13HPP Packaged Unit Installation Manual - Lennox

2011 Lennox Industries Inc. 

Dallas, Texas, USA 

INSTALLATION 

INSTRUCTIONS 

13HPP UNITS 

PACKAGED HEAT PUMP UNIT (2−5 TONS) 

506750−01 

06/11 

Supersedes 03/11 

Litho U.S.A. 

RETAIN THESE INSTRUCTIONS 

FOR FUTURE REFERENCE 

WARNING 

Improper installation, adjustment, alteration, service or 

maintenance can cause personal injury, loss of life, or 

damage to property. 

Installation and service must be performed by a licensed 

professional installer (or equivalent) or a service agency. 

WARNING 

If this unit is to be installed in a mobile or manufactured 

home application, the duct system must be sized to 

achieve static pressures within the manufacturer’s 

guidelines. All other installation guidelines must also be 

followed. Failure to do so may result in equipment 

damage, personal injury and improper unit performance. 

WARNING 

Electric shock hazard. Can cause injury 

or death. Before attempting to perform 

any service or maintenance, turn the 

electrical power to unit OFF at disconnect 

switch(es). Unit may have multiple power 

supplies. 

TABLE OF CONTENTS 

Shipping and Packing List . . . . . . . . . . . . . . . . . . . . . 1 

Unit Dimensions − inches (mm) . . . . . . . . . . . . . . . . . 2 

Parts Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Use of Unit as a Construction Heater or 

Air Conditioner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Location Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Rigging and Setting Unit . . . . . . . . . . . . . . . . . . . . . . . 4 

Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

Optional Electric Heat . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Existing Common Vent Systems . . . . . . . . . . . . . . . . 6 

Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Condensate Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Supply and Return Duct Connections . . . . . . . . . . . 8 

Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Blower Speed Settings and Performance Data . . . . 9 

Start−Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Defrost System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

System Performance . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Planned Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Shipping and Packing List 

1 − Assembled packaged heat pump unit 

As soon as the unit is received, it should be inspected for 

possible damage during transit. If you find any damage, 

immediately contact the last carrier. 

CAUTION 

Danger of sharp metallic edges. Can cause injury. Take 

care when servicing unit to avoid accidental contact with 

sharp edges. 

06/11 

Page 1 

506750−01

Unit Dimensions − inches (mm) 

K 

G 

1−5/8 (16) 

Supply 

F 

D 

J 

Supply 

Return 

G 

A 

Return 

F 

E 

F H 

B 

F 

BACK VIEW 

5−1/2 

(140) 

TOP VIEW 

2 (51) 

4 (102) 

Coil Access 

Panel 

L 

Condensate Drain 

3/4 NPT 

C 

LEFT SIDE 

M 

N 

P 

Power Supply 

1−1/8 (29) 

Low Voltage Entry 

7/8 (22) 

Electric Heat 

Power Entry 

RIGHT SIDE 

Blower 

Access 

Panel 

Riggig Hole (8) 

Model No. 

13HPP24A 






A B C D E F G 

in mm in mm in mm in mm in mm in mm in mm 

32−1/2 826 46−1/2 1181 46−1/2 1181 45−5/8 1159 45−5/8 1159 17−1/2 445 11−1/2 292 

34−1/2 876 55−1/2 1410 50−1/2 1283 54−5/8 1387 49−5/8 1260 21−1/2 546 12 305 

Model No. 







H J K L M N P 

in mm in mm in mm in mm in mm in mm in mm 

4 102 4 102 1−3/4 44 15−5/8 397 27−3/4 705 24−7/8 857 9−3/4 248 

6−1/4 159 5−5/8 143 2−3/8 60 17−1/8 435 29−3/4 756 26−7/8 661 15−1/2 394 

Page 2

Parts Arrangement 

OUTDOOR FAN 

INDOOR COIL 

OUTDOOR 

COIL 

BLOWER 

GRILLE 

COMPRESSOR 

BLOWER MOTOR 

DEFROST CONTROL 

TRANSFORMER 

HEATER COVER (FOR 

OPTIONAL ELECTRIC HEAT) 

CAPACITOR 

CONTACTOR 

ELECTRIC HEAT SECTION 

(ORDERED SEPARATELY) 

Figure 1. Parts Arrangement 

General 

These installation instructions are intended as a general 

guide only, for use by an licensed professional installing 

contractor (or equivalent). 

The 13HPP units are single−package heat pump units 

designed for outdoor installation on a rooftop or a slab. 

