Lennox SL280UHNV, SL280UH060NV36A, SL280UH080NV48B Series Manual

UNIT INFORMATION

Corp 1601-L8

Service Literature

ICOMFORT®-ENABLED SL280UHNV SERIES UNITS

SL280UHNVseries units are 80% efﬁ ciency gas furnac- es used for upﬂ ow or horizontal applications only, man- ufactured with Lennox Duralok heat exchangers formed of aluminized steel. SL280UHNV units are available in heating capacities of 40,000 to 100,000 Btuh and cooling applications up to 5 tons. Refer to Engineering Handbook for proper sizing.

Units are approved for installations up 4500 ft and factory equipped for use with natural gas only. SL280UHNV model units are equipped with the iComfort® enabled SureLight® two-stage variable speed integrated control. SL280UHNV unit meets the California Nitrogen Oxides (NOx) Standards and California Seasonal Efﬁ ciency re- quirements. All units use a redundant gas valve to assure safety shut-off as required by C.S.A.

All speciﬁ 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 local or state codes. In the absence of local or state codes, the guidelines and procedures outlined in this manual (except where noted) are recommendations only and do not constitute code.

SL280UHNV

Contents

I-Unit Components..........................................................4

Blower Data ..................................................................16

II-Placement and Installation ........................................ 31

III-Start-Up .................................................................... 31

IV-Heating System Service Checks ..............................32

V-Typical Operating Characteristics .............................34

VI-Maintenance ............................................................35

VII- Wiring and Sequence of Operation ........................38

VIII- Field Wiring With Conventional Thermostat ..........42

IX- Program Unit Capacity Size Modes ........................46

X- Troubleshooting ....................................................... 47

Page 1

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.

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.

SPECIFICATIONS

Gas Heating Performance

High Fire

Temperature rise range - °F 30 - 60 30 - 60

Gas Manifold Pressure (in. w.g.)

Low Fire

Temperature rise range - °F 20 - 50 20 - 50

Gas Manifold Pressure (in. w.g.)

High static - in. w.g. Heating 0.8 0.8

Connections

Flue connection − in. round 4 4

in.

Indoor

Wheel nominal diameter x width - in. 10 X 8 11-1/2 X 9

Blower

Tons of add-on cooling 2 - 3 2.5 - 4

Air Volume Range - cfm 606 - 1345 679 - 2002

Electrical Data Voltage 120 volts - 60 hertz - 1 phase

Blower motor full load amps 7.7 12.8

Maximum overcurrent protection 15 20

Shipping Data lbs. - 1 package 112 138

NOTE - Filters and provisions for mounting are not furnished and must be ﬁ eld provided.

Annual Fuel Utilization Efﬁ ciency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized

furnaces.

Model No. SL280UH060NV36A SL280UH080NV48B

AFUE 80% 80%

Input - Btuh 60,000 80,000

Output - Btuh 48,000 64,000

3.4 3.4

Natural Gas Only

Input - Btuh 39,000 52,000

Output - Btuh 31,000 41,000

1.5 1.5

Natural Gas Only

Cooling 1.0 1.0

Gas pipe size IPS 1/2 1/2

Motor output - hp 1/2 1.0

SPECIFICATIONS

Gas Heating Performance

High Fire

Temperature rise range - °F 30 - 60 30 - 60

Gas Manifold Pressure (in. w.g.)

Low Fire

Temperature rise range - °F 20 - 50 25 - 50

Gas Manifold Pressure (in. w.g.)

High static - in. w.g. Heating 0.8 0.8

Connections

Flue connection − in. round 4 4

in.

Indoor

Wheel nominal diameter x width - in. 11-1/2 X 10 11-1/2 X 10

Blower

Tons of add-on cooling 3 - 5 3 - 5

Air Volume Range - cfm 826 - 2305 812 - 2125

Electrical Data Voltage 120 volts - 60 hertz - 1 phase

Blower motor full load amps 12.8 12.8

Maximum overcurrent protection 20 20

Shipping Data lbs. - 1 package 157 161

NOTE - Filters and provisions for mounting are not furnished and must be ﬁ eld provided.

Annual Fuel Utilization Efﬁ ciency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized

furnaces.

Model No. SL280UH080NV60C SL280UH100NV60C

AFUE 80% 80%

Input - Btuh 80,000 100,000

Output - Btuh 64,000 80,000

3.4 3.4

Natural Gas Only

Input - Btuh 52,000 65,000

Output - Btuh 41,000 52,000

1.5 1.5

Natural Gas Only

Cooling 1.0 1.0

Gas pipe size IPS 1/2 1/2

Motor output - hp 1.0 1.0

Page 2

Combustion Air Inducer

Gas Valve

Air Intake Pipe

Heat Exchanger

ccess Panel

Inner Access

Panel

(includes two-stage integrated control,

transformer and circuit breaker)

FIGURE 1

Control Box

Blower Assembly

Page 3

I-Unit Components

SL280UHNV 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.

SL280UHNV units are factory equipped with a bottom return air panel in place. The panel is designed to be ﬁ eld removed as required for bottom air return. Markings are provided for side return air and may be cut out in the ﬁ eld.

