
–6% 1170 1285
–12% 1095 1205
–18% 1020 1120
COOLING
1Cooling Speed
DIP Switch
Settings
First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm
Low Medium-Low Medium-High 2High Low Medium-Low Medium-High 2High
[phone] 1590 1585 1770 2000 2275
Factory Default 1020 1135 1285 1445 1420 1610 1845 2,050
–900 1005 1155 1280 1305 1395 1645 1875
1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.
2 Factory default setting.
NOTES - The e󰀨ect of static pressure is included in air volumes shown.
First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28% and 38% of the selected second stage cooling speed - minimum 450 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 450 cfm.
SL280DF090V60C BLOWER MOTOR WATTS (COOLING)
1Cooling Speed
DIP Switch
Settings
Motor Watts @ Various External Static Pressures - in. wg.
First Stage Second Stage
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
+ Setting
Cooling
Speed
Low 81 109 135 154 190 215 243 269 291 197 229 269 314 351 403 424 465 503 542 572
Med-Low 117 142 175 204 227 252 285 308 340 299 329 388 432 466 495 549 586 645 669 705
Med-High 143 183 208 247 283 312 352 385 423 451 501 521 587 633 664 705 765 794 848 879
High 209 246 291 329 370 402 447 490 525 689 720 783 826 890 938 995 1032 1072 1104 1131
Factory Default
Cooling
Speed
Low 63 92 114 139 162 186 216 242 270 144 183 217 248 286 307 354 386 421 459 498
Med-Low 82 111 141 159 195 223 247 274 308 211 245 294 331 369 401 445 486 523 559 604
Med-High 121 148 181 211 241 279 304 331 356 331 366 411 468 497 546 588 629 664 707 748
High 155 194 216 260 296 334 363 393 434 481 535 574 604 655 714 762 816 851 877 942
– Setting
Cooling
Speed
Low 53 76 101 121 139 166 184 209 238 117 149 180 203 235 269 294 327 349 387 421
Med-Low 68 94 120 137 166 193 219 239 266 154 187 219 258 291 319 365 386 424 458 492
Med-High 88 117 144 169 204 227 251 282 313 225 254 298 355 382 427 459 503 542 580 604
High 124 156 183 208 239 267 304 326 359 362 395 436 484 520 568 614 643 686 721 746

Page 6
BLOWER DATA
SL280DF110V60C BLOWER PERFORMANCE (less lter)
0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range
HEATING
1Heating Speed
DIP Switch
Settings
First Stage Heating Speed - cfm Second Stage Heating Speed - cfm
+24% 1645 1810
+18% 1565 1720
+12% 1485 1635
+6% 1405 1545
Factory Default 1325 1460
–6% 1245 1370
–12% 1170 1285
–18% 1090 1195
COOLING
1Cooling Speed
DIP Switch
Settings
First Stage Cooling Speed - cfm Second Stage Cooling Speed - cfm
Low Medium-Low Medium-High 2High Low Medium-Low Medium-High 2High
[phone] 1525 1500 1755 1915 2120
Factory Default 975 1115 1250 1400 1360 1585 1770 1960
–895 1005 1130 1245 1225 1405 1595 1760
1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specic DIP Switch Settings.
2 Factory default setting.
NOTES - The e󰀨ect of static pressure is included in air volumes shown.
First stage HEAT is approximately 91% of the same second stage HEAT.
First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position.
Continuous Fan Only speed is selectable at 28% and 38% of the selected second stage cooling speed - minimum 450 cfm.
Lennox iHarmony® Zoning System Applications - Minimum blower speed is 450 cfm.
SL280DF110V60C BLOWER MOTOR WATTS (COOLING)
1Cooling Speed
DIP Switch
Settings
Motor Watts @ Various External Static Pressures - in. wg.
First Stage Second Stage
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
+ Setting
Cooling
Speed
Low 78 101 128 144 172 200 218 244 264 172 196 243 284 321 360 391 428 452 494 528
Med-Low 108 135 162 192 213 241 269 295 324 268 294 352 376 424 466 505 554 581 604 645
Med-High 146 180 203 238 271 305 334 358 396 373 424 459 504 529 575 641 680 712 747 810
High 181 219 254 291 327 365 401 436 479 510 557 596 660 725 763 815 869 922 962 993
Factory Default
Cooling
Speed
Low 62 87 108 125 148 173 196 222 239 135 165 194 231 267 305 320 346 381 422 457
Med-Low 87 115 135 158 189 218 236 264 285 195 226 270 311 347 377 421 455 494 530 562
Med-High 114 140 173 201 224 250 283 312 339 290 335 358 401 450 497 528 565 611 640 677
High 148 186 207 246 282 307 354 375 410 395 438 484 525 559 608 659 711 745 776 826
– Setting
Cooling
Speed
Low 47 67 94 108 128 140 172 193 212 106 134 161 191 214 238 259 295 322 349 379
Med-Low 67 91 114 134 151 180 206 226 247 147 181 210 245 280 312 347 376 404 445 476
Med-High 94 116 141 167 198 210 242 259 288 207 236 284 320 356 391 421 473 494 535 573
High 118 146 176 202 222 248 285 313 337 280 315 356 398 444 478 520 559 607 627 669