Electric heat sections are available for separate order. 

The unit must be sized based on heat loss and heat gain 

calculations made according to the methods of the Air 

Conditioning Contractors of America (ACCA). 

The units are shipped assembled. All piping, refrigerant 

charge and electrical wiring are factory−installed and 

tested. The units require electric power, condensate drain 

and duct connections at the point of installation. 

Use of Unit as a Construction Heater or 

Air Conditioner 

Use of this unit as a construction heater or air conditioner 

is not recommended during any phase of construction. 

Very low return air temperatures, harmful vapors and 

operation of the unit with clogged or misplaced filters will 

damage the unit. 

If this unit has been used for heating or cooling of buildings 

or structures under construction, the following conditions 

must be met or the warranty will be void: 

A room thermostat must control the unit. The use of 

fixed jumpers that will provide continuous heating or 

cooling is not allowed. 

A pre−filter must be installed at the entry to the return 

air duct. 

The return air duct must be provided and sealed to the 

unit. 

Return air temperature range between 55°F (13°C) 

and 80°F (27°C) must be maintained. 

Air filters must be replaced and pre−filter must be 

removed upon construction completion. 

The unit components, duct system, air filters and 

evaporator coil must be thoroughly cleaned following 

final construction clean−up. 

Page 3

The unit operating conditions (including airflow, 

cooling operation and heating operation) must be 

verified according to these installation instructions. 

Requirements 

These units must be installed in accordance with all 

applicable national and local safety codes. 

These instructions are intended as a general guide and do 

not supersede local codes in any way. Consult authorities 

having jurisdiction before installation. 

If components are to be added to a unit to meet local codes, 

they are to be installed at the dealer’s and/or customer’s 

expense. 

These units are design−listed by ETL in both the United 

States and Canada as follows: 

For use as a heat pump unit. 

For outdoor installation only. 

For installation on combustible material. 

WARNING 

Product contains fiberglass wool. 

Disturbing the insulation in this product during installation, 

maintenance, or repair will expose you to fiberglass 

wool dust. Breathing this may cause lung cancer. (Fiberglass 

wool is known to the State of California to cause 

cancer.) 

Fiberglass wool may also cause respiratory, skin, and 

eye irritation. 

To reduce exposure to this substance or for further information, 

consult material safety data sheets available 

from address shown below, or contact your supervisor. 

Lennox Industries Inc. 

P.O. Box 799900 

Dallas, TX 75379−9900 

Location Selection 

Use the following guidelines to select a suitable location for 

these units. 

1. Unit is designed for outdoor installation only. Unit must 

be installed so all electrical components are protected 

from water. 

2. Condenser coils must have an unlimited supply of air. 

3. For ground level installation, use a level pre−fabricated 

pad or use a level concrete slab with a minimum 

thickness of 3 inches. The length and width should be 

at least 6 inches greater than the unit base. Do not tie 

the slab to the building foundation. 

4. Maintain level within a tolerance of 1/4 inch (6.35mm) 

maximum across the entire length or width of the unit. 

The heat pump unit foundation should be raised to a 

minimum of 3 inches (75mm) above finish grade. In areas 

which have prolonged periods of temperature below 

freezing and snowfall, the heat pump unit should be 

elevated above the average snow line. Extra precaution 

should be taken to allow free drainage of condensate from 

defrost cycles to prevent ice accumulation. The unit should 

not be located near walkways to prevent possible icing of 

surface from defrost condensate. 

Rigging and Setting Unit 

Exercise care when moving the unit. Do not remove any 

packaging until the unit is near the place of installation. 

Spreaders whose length exceeds the largest dimension 

across the unit MUST be used across the top of the unit. 

Units may also be moved or lifted with a forklift while still in 

the factory−supplied packaging. 

NOTE Length of forks must be a minimum of 42 inches 

(1067mm). 

This unit is shipped with four corner brackets in place on the 

underside of the unit (see figure 2). The two rear corner 

brackets must be removed before unit is installed on a 

field−provided roof curb assembly, provided curb is a split 

level design. 

NOTE Heat pumps are designed to drain water during 

the defrost cycle through holes in the base that are located 

under the outdoor coil. In downflow applications, proper 

clearances and/or drainage collection/management may 

be required at installation to ensure water does not enter 

structure. 