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

CAUTION

Electrostatic discharge can affect electronic components. Take precautions during furnace installation and service to protect the furnace’s electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the furnace, the control and the technician at the same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an unpainted unit surface, such as the gas valve or blower deck, before performing any service procedure.

A- Control Box

1. Control Transformer (T1)

A transformer located in the control box provides power tothe low voltage section of the unit. Transformers on allmodels are rated 40VA with a 120V primary and a 24V

secondary.

2. Door Interlock Switch (S51)

A door interlock switch rated 14A at 125VAC is wired in series with line voltage. When the inner blower access panel

is removed the unit will shut down.

CONTROL BOX

Transformer

Circuit Breaker

Interlock Switch

SureLight

FIGURE 2

3. Circuit Breaker (CB8)

A 24V circuit breaker is also located in the control box. The switch provides overcurrent protection to the transformer (T1). The breaker is rated 3A at 32V. If the current exceeds this limit the breaker will trip and all unit operation will shutdown. The breaker can be manually reset by pressing the button on the face. See Figure 3

Integrated Control

CIRCUIT BREAKER CB8

PRESS TO RESET

FIGURE 3

WARNING

Shock hazard. Disconnect power before servicing. Integrated control is not ﬁ eld repairable. If control is inoperable, simply replace entire control. Can cause injury or death. Unsafe operation will resul if repair is attempted.

4. Integrated Control (A92)

Units are equipped with the icomfort enabled SureLight ® two-stage, variable speed integrated control. This control is used with the icomfort Wi-Fi® 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 and Figure 5) with control pin designations in Table 1, Table 2 and Table 3 and ignitor (Figure 13). 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 heating.

The furnace combustion air inducer, gas valve and indoor blower are controlled in response to various system inputs such as thermostat signal, pressure and limit switch signal and ﬂ ame signal. The control features a seven-segment LED display, indicating furnace status (including indoor blower) and error codes. The LED ﬂ ashes in single dig- its. 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 humidiﬁ er and a 120 volt accesso- ry terminal. Both rated at (1) one amp each.

Electronic Ignition

At the beginning of the heat cycle the integrated control monitors the ﬁ rst stage and second stage combustion air inducer prove switch. The control will not begin the heating cycle if the ﬁ 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 ﬁ rst stage heat. However, if the second stage prove switch closes during the ﬁ rst stage heat pre-purge, the control will allow second stage heat.

Once the ﬁ rst stage prove switch is determined to be open, the combustion air inducer is energized on low (ﬁ rst stage) heat speed. When the differential in the prove switch is great enough, the prove switch closes and a 15-second pre-purge begins.

Page 4

NOTE - During abnormal conditions such as low supply voltage or low outdoor temperatures and the low ﬁ re pres- sure switch does not close, the combustion air inducer will switch to high ﬁ re. After a 15 second pre-purge the high ﬁ re pressure switch will close and the unit will begin operation on high ﬁ re. After 10 to 20 seconds of high ﬁ re operation the unit will switch to low ﬁ re.

After the 15-second pre-purge period, the SureLight ignitor warms up for 20 seconds after which the gas valve opens for a 4-second trial for ignition. The ignitor energizes during the trial until ﬂ 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 ﬁ 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 positioned 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 ﬁ re on ﬁ 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, labeled 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 ﬁ re on ﬁ 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 ﬁ rst and second stage heat, the unit will ﬁ re an ﬁ rst stage heat and switch to sec- ond stage heat after 30 seconds of operation. See Sequence of Operation ﬂ ow charts in the back of this manual for more detail.

TABLE 1

SureLight® Control 5 Pin Terminal Designation

PIN# Function

1 Ignitor

2 Combustion 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

1 Gas Valve High Fire

2 Second Stage Prove Switch

3 Rollout In

4 Ground

5 24V Hot

6 Primary Limit In

7 Gas Valve Low Stage

8 Gas 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

1 Data Input From Motor

2 Common

3 Not Used

4 Data Output To Motor

5 5 Volt Bias Supply

Not Used

Page 5

HUM

LINE 1

7 SEGMENT LED

FLAME SENSE

DIAGNOSTIC

PUSH BUTTON

DIP SWITCHES

ACC

HS/ CAI

INDOOR

BLOWER

CONNECTOR

NEUTRAL

OUTDOOR AIR

SENSOR

TERMINALS

DISCHARGE AIR

SENSOR

TERMINALS

TB83

COMMUNICATING

OUTDOOR

EQUIPMENT

I + I -CRI + I -

TB84

COMMUNICATING

INDOOR

THERMOSTAT

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

1/4” QUICK CONNECT TERMINALS

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

W1 W2 GY2Y1

NON-COMMUNICATINGNG

24V TERMINALS

12 PIN LOW

VOLTAGE

CONNECTOR

W915 Y1 TO Y2

2 STAGE COMPR

W951 R TO O HEAT PUMP

W914 R TO DS

DEHUM OR

RDHLODS

HARMONY

THERMOSTAT CONNECTIONS (TB1)