Page 7
PARTS IDENTIFICATION
BLOWER ASSEMBLY
INTERNAL FLUE
PIPE ASSEMBLY
FLUE CHASE
GASKET
DOOR INTERLOCK SWITCH
HEAT EXCHANGER
COMBUSTION AIR INDUCER
COMBUSTION AIR INDUCER
PRESSURE SWITCHES
GAS VALVE
BURNER BOX ASSEMBLY
INNER BLOWER ACCESS PANEL
ACCESS PANEL
CONTROL BOX
(Includes two-stage integrated control,
transformer and circuit breaker)
ROLLOUT SWITCH
PRIMARY LIMIT LOCATION
SECONDARY LIMIT
FIGURE 1

Page 8
I-UNIT COMPONENTS
Unit components are shown in FIGURE 1. The gas valve,
combustion air inducer and burners can be accessed by
removing the access panel. Electrical components are in
the control box (FIGURE 2) found in the blower section.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can a󰀨ect
electronic components. Take precautions
to neutralize electrostatic charge by
touching your hand and tools to metal
prior to handling the control.
A- Control Box
1. Control Transformer (T1)
A transformer located in the control box provides power
to the low voltage section of the unit. Transformers on all
models are rated 40VA with a 120V primary and a 24V
secondary.
2. Door Interlock Switch (S51)
An interlock switch rated 14A at 125VAC is wired in series
with line voltage. When the indoor blower access panel is
removed the unit will shut down.
CONTROL BOX
SureLight
®
Integrated Control
Interlock Switch
Transformer
Circuit Breaker
FIGURE 2
3. Circuit Breaker (CB8)
A 24V circuit breaker is also located in the control box.
The switch provides overcurrent protection to the trans-
former (T1). The breaker is rated 3A at 32V. If the current
exceeds this limit the breaker will trip and all unit opera-
tion will shutdown. The breaker can be manually reset by
pressing the button on the face. See FIGURE 3.
CIRCUIT BREAKER CB8
PRESS TO RESET
FIGURE 3
WARNING
Shock hazard.
Disconnect power before servicing. Integrated
control is not eld repairable.
If control is inoperable, simply replace entire control.
Can cause injury or death. Unsafe operation will
result if repair is attempted.
4. SureLight Integrated Control (A92)
Units are equipped with the communicating enabled Sure-
Light ® two-stage, variable speed integrated control. This
control is used with the communicating thermostat as part
of a communicating comfort system. The control can also
operate with a non-communicating conventional single or
two-stage thermostat. The system consists of a ignition
/ blower control (FIGURE 4 103130-XX and FIGURE 5
107045-XX) with control pin designations in TABLE 1, TA-
BLE 2, TABLE 3 and ignitor (FIGURE 14). The control and
ignitor work in combination to ensure furnace ignition and
ignitor durability. The control provides gas ignition, safety
checks and indoor blower control with two-stage gas heat-
ing. The furnace combustion air inducer, gas valve and in-
door blower are controlled in response to various system
inputs such as thermostat signal, pressure and limit switch
signal and ame signal. The control features a seven-seg-
ment LED display, indicating furnace status (including in-
door blower) and error codes. See table 4 and table 5. The
LED ashes in single digits. For example using table 5
under LIMIT CODE, an “E” followed by “2” followed by “5”
followed by “0”, the limit switch circuit is open. The control
also has two unpowered (dry) 1/4” contacts for a humid-
ier and a 120 volt accessory terminal. Both rated at (1)
one amp each.
Electronic Ignition
At the beginning of the heat cycle the integrated control
monitors the rst stage and second stage combustion air
inducer prove switch. The control will not begin the heating
cycle if the rst stage prove switch is closed (by-passed).
Likewise the integrated control will not begin the second
stage heating cycle if the second stage prove switch is
closed, and will remain in rst stage heat. However, if the
second stage prove switch closes during the rst stage
heat pre-purge, the control will allow second stage heat.