REAR 

CORNER 

BRACKET 

FRONT 

CORNER 

BRACKETS 

Return 

Supply 

REAR 

CORNER 

BRACKET 

FRONT 

CORNER 

BRACKET 

REMOVE REAR CORNER BRACKETS BEFORE INSTALLING ON ROOF 

CURB. LEAVE FRONT CORNER BRACKETS ON UNIT FOR SUPPORT. 

Figure 2. Corner Brackets 

CAUTION 

Before lifting a unit, make sure that the weight is 

distributed equally on the cables so that it will lift evenly. 

Units may also be moved or lifted with a forklift while still in 

the factory−supplied packaging. 

Page 4

Clearances 

All units require certain clearances for proper operation 

and service. Refer to figure 3 for the clearances required 

for combustible construction, servicing, and proper unit 

operation. 

24 

(610) 

24 (610) 

24 (610) 

NOTE TOP CLEARANCE UNOBSTRUCTED MINIMUM 48" (1219) 

0 (0) 

Low voltage control wiring are pigtail leads located on the 

main control box and are color−coded to match the 

connection called out on the wiring schematic. 

Power supply to the unit must comply with all applicable 

codes and NEC or CEC. A fused disconnect switch should 

be field provided for the unit. The switch must be separate 

from all other circuits. If any of the wire supplied with the 

unit must be replaced, replacement wire must be of the 

type shown on the wiring diagram. 

Electrical wiring must be sized to carry minimum circuit 

ampacity marked on the unit. USE COPPER 

CONDUCTORS ONLY. Each unit must be wired with a 

separate branch circuit and be properly protected with a 

fuse or circuit breaker, see unit nameplate. 

WARNING 

Unit is equipped with a single−pole contactor. Line 

voltage is present at all components when unit is not in 

operation. Disconnect all remote electric power supplies 

before opening access panel. Unit may have multiple 

power supplies. Failure to disconnect all power supplies 

could result in personal injury or death. 

Electrical 

Figure 3. Clearances Inches (MM) 

All wiring should be done in accordance with the 

current National Electric Code ANSI/NFPA No. 70 in the 

United States. In Canada, wiring must be done in 

accordance with the current CSA C22.2 Part 1. Local 

codes may take precedence. 

Use wiring with a temperature limitation of 75C minimum. 

Run the 208 or 230 volt, 60 hertz electric power supply 

through a disconnect switch to unit control box and connect 

as shown in the wiring diagram located on the inside of the 

control access panel. Electric power supply must be 

properly protected with either a fuse or circuit breaker, see 

unit nameplate. 

Unit must be grounded with a separate ground conductor. 

See figure 4 for typical field wiring connection. The wiring 

diagram can be found on the unit inside the access panel. 

CAUTION 

When connecting electrical power and control wiring to 

the unit, waterproof type connectors MUST be used so 

that water or moisture cannot be drawn into the unit during 

normal operation. 

WARNING 

Unit must be grounded in accordance with national and 

local codes. Failure to ground unit properly can result in 

personal injury or death. 

See figure 4 for typical field wiring connections and figure 5 

for typical unit wiring diagram. 

If the optional electric heat section is installed, the electric 

heat section requires a separate electrical power supply 

with a disconnect and is properly protected with either a 

fuse or circuit breaker. 

GROUND LUG 

FIELD−SUPPLIED FUSED 

OR CIRCUIT BREAKER 

DISCONNECT 

CONTACTOR 

SINGLE−PHASE 

POWER SUPPLY 

IF 208 VOLT IS SUPPLIED, TRANSFORMER CONNECTIONS MUST BE CHANGED. 

Figure 4. 208/230 Line Voltage Wiring 

Page 5

Optional Electric Heat 

Optional electric heat is available and must be purchased 

separately. Install the electric heat section as outlined in 

the electric heat installation instruction included with heat 

section. 

Follow the basic steps listed below to install the electric 

heat section. Refer to the electric heat installation 

instruction for specific wiring/ heater configuration. 

1. Disconnect the power and open the main control 

access. 

2. Disconnect the plug separating the high voltage wire 

harness. Remove the high voltage wire harness plug 

and discard. 

3. Remove the heater block cover by removing the four 

screws holding it in place. Cut away the insulation 

covering the opening, using the hole in the panel as a 

template. 

4. Insert the heater into the control panel and fasten in the 

same mounting holes. 

5. Plug the heater wiring harness into the wire harness on 

the control assembly. Field wiring of the auxiliary 

heater is separate from the unit power supply. Wire the 

power supply wiring for the heater to the appropriate 

connections on the heater kit. 

Table 1. Electric Heat Kits (208/240V−1ph) 

Heater Model 

Lennox Catalog Number 

5 kW 40K65 

7 kW 40K66 

10 kW 40K67 

15 kW 40K68 

20 kW 40K69 

Existing Common Vent Systems 

The 13HPP packaged heat pump may be used to replace 

an existing gas furnace which is being removed from a 

venting system commonly run with separate gas 

appliances. In this case, the existing vent system is likely 

to be too large to properly vent the remaining attached 

appliances. 

Conduct the following test while each appliance is 

operating and the other appliances (which are not 

operating) remain connected to the common venting 

system. If the venting system has been installed 

improperly, you must correct the system. 

1. Seal any unused openings in the common venting 

system. 

2. Inspect the venting system for proper size and horizontal 

pitch. Determine that there is no blockage, restriction, 

leakage, corrosion, or other deficiencies which could 

cause an unsafe condition. 

3. Close all building doors and windows and all doors 

between the space in which the appliances remaining 

connected to the common venting system are located 

and other spaces of the building. Turn on clothes 

dryers and any appliances not connected to the 

common venting system. Turn on any exhaust fans, 

such as range hoods and bathroom exhausts, so they 

will operate at maximum speed. Do not operate a 

summer exhaust fan. Close fireplace dampers. 

4. Follow the lighting instructions. Turn on the appliance 

that is being inspected. Adjust the thermostat so that 

the appliance operates continuously. 

5. After the main burner has operated for five minutes, 

test for leaks of flue gases at the draft hood relief 

opening. Use the flame of a match or candle. 

6. After determining that each appliance connected to the 

common venting system is venting properly, (step 3) 

return all doors, widows, exhaust fans, fireplace 

dampers, and any other gas−burning appliances to 

their previous mode of operation. 

7. If a venting problem is found during any of the 

preceding tests, the common venting system must be 

modified to correct the problem. 

Resize the common venting system to the minimum 

vent pipe size determined by using the appropriate 

tables in Appendix G. (These are in the current 

standards of the National Fuel Gas Code 

ANSI-Z223.1/NFPA 54 in the USA, and the 

appropriate Category 1 Natural Gas and Propane 

appliances venting sizing tables in the current 

standards of the CSA B149 Natural Gas and Propane 

Installation Codes in Canada.) 

Thermostat 

The room thermostat should be located on an inside wall 

where it will not be subject to drafts, sun exposure or heat 

from electrical fixtures or appliances. Follow 

manufacturer’s instructions enclosed with thermostat for 

general installation procedure. Color−coded insulated 

wires (# 18 AWG) should be used to connect thermostat to 

unit. 

Page 6

Page 7

Condensate Drain 

The 13HPP unit is equipped with a 3/4 inch FPT coupling 

for condensate line connection. Plumbing must conform to 

local codes. Use a sealing compound on male pipe 

threads. 

MINIMUM PITCH 

1 IN. (25 MM) PER 10’ 

(3 M) OF LINE 

TYPICAL CONDENSATE DRAIN 

OPEN 

VENT 

Figure 5. Wiring Diagram − Single Phase 

Air Filter 

UNIT 

An air filter is not factory−supplied with the unit. A 

field−provided air filter must always be in place during unit 

operation. Air filter sizes are shown in table 2. 

This unit is equipped with an internal air filter clip which is 

located in the indoor coil compartment attached to the side 

of the unit drain pan. 

Table 2. Unit Air Filter Sizes inches (mm) 

Unit Model 

Filter Size 

Filter 

Quantity 

−24, −30, −36 28 in. (711) X 24 in. (610) x 1 in. (26) 1 

−42, −48, −60 30 in. (762) X 30 in (762). x 1 in. (26) 1 

Á 

Á 

TRAP MUST BE DEEP ENOUGH TO OFFSET 

MAXIMUM STATIC DIFFERENCE (GENERALLY, 3 

INCHES MINIMUM). 

Á 

Á 

Figure 6. Typical Condensate Drain 

MOUNTING 

FRAME 

The drain line must be properly trapped and routed to a 

suitable drain. See figure 6 for proper drain arrangement. 

The drain line must pitch to an open drain or pump a 

minimum of 1 inch (25.4mm) per 10 feet (3048mm) to 

prevent clogging of the line. Seal around drain connection 

with suitable material to prevent air leakage into return air 

system. 

NOTE Drain line connection may not carry the weight of 

the unsupported drain line. Support the drain line, if 

necessary. 

NOTE Condensate must never drain on a rubberized 

roof. 

Drain piping should not be smaller than drain connection at 

coil. An open vent in drain line will some times be required 

due to line length, friction and static pressure. Drains 

should be constructed in a manner to facilitate future 

cleaning. 

NOTE The condensate drain line MUST be trapped to 

provide proper drainage. 

CAUTION 

Condensate line connection must be hand−tightened. Do 

not use tools. 

Supply and Return Duct Connections 

The duct system should be designed and sized according 

to the methods in Manual Q of the Air Conditioning 

Contractors of America (ACCA). 

A closed return duct system shall be used. This shall not 

preclude use of economizers or outdoor fresh air intake. It 

is recommended that supply and return duct connections 

at the unit be made with flexible joints. 

The supply and return air duct systems should be 

designed for the CFM and static requirements of the job. 

They should NOT be sized by simply matching the 

dimensions of the duct connections on the unit. 

Ducting installed outdoors MUST be insulated and 

waterproofed. 

CAUTION 

When fastening duct system to side duct flanges on unit, 

insert screws through duct flanges only. Do not insert 

screws through casing. Outdoor duct must be insulated 

and waterproofed. 

Compressors 

Units are shipped with the compressor mountings 

factory−adjusted and ready for operation. 

Unit compressors have internal protection. If there is an 

abnormal rise in the compressor temperature, the 

protector will open and the compressor will stop. 

CAUTION 

Do not loosen compressor mounting bolts. 

Page 8

Blower Speed Settings and Performance 

Data 

! WARNING 

Electric shock hazard. Can cause injury or 

death. Before attempting to perform any 

service or maintenance, turn the electrical 

power to unit OFF at disconnect switch(es). Unit 

may have multiple power supplies. 

Factory settings for the blower speed jumpers are given in 

the wiring diagram in figure 5. Use the following tables to 

External Static 

Pressure in. w.g. 

determine the correct air volume for operation in heat and 

cool mode. 

Tap 

Tap 1 

Tap 2 

Tap 3 

Tap 4 and 5 

Table 3. Motor Speed Tap Settings 

Purpose 

Fan Only 

Low Static Cooling 

High Static Cooling 

Table 4. 13HPP24A Blower Performance (Horizontal Airflow 1 ) 

Tap 1 

(Fan Only) 

Tap 2 

(Low Static Cooling) 

Air Volume at Specific Blower Taps (cfm) 

Tap 3 

(High Static Cooling) 

Used for electric heat. Refer to heater label for 

proper selection. 

2 Tap 4 

(Electric Heat) 

2 Tap 5 


0.20 640 830 950 900 1060 

0.30 460 800 910 870 1030 

0.40 370 760 880 830 980 

0.50 − − − 710 840 800 960 

0.60 − − − 640 800 730 930 

0.70 − − − 600 750 690 910 

0.80 − − − 570 700 640 860 

NOTE All air data measured external to unit with dry coil and less filter. 

1 For downflow air volume, add 0.10 in. w.g. to duct static. 

2 Taps 4 and 5 are used with Optional Electric Heat. Refer to Electric Heat nameplate for proper heat tap selection 




Tap 1 

(Fan Only) 

Tap 2 



Tap 3 


2 Tap 4 


2 Tap 5 


0.20 650 1030 1150 1110 1150 

0.30 550 1000 1110 1070 1110 

0.40 490 970 1080 1040 1080 

0.50 430 930 1050 1000 1050 

0.60 − − − 900 1010 970 1010 

0.70 − − − 860 980 950 980 

0.80 − − − 820 960 920 960 







Tap 1 

(Fan Only) 

Tap 2 



Tap 3 


2 Tap 4 


2 Tap 5 


0.20 650 1240 1320 1240 1320 

0.30 590 1200 1260 1200 1260 

0.40 500 1150 1230 1150 1230 

0.50 430 1100 1200 1100 1200 

0.60 − − − 1060 1160 1060 1160 

0.70 − − − 1020 1120 1020 1120 

Page 9

0.80 − − − 980 1080 980 1080 




Page 10




Tap 1 

(Fan Only) 

Tap 2 



Tap 3 


2 Tap 4 


2 Tap 5 


0.20 780 1450 1650 1510 1650 

0.30 690 1370 1570 1430 1570 

0.40 610 1280 1510 1380 1510 

0.50 540 1200 1440 1290 1440 

0.60 − − − 1120 1360 1220 1360 

0.70 − − − 1060 1260 1150 1260 

0.80 − − − 990 1160 1090 1160 







Tap 1 

(Fan Only) 

Tap 2 



Tap 3 


2 Tap 4 


2 Tap 5 


0.20 860 1650 1800 1650 1800 

0.30 760 1600 1750 1600 1750 

0.40 690 1550 1690 1550 1690 

0.50 640 1500 1630 1500 1630 

0.60 − − − 1440 1570 1440 1570 

0.70 − − − 1370 1470 1370 1470 

0.80 − − − 1290 1330 1290 1330 







Tap 1 

(Fan Only) 

Tap 2 



Tap 3 


2 Tap 4 


2 Tap 5 


0.20 1000 1820 1950 1820 1950 

0.30 900 1790 1910 1790 1910 

0.40 800 1730 1860 1730 1860 

0.50 750 1670 1800 1670 1800 

0.60 − − − 1630 1700 1630 1700 

0.70 − − − 1530 1560 1530 1560 

0.80 − − − 1380 1360 1380 1360 




Page 11

Start−Up 

The cooling section is a complete factory package utilizing 

an air−cooled condenser. The system is factory−charged 

with HFC−410A refrigerant. 

PRE−START CHECKLIST: 

1. Make sure refrigerant lines do not rub against the 

cabinet or each other. 

2. Inspect all electrical wiring, both factory− and 

field−installed, for loose connections. 

3. Check voltage at the disconnect switch. Voltage must 

be within the range listed on the unit nameplate. If not, 

consult power company and have voltage condition 

corrected before starting unit. 

4. Recheck voltage with unit running. If power is not 

within the range listed on the unit nameplate, stop the 

unit and consult the power company. Check unit 

amperage. Refer to unit nameplate for correct running 

amps. 

5. Make sure filter is in place before unit start−up. 

COOLING SEQUENCE OF OPERATION 

When the thermostat is in the cooling mode, the O circuit is 

powered which energizes the reversing valve. Upon 

cooling demand, the thermostat closes circuit R and Y to 

close the unit contactor and start the compressor and 

outdoor fan. The thermostat automatically closes R to G 

circuit at the same time. This brings on the indoor blower at 

the selected cooling fan speed. Upon satisfying cooling 

demand, the thermostat will open the above circuits and 

open the main contactor, stopping the compressor and 

outdoor fan. If the unit is equipped with a delay timer, the 

indoor blower will continue to operate for 90 seconds which 

improves system efficiency. 

HEATING SEQUENCE OF OPERATION 

Upon heating demand, the thermostat closes circuit R to Y, 

which closes the unit contactor, starting the compressor 

and outdoor fan. The reversing valve is not energized in the 

heating mode. The thermostat again automatically brings 

on the indoor fan at the selected heating speed at the same 

time. Upon satisfying heating demand, the thermostat 

opens above circuits and stops unit operation. 

System Operation 

UNIT COMPONENTS 

The outdoor unit and indoor blower cycle on demand from 

the room thermostat. If the thermostat blower switch is in 

the ON position, the indoor blower operates continuously in 

the selected continuous blower speed. 

Bi−Flow Liquid line Filter Drier 

The unit is equipped with a large−capacity bi−flow filter drier 

which keeps the system clean and dry. If replacement is 

necessary, order another of the same design and capacity. 

The replacement filter drier must be suitable for use with 

HFC−410A refrigerant. 

Low Pressure Switch 

The 13HPP is equipped with an auto−reset low pressure 

switch which is located on the vapor line. The switch shuts 

off the compressor when the vapor pressure falls below the 

factory setting. This switch, which is ignored during defrost 

operation, closes at pressures at or above 30 + 5 psig (207 

+ 34 kPa) and opens at 10 + 3 psig (69 + 21 kPa). It is not 

adjustable. 

High Pressure Switch 

The 13HPP is equipped with an auto-reset high pressure 

switch (single−pole, single−throw) which is located on the 

liquid line. The switch shuts off the compressor when 

discharge pressure rises above the factory setting. The 

switch is normally closed and is permanently adjusted to 

trip (open) at 590 + 15 psig (4068 + 103 kPa). 

Defrost Thermostat 

The defrost thermostat is located on the liquid line between 

the check/expansion valve and the distributor. When 

defrost thermostat senses 42°F (5.5°C) or cooler, the 

thermostat contacts close and send a signal to the defrost 

control to start the defrost timing. It also terminates defrost 

when the liquid line warms up to 70°F (21°C). 