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

DH = DEHUMIDIFICATION OUTPUT COMMUNICATING

L = USE ONLY WITH A COMMUNICATING THERMOSTAT

AND A NON-COMMUNICATING OUTDOOR UNIT

REVERSING VALVE

THERMOSTAT ONLY

FIGURE 4

Page 6

THERMOSTAT SELECTION

TWO STAGE

THERMOSTAT

1−STAGE

THERMOSTAT

(TIMED STAGING)

−SEE SW #2

HEATING BLOWER−OFF DELAY

90 SECOND

HTG BLOWER

OFF DELAY

60 SECOND

HTG BLOWER

OFF DELAY

120 SECOND

HTG BLOWER

OFF DELAY

180 SECOND

HTG BLOWER

OFF DELAY

−BLOWER ON DELAY − 30 SEC. FIXED

HEATING MODE BLOWER SPEED

+ 24%

+ 18%

+ 12%

INCREASE AIR HTG CFM

+ 6%

FACTORY

DEFAULT

− 6%

− 12%

DECREASE AIR HTG CFM

− 18%

INTEGRATED CONTROL CONFIGURATION GUIDE

2ND STAGE HEAT ON DELAY

7 MIN

DELAY

12 MIN

DELAY

FLAME SENSE

123456

S4S3

911

OUTDOOR

SENSOR

DISCHARGE

AIR SENSOR

I+ I

DIAGNOSTIC

PUSH BUTTON

UPSTAGE

HUM

CLG BLOWER SPEED ADJUSTMENT

DEFAULT

ACC

−

I+ I−CRI+ I−

OUTDOOR EQUIPMENT

1−STG COMPRESSOR

W915

2 STAGE

COMPR

DO NOT CUT

2−STG COMPRESSOR

W915

2 STAGE

COMPR

CUT LINK

2−STAGE

COMPRESSOR LINK

(JUMPERS Y1 to Y2)

W915

INDOOR EQUIPMENT

W1W2GY2

ON−BOARD LINK

OPTION SELECTION

A/C UNIT

W951

HEAT PUMP

DO NOT CUT

HEAT PUMP UNIT

W951

HEAT PUMP

CUT LINK

HEAT PUMP LINK

(JUMPERS R to O)

W951

+ 10%

− 10%

DIAGNOSTIC

LED

SureLight

Y1 C C DH L O DSR

HSI/CAI

NO HARMONY ZONING

NO SIGNATURESTAT W/ DS CONNECTION

IGN

CAI1

CAI2

P79

110

4 7

CUT FOR

OPTION

SELECTION

W915

2 STAGE

COMPR

W951 HEAT

PUMP

W914

DEHUM

HARMONY

DO NOT CUT

W914

DEHUM

HARMONY

HARMONY ZONING

SIGNATURESTAT W/

DS CONNECTION

CUT LINK

W914

DEHUM

HARMONY

DEHUMIDIFICATION−

HARMONY LINK

(JUMPERS R to DS)

W914

NEUTRALS

CONTINUOUS FAN MODE BLOWER SPEED

MEDIUM−LOW

SPEED (38%)

MEDIUM−HIGH

SPEED

(70%)

LOW

SPEED

(28%)

HIGH SPEED (100%)

COOLING MODE BLOWER SPEED

HIGH

SPEED

MEDIUM−HIGH

SPEED

MEDIUM−LOW

SPEED

LOW

SPEED

COOLING MODE BLOWER RAMPING

OPTION A

OFF−50%−82%−

100%−50%−OFF

OPTION B

OFF−82%−100%−OFF

OPTION C

OFF−100%−100%−OFF

OPTION D

OFF−100%−OFF

−CUT ON−BOARD LINK (SOLDER TRACE) COMPLETELY THROUGH

BOTH LAYERS ON THE CONTROL BOARD

−LINKS CUT IN ERROR −INSTALL A JUMPER ON THE APPROPRIATE

TERMINALS ON THE TERMINAL STRIP

−PROTECTIVE PLASTIC FILM ON DIP SWITCHES MAY BE

REMOVED FOR EASE IN SETTING OF DIP SW.

* FACTORY DEFAULT

FIGURE 5

Page 7

TABLE 4

Integrated Control Diagnostic Modes

Dispaly Action (when button released)

No change (idle)* Remain in idle mode

Solid “E” Enter diagnostic recall mode

Solid “D” Discharge Air Installed

Solid “F” Enter ﬂ ame signal mode

Solid “P” (variable speed only) Program unit capacity/size (Unit Code)

Two horizontal bars = Soft disable

* No change implies the display will continue to show whatever is currently being displayed for normal operation (blinking decimal, active error code, heat state, etc..)

Diagnostic LED (Figure 5)

The seven-segment diagnostic LED displays operating status, target airﬂ ow, error codes and other information. The table beginning on Page 9 lists diagnostic LED codes.

Diagnostic Push Button (Figure 5)

The diagnostic push button is located adjacent to the seven-segment diagnostic LED. This button is used to enable the Error Code Recall “E” mode and the Flame Signal “F” mode. Press the button and hold it to cycle through a menu of options. Every ﬁ ve seconds a new menu item will be displayed. When the button is released, the displayed item will be selected. Once all items in the menu have been displayed, the menu resumes from the beginning until the button is released.

Error Code Recall Mode

Select ”E” from the menu to access the most recent 10 error codes. Select “c” from the Error Code Recall menu to clear all error codes. Button must be pressed a second time while “c” is ﬂ ashing to conﬁ rm command to delete codes. Press the button until a solid “≡” is displayed to exit the Error Code Recall mode.

Flame Signal Mode

Select ”F” from the menu to access the ﬂ ame signal mode. The integrated control will display the ﬂ ame current on 7 segment LED in in micro amps (uA).

• Flame signal mode is exited after any of the following: Power is reset

• Pressing and holding push button until 3 horizontal lines “≡” are displayed

• 10 minutes after entering the ﬂ ame sense mode.

Program Unit Capacity/Size Mode

After the “P” is selected (by releasing the push button) the integrated control will start ﬂ ashing the “P” on display for 90 seconds. If push button is pressed again and held during that time, the control will start to display characters corresponding to different variable speed furnace models for 3 seconds each. While the wanted character-model is displayed push button has to be released. Selected option will ﬂ ash display for 10 seconds and during that time push button has to be pressed and held for 5 seconds. Once control accepts new setting it will store data in non-volatile memory and reset itself. If 10 seconds expires or push button is held less than 5 seconds, control will exit ﬁ eld test mode and go into idle without changing programming the unit size.

Soft Disable

Soft disabling is when thermostat ﬁ nds a device on the BUS that it does not recognize and the thermostat sends a the device a message to be in soft disabling mode until properly conﬁ gured. Two horizontal bars will display.

Steps to follow if the damper control module is displaying the soft disable code.

1 - Conﬁ rm proper wiring between all devices

(thermostat, damper control module, indoor and outdoor).

2 - Cycle power to the control that is displaying the soft

disable code.

3 - Put the room thermostat through set up.

4 - Go to setup / system devices / thermostat / edit

/ then push reset.

5 - Go to setup / system devices / thermostat / edit /

then push resetAll.

Page 8

TABLE 5

Integrated Diagnostic Codes/Status of Equipment

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

. Idle mode (Decimal blinks at 1 Hertz -- 0.5

second ON, 0.5 second OFF).

A Cubic feet per minute (cfm) setting for

indoor blower (1 second ON, 0.5 second OFF) / cfm setting for current mode displayed.

C Cooling stage (1 second ON, 0.5 second

OFF) / 1 or 2 displayed / Pause / cfm setting displayed / Pause / Repeat codes).

d Dehumidiﬁ cation mode (1 second ON) /

1 second OFF) / cfm setting displayed / Pause / Repeat Codes).

h Heat pump stage (1 second ON, 0.5

second OFF) / % of input rate displayed / Pause / cfm setting / Pause / Repeat codes.

H Gas Heat Stage (1 second ON, 0.5 second

OFF) / 1 or 2 displayed / Pause / cfm setting displayed / Pause / Repeat codes. Blinking during ignition.

dF Defrost mode.

U Discharge Air Temperature

E105 Device communication problem - No other

devices on RS BUS (Communication system).

E110 Low line voltage. Line Voltage Low (Voltage lower than nameplate rating). Check power line

E111 Low line voltage. Reverse line power voltage wiring. System resumes normal operation 5

E112 Ground not detected System shuts down. Provide proper earth ground. System resumes normal

E113 High line voltage. Line Voltage High (Voltage higher than nameplate rating). Provide power

E114 Line voltage frequency out-of-range. No 60 Hertz Power. Check voltage and line power frequency. Correct

E115 Low 24V - Control will restart if the error

recovers.

E116 High 24V. 24 Volt Power High (Range is 18 to 30 volts). Check and correct voltage.

E117 Poor ground detected (Warning only) Provide proper grounding for unit. Check for proper earth ground to the

E120 Unresponsive device. Communication

only.

Equipment is unable to communicate. Indicates numerous message errors. In most cases errors are related to electrical noise. Make sure high voltage power is separated from RSBus. Check for miswired and/or loose connections between the stat, indoor unit and outdoor unit. Check for a high voltage source of noise close to the system. Fault clears after communication is restored.

voltage and correct. Alarm clears 5 seconds after fault recovered.

seconds after fault recovered.

operation 5 seconds after fault recovered.

voltage within proper range. System resumes normal operation 5 seconds after fault recovered.

voltage and frequency problems. System resumes normal operation 5 seconds after fault recovered.

24-Volt Power Low (Range is 18 to 30 volts). Check and correct voltage. Check for additional power-robbing equipment connected to system. May require installation of larger VA transformer to be installed in furnace / air handler. Clears after fault recovered.

Check for proper line voltage (120V, 240V, etc.) to equipment. Clears when control senses proper voltage.

system. Warning only will clear 30 seconds after fault recovered.

Usually caused by delay in outdoor unit responding to indoor unit poling. Recycle power. Check all wiring connections. Cleared after unresponsive device responds to any inquiry.

Page 9

TABLE 5 Continued

Code

E124 Active communicating thermostat signal

Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

Equipment lost communication with the thermostat. Check

missing for more than 3 minutes.

four wiring connections, ohm wires and cycle power at the thermostat. Alert stops all services and waits for heartbeat message from thermostat (subnet controller). Cleared after valid thermostat (subnet controller) message is received.

E125 Control failed self-check, internal error,

failed hardware. Will restart if error recovers. Integrated control not communicating.

Hardware problem on the control. Cycle power on control. Replace if problem prevents service and is persistent. Criti-

cal alert. Cleared 300 seconds after fault recovered. Covers hardware errors (ﬂ ame sense cir- cuit faults, pin shorts, etc.).

E126 Control internal communication problem. Hardware problem on the control. Cycle power on con-

trol. Replace if problem prevents service and is persistent.

Cleared 300 seconds after fault recovered.

E131 Corrupted control parameters (Verify con-

ﬁ guration of system). Communicating only.

Reconﬁ gure the system. Replace control if heating or cool-

ing is not available. Only applicable in the communicating

mode, not in startup. Exit from Commissioning and Execute

‘Set Factory Default mode Control will still operate on default

parameter settings

E180 Outdoor air temperature sensor failure.

Only shown if shorted or out-ofrange.

Compare outdoor sensor resistance to temperature/ resis-

tance charts in unit installation instructions. Replace sensor

pack if necessary. At beginning of (any) conﬁ guration, furnace

or air handler control will sense outdoor air and discharge

air temperature sensor(s). If detected (reading in range),

appropriate feature will be set as ‘installed’ and that could

be seen in ‘About’ screen. In normal operation after control

recognizes sensors, alarm will be sent if valid temperature

reading is lost. To get rid of setting and alarm, redo conﬁ gu-

ration and make sure that temperature sensor is marked as

‘not installed’ in Indoor Unit ‘About’ screen. When Indoor unit

control is replaced, thermostat will ‘tell’ new control if tem-

perature sensor is in system or not. Clears 30 seconds after

fault recovered.

E200 Hard lockout - Rollout circuit open or pre-

viously open.

E201 Indoor blower communication failure - Un-

able to communicate with blower motor.

Correct cause of rollout trip, or replace ﬂ ame rollout switch.

Test furnace operation. Cleared after fault recovered.

Indoor blower communication failure (including power out-

age). Lost communication with indoor blower motor. Possible

causes: motor not powered, loose wiring. Problem may be

on control or motor side. Cleared after fault recovered.

E202 Indoor blower motor mis-match - Indoor

motor horsepower does not match unit capacity.

Incorrect appliance capacity code selected. Check for proper

conﬁ guring under: Unit Size Codes for Furnace/Air Handler

on conﬁ guration guide or in installation instructions. Cleared

after the correct match is detected following a reset. (Re-

move thermostat from system while applying power and re-

programming.)

E203 Appliance capacity / size is NOT pro-

grammed. Invalid unit codes refer to conﬁ guration ﬂ ow chart.

No appliance capacity code selected. Check for proper con-

ﬁ guring under: Unit Size Codes for Furnace on conﬁ guration

guide or in installation instructions. Critical Alert. Cleared af-

ter valid unit code is read following a reset. (Remove thermo-

stat from system while applying power and reprogramming.)

E204 Gas valve mis-wired. Check gas valve operation and wiring. Clears when repaired.

E205 Gas valve control relay contact shorted. Check wiring on control and gas valve. If wiring is correct,

replace control.

Page 10

TABLE 5 Continued

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E206 Gas valve second-stage relay failure Furnace will operate on 1st stage for remainder of the

heating demand. Will clear after fault recovered. If unable to operate 2nd stage, replace control.

E207 Hot surface ignitor sensed open. Measure resistance of hot surface ignitor. Replace if

open or not within speciﬁ ed range found in IOM. Re- sumes normal operation after fault is cleared.

E223 Low pressure switch failed open. Check pressure (inches w.c.) of low pressure switch

closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared

E224 Low pressure switch failed closed. Check operation of low pressure switch to see if it is

stuck closed on heat call longer than 150 seconds. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

E225 High pressure switch failed open. Check pressure (inches w.c.) of high pressure switch

closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

E226 High pressure switch failed closed Check operation of high pressure switch closing on heat

call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

E227 Low pressure switch open during trial for ignition

or run mode.

E228 Combustion air inducer calibration failure Unable to perform pressure switch calibration. Check

E229 Ignition on high ﬁ re IFC switched to high ﬁ re ignition because low ﬁ re pres-

E240 Low ﬂ ame current - Run mode. Check micro-amperes of ﬂ ame sensor using control

E241 Flame sensed out of sequence - Flame still pres-

ent.

E250 Limit switch circuit open. Check for proper ﬁ ring rate on furnace. Ensure there is

E252 Discharge air temperature too high (gas heat only). Check temperature rise, air ﬂ ow and input rate. Cleared

E270 Soft lockout - Exceeded maximum number of re-

tries. No ﬂ ame current sensed.

Check pressure (inches w.c.) of low pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Resumes normal operation after fault is cleared.

vent system and pressure switch wiring connections. Resumes normal operation after fault is cleared.

sure switch did not close in allowed time. No action is needed.

diagnostics or ﬁ eld-installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground. Alert clears after current heat call has been completed.

Shut off gas. Check for gas valve leak. Replace, if necessary. Alert clears when fault is recovered.

no blockage in heater. Check for proper air ﬂ ow. If limit not closed within 3 minutes, unit will go into 1-hour soft lockout. Resumes normal operation after fault is cleared.

when heat call is ﬁ nished.

Check for proper gas ﬂ ow. Ensure that ignitor is lighting burner. Check ﬂ ame sensor current. Clears when heat call ﬁ nishes successfully.

Page 11

TABLE 5 Continued

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E271 Soft lockout - Exceeded maximum number of re-

tries. Last retry failed due to the pressure switch opening.

E272 Soft lockout - Exceeded maximum number of re-

cycles. Last recycle due to the pressure switch opening.

E273 Soft lockout - Exceeded maximum number of re-

cycles. Last recycle due to ﬂ ame failure.

E274 Soft lockout - Exceeded maximum number of re-

cycles. Last recycle failed due to the limit circuit opening or limit remained open longer than 3 minutes

E275 Soft lockout - Flame sensed out of sequence.

Flame signal is gone.

E276 Watchguard calibration failure. Unable to perform pressure switch calibration. Check vent

E290 Ignitor circuit fault - Failed ignitor or triggering cir-

cuitry.

E291 Heat air ﬂ ow restricted below the minimum. Check for dirty ﬁ lter and air ﬂ ow restriction. Check blower

E292 Indoor blower motor unable to start due to ob-

structed wheel, seized bearings.

E294 Combustion air inducer over current. Check combustion blower bearings, wiring and amps. Re-

E295 Indoor blower motor temperature is too high. Indoor blower motor over temperature (motor tripped on

E310 Discharge error temperature sensor failure. Only

shown if shorted or out of range.

E311 Heat rate reduced to match indoor blower air ﬂ ow. Warning Only. Furnace blower in cutback mode due to

Check operation of low pressure switch to see if it is stuck closed on heat call. Check pressure (inches w.c.) of high pressure switch closing on heat call. Measure operating pressure (inches w.c.). Inspect vent and combustion air inducer for correct operation and restriction. Clears when heat call ﬁ nishes successfully.

Check micro-amperes of ﬂ ame sensor using control diag- nostics or ﬁ eld-installed mode. Clean or replace sensor. Measure voltage of neutral to ground to ensure good unit ground. Clears when heat call ﬁ nishes successfully.

Shut down system. 1-hour soft lockout. Check ﬁ ring rate and air ﬂ ow. Check for blockage. Clears when heat call ﬁ nishes successfully.

Shut off gas. Check for gas valve leak. 1-hour soft lockout. Clears when ﬂ ame has been proven stable.

system and pressure switch wiring connections. 1-hour soft lockout. Clears when calibration has ﬁ nished successfully.

Measure resistance of hot surface ignitor. Replace if open or not within speciﬁ cations. 1-hour soft lockout. Clears when ﬂ ame has been proven stable.

performance. 1-hour soft lockout. Cleared when heat call ﬁ nishes successfully.

Indoor blower motor unable to start (seized bearing, stuck wheel, etc.). Replace motor or wheel if assembly does not operate or meet performance standards. 1-hour soft lockout. Clears after circulator successfully starts.

place if does not operate or does not meet performance standards. Clears after inducer current is sensed to be inrange after the ignition following the soft lockout or reset.

internal protector). Check motor bearings and amps. Replace if necessary. Cleared after blower demand is satisﬁ ed.

Compare outdoor sensor resistance to temperature/ resistance charts in installation instructions. Replace sensor if necessary. Cleared in Communicating mode: 30 seconds after fault recovered. In Non- Communicating mode: Cleared after the current heat call is completed.

restricted airﬂ ow. Reduce ﬁ ring rate every 60 seconds to match available CFM. Check ﬁ lter and duct system. To clear, replace ﬁ lter if needed or repair/ add duct. 2-stage controls will reduce ﬁ ring rate to 1st stage. Clears when heat call ﬁ nishes successfully.

Page 12

TABLE 5 Continued

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E312 Restricted air ﬂ ow in cooling or continu-

ous fan mode is lower than cfm setting.

E313 Indoor or outdoor unit capacity mismatch.

Communication only.

E331 Global network connection - Communica-

tion link problem.

E334 Relay “Y1” stuck on interated control. Replace integrated control.

E347 No 24 Volt output on Y1 of ”integrated

control” with non communicating outdoor unit.

E348 No 24 Volt output on Y2 of ”integrated

control” with non?communicating outdoor unit.

E349 No 24 Volts between R & O on ”integrated

control” with non communicating outdoor unit (Dual fuel module required for heat pump application

E370 Interlock switch sensed open for 2 min-

utes.

E400 LSOM - Compressor internal overload

tripped.

E401 LSOM Compressor long run cycle or low

system pressure.

E402 LSOM - Outdoor unit system pressure

trip.

E403 LSOM - Compressor short-cycling. .(Run-

ning less than 4 minutes). Outdoor unit pressure trip

E404 LSOM - Compressor rotor locked. Com-

pressor short-cycling. (Running less than 4 minutes).

E405 LSOM - Compressor open circuit. Compressor circuit open (due to power disconnection, open fuse,

Warning Only. Restricted airﬂ ow - Indoor blower is running at a re- duced CFM (Cutback Mode - The variable speed motor has pre-set speed and torque limiters to protect the motor from damage caused by operating outside of design parameters (0 to 0.8” W.C.. total external static pressure). Check ﬁ lter and duct system. To clear, re- place ﬁ lter if needed or repair/add duct. Cleared after the current service demand is satisﬁ ed.

Incorrect indoor/outdoor capacity code selected. Check for proper conﬁ guring in installation instructions. Alarm is just a warning. The system will operate, but might not meet efﬁ ciency and capacity pa- rameters. Alarm will clear when commissioning is exited. Cleared after commissioning is complete.

For Future Use.

Operation stopped. Y1 relay / Stage 1 failed. (Pilot relay contacts did not close or the relay coil did not energize; no input back to IFC chip). Critical Alert. Cleared after reset and Y1 input sensed.

Y2 relay / Stage 2 failed. (Pilot relay contacts did not close or the relay coil did not energize; no input back to IFC chip). Critical Alert. Cleared after reset and Y1 input sensed.

Conﬁ guration link R to O needs to be restored. Replace link or hard- wire. Applicable in non communicating mode. Critical Alert.

Control sees the loss of 24VAC for 2 minutes.Terminate all services and wait for interlock switch to close. The alarm will clear when 24VAC is continuously sensed on DS terminal for a minimum of 10 seconds or on a power reset.

Thermostat demand Y1 is present; but, compressor is not running. Check power to outdoor unit. Clears the error after current is sensed in both RUN and START sensors for at least 2 seconds, or after service is removed, or after power reset.

Compressor ran more than 18 hours to satisfy a single thermostat demand. Critical Alert. Clears the error after 30 consecutive normal run cycles or power reset. Also monitors low pressure switch trips.

Discharge or suction pressure out-of-limits, or compressor overloaded. Clears the error after 4 consecutive normal compressor run cycles.

Compressor runs less than 3 minutes to satisfy a thermostat demand. Clears the error after 4 consecutive normal run cycles or power reset.

Compressor rotor locked up due to run capacitor short, bearings are seized, excessive liquid refrigerant, etc. Clears the error after 4 consecutive normal run cycles or after power reset.

etc.) Clears the error after 1 normalcompressor run cycle.

Page 13

TABLE 5 Continued

Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover

E406 LSOM - Compressor open start circuit. Required amount of current is not passing through Start cur-

rent transformer. Clears the error after current is sensed in START sensor, or after power reset.

E407 LSOM - Compressor open run circuit. Required amount of current is not passing through Run current

transformer. Clears the error after current is sensed in RUN sensor, or 1 normal compressor run cycle, or after power reset.

E408 LSOM - Compressor contactor is welded. Compressor runs continuously. Clears the error after 1 normal

compressor run cycle or after power reset.

E409 LSOM - Compressor low voltage. Secondary voltage is below 18VAC. After 10 minutes, oper-

ation is discontinued. Clears the code after voltage is higher than 20 VAC for 2 seconds or after power reset.

DIP Switch Settings

NOTE - All icomfort settings are set at the icomfort Wi-Fi

thermostat. See icomfort installation instruction. In icomfort communication system all DIP switch and clippable link settings are ignored. For conventional thermostats proceed with DIP switch and clippable link settings as outlined in the following.

Heating Operation DIP Switch Settings Switch 1 -- Thermostat Selection -- This unit may be

used with either a single-stage or two-stage thermostat. The thermostat selection is made using a DIP switch which must be properly positioned for the particular application. The DIP switch is factory-positioned for use with a twostage thermostat. If a single-stage thermostat is to be used, the DIP switch must be repositioned.

a. Select “OFF” for two-stage heating operation controlled by a

two-stage heating thermostat (factory setting);

b. Select “ON” for two-stage heating operation controlled by

a single-stage heating thermostat. This setting provides a timed delay before second-stage heat is initiated.

Switch 2 -- Second Stage Delay (Used with SingleStage Thermostat Only) -- This switch is used to deter-

mine the second stage on delay when a single-stage thermostat is being used. The switch is factory-set in the OFF position, which provides a 7-minute delay before secondstage heat is initiated. If the switch is toggled to the ON position, it will provide a 12-minute delay before secondstage heat is initiated. This switch is only activated when the thermostat selector jumper is positioned for SINGLEstage thermostat use.

Switches 3 and 4 -- Blower-Off Delay -- The blower-on

delay of 30 seconds is not adjustable. The blower-off delay (time that the blower operates after the heating demand has been satisﬁ ed) can be adjusted by moving switches 3 and 4 on the integrated control. The unit is shipped from the factory with a blower-off delay of 90 seconds. The blower off delay affects comfort and is adjustable to atisfy individual applicationsAdjust the blower off delay to achieve a supply air temperature between 90° and 110°F at the exact moment that the blower is de-energized. Longer off delay settings provide lower supply air temperatures; shorter settings provide higher supply air temperatures. Table 6 provides the blower off timings that will result from different switch settings.

TABLE 6

Blower Off Delay Switch Settings

Blower Off Delay

Seconds

60 On Off

90 (factory) Off Off

120 Off On

180 On On

Switch 3 Switch 4

Indoor Blower Operation DIP Switch Settings Switches 5 and 6 -- Cooling Mode Blower Speed -- The

unit is shipped from the factory with the dip switches positioned for high speed (4) indoor blower motor operation during the cooling mode. Table 7 provides the cooling mode blower speeds that will result from different switch settings. Switches 5 and 6 set the blower cfm for secondstage cool. The integrated control automatically ramps down to 70% of the second-stage cfm for ﬁ rst-stage cfm. Refer to tables for corresponding cfm values.

TABLE 7

Cooling Mode Blower Speeds

Speed Switch 5 Switch 6

Low On On

Medium Low Off On

Medium High On Off

High (factory) Off Off

. Switches 7 and 8 -- Cooling Blower Speed Adjust-

ment

-- The unit is shipped from the factory with the dip switches positioned for NORMAL (no) adjustment. The dip switches may be positioned to adjust the blower speed by +10% or

-10% to better suit the application. Table 8 below provides blower speed adjustments that will result from different switch settings. Refer to tables for corresponding cfm values.

Page 14

TABLE 8

Cooling Blower Speed Adjustment

Adjustment Switch 7 Switch 8

+10% (approx) On Off

Factory Default Off Off

-10% (approx) Off Off

Ramping Option C

• Motor runs at 100% until demand is satisﬁ ed.

• Once demand is met, motor runs at 100% for 45 sec-

onds then ramps down to stop.

OFF

100% CFM

COMPRESSOR

DEMAND

100% CFM

45 SEC.

OFF

Switches 9 and 10 -- Cooling Mode Blower Speed Ramping -- Blower speed ramping may be used to en-

hance dehumidiﬁ cation performance. The switches are factory set at option A which has the greatest effect on dehumidiﬁ cation performance. Table 9 provides the cooling mode blower speed ramping options that will result from different switch settings. The cooling mode blower speed ramping options are detailed below.

TABLE 9

Cooling Mode Blower Speed Ramping

Ramping Switch 9 Switch 10

A (Factory) Off Off

BOffOn

COnOff

DOnOn

Ramping Option A (Factory Selection)

• Motor runs at 50% for 30 seconds.

• Motor then runs at 82% for approximately 7-1/2 minutes.

• If demand has not been satisﬁ ed after 7-1/2 minutes, motor runs at 100% until demand is satisﬁ ed.

• Once demand is met, motor runs at 50% for 30 seconds then ramps down to stop.

OFF

1/2 MIN 50% CFM

7 1/2 MIN 82% CFM

COMPRESSOR DEMAND

100% CFM

1/2 MIN 50% CFM

OFF

Ramping Option D

• Motor runs at 100% until demand is satisﬁ ed.

• Once demand is met, motor ramps down to stop.

100% CFM

COMPRESSOR

DEMAND

OFFOFF

Switches 11, 12 and 13 -- Heating Mode Blower Speed

The switches are factory set to the OFF position which provides factory default heat speed. Refer to Table 10 for switches 11, 12 and 13 that provided the corresponding increases or decrease to both high and low heat demand.

TABLE 10

Heating Mode Blower Speeds

Heat Speed Switch 11 Switch 12 Switch 13

Increase 24% On On On

Increase 18% On On Off

Increase 12% On Off On

Increae 6% On Off Off

Factory

Off Off Off

Default

Decrease 6% Off Off On

Decrease

Off On Off

12%

Decrease

Off On On

18%

Switches 14 and 15 -- Continuous Blower Speed --

Table 11 provides continuous blower speed adjustments that will result from different switch settings.

Ramping Option B

• Motor runs at 82% for approximately 7-1/2 minutes. If

demand has not been satisﬁ ed after 7-1/2 minutes,mo- tor runs at 100% until demand is satisﬁ ed.

• Once demand is met, motor ramps down to stop.

OFF

7 1/2 MIN

82%CFM

COMPRESSOR DEMAND

100% CFM

OFF

Page 15

TABLE 11

Continuous Blower Speed

Coninuous Blower Speed Switch 14 Switch 15

28% of High Cool Speed Off On

38% of High Cool Speed

(Factory)

70% of High Cool Speed On Off

100% of High Cool Speed On On

Off Off

+ 35 hidden pages

Lennox SL280UHNV, SL280UH060NV36A, SL280UH080NV48B Series Manual

Specifications and Main Features

Frequently Asked Questions

User Manual