Page 9
Once the rst stage prove switch is determined to be open,
the combustion air inducer is energized on low (rst stage)
heat speed. When the di󰀨erential in the prove switch is
great enough, the prove switch closes and a 15-second
pre-purge begins.
NOTE - During abnormal conditions such as low supply
voltage or low outdoor temperatures and the low re pres-
sure switch does not close, the combustion air inducer will
switch to high re. After a 15 second pre-purge the high
re pressure switch will close and the unit will begin op-
eration on high re. After 10 to 20 seconds of high re
operation the unit will switch to low re.
After the 15-second pre-purge period, the SureLight ig-
nitor warms up for 20 seconds after which the gas valve
opens for a 4-second trial for ignition. The ignitor energiz-
es during the trial until ame is sensed. If ignition is not
proved during the 4-second period, the control will try four
more times with an inter purge and warm-up time between
trials of 35 seconds.
After a total of ve trials for ignition (including the initial
trial), the control goes into Watchguard-Flame Failure
mode. After a 60-minute reset period, the control will begin
the ignition sequence again.
Two Stage Operation / Thermostat Selection DIP
Switch
The control can be utilized in two modes: SINGLE-STAGE
thermostat or TWO-STAGE thermostat. The thermostat
selection is made using a DIP switch and must be posi-
tioned for the particular application. DIP switch 1, labeled
T”STAT HEAT STAGE is factory-set in the OFF position for
use with a two-stage thermostat. Move the DIP switch to
ON for use with a single stage thermostat.
While in the single-stage thermostat mode, the burners
will always re on rst-stage heat. The combustion air in-
ducer will operate on low speed and indoor blower will
operate on low heat speed. The unit will switch to second
stage heat after a “recognition period”. DIP switch 2, la-
beled SECOND STAGE DELAY, is factory set in the OFF
position for a 7 minute recognition period. The switch can
be moved to the ON position for a 12 minute recognition
period, after which time the unit will switch to secondstage
heat.
While in the two-stage thermostat mode (two DIP switch
setting) the burners will re on rst-stage heat. The com-
bustion air inducer will operate on low speed and indoor
blower will operate on low heat speed. The unit will switch
to second-stage heat on call from the indoor thermostat.
If there is a simultaneous call for rst and second stage
heat, the unit will re an rst stage heat and switch to sec-
ond stage heat after 30 seconds of operation. See Se-
quence of Operation ow charts in the back of this manual
for more detail.
TABLE 1
SureLight®Control 5 Pin Terminal Designation
PIN# Function
1Ignitor
2Combustion Air Inducer High
Speed
3 Combustion Air Inducer Low
Speed
4 Combustuion Air Inducer
Neutral
5 Ignitor Neutral
TABLE 2
SureLight® Control 12 Pin Terminal Designation
PIN# Function
1Gas Valve High Fire
2Second Stage Prove Switch
3 Rollout In
4 Ground
5 24V Hot
6 Primary Limit In
7 Gas Valve Low Stage
8Gas Valve Common
9 24V Neutral
10 Ground
11 Rollout Switch Out
12 1st Stage Prove Switch
TABLE 3
SureLight®Control 6 Pin Terminal Designation
PIN# Function
1Data Input From Motor
2Common
3 Not Used
4 Data Output To Motor
5 5 Volt Bias Supply
6 Not Used

Page 10
IGNITION CONTROL 103130-XX
THERMOSTAT CONNECTIONS (TB1)
1/4” QUICK CONNECT TERMINALS
RS-BUS LINK (TB82, future use)
I+ = DATA HIGH CONNECTION
I - = DATA LOW CONNECTION
RS-BUS OUTDOOR (TB83)
R = 24VAC
I + = DATA HIGH CONNECTION
I - = DATA LOW CONNECTION
C = 24VAXC COMMON
RS-BUS INDOOR (TB84)
R = 24VAC
I + = DATA HIGH CONNECTION
I - = DATA LOW CONNECTION
C = 24VAXC COMMON
FLAME SENSE
DIP SWITCHES
OUTDOOR AIR
SENSOR
TERMINALS
DISCHARGE AIR
SENSOR
TERMINALS
INDOOR
BLOWER
CONNECTOR
NEUTRAL
DIAGNOSTIC
PUSH BUTTON
TB83
COMMUNICATING
OUTDOOR
EQUIPMENT
TB84
COMMUNICATING
INDOOR
THERMOSTAT
DS = DEHUMIDIFICATION SIGNAL
W2 = HEAT DEMAND FROM 2ND STAGE T/STAT
W1 = HEAT DEMAND FROM 1ST STAGE T/STAT
R = CLASS 2 VOLTAGE TO THERMOSTAT
G = MANUAL FAN FROM T'STAT
C = THERMOSTAT SIGNAL GROUND CONNECTED TO
TRANSFORMER GRD (TR) & CHASIS GROUND (GRD)
Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL
Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL
O = THERMOSTAT SIGNAL TO HEAT PUMP
REVERSING VALVE
L = USE ONLY WITH A COMMUNICATING THERMOSTAT
AND A NON-COMMUNICATING OUTDOOR UNIT
DH = DEHUMIDIFICATION OUTPUT COMMUNICATING
THERMOSTAT ONLY
HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS
XMFR = 120 VAC OUTPUT TO TRANSFORMER
LI = 120 VAC INPUT TO CONTROL
ACC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY
NEUTRALS = 120 VAC NEUTRAL
W915 Y1 TO Y2
2 STAGE COMPR
W951 R TO O
HEAT PUMP
W914 R TO DS
DEHUM OR
HARMONY
W1 W2 G Y2 Y1 CCRDHL ODS
RI +I- CRI +I- C
7 SEGMENT LED
ACC
LINE 1
HUM
12 PIN LOW
VOLTAGE
CONNECTOR
NON-COMMUNICATINGNG
24V TERMINALS
HS/ CAI
FIGURE 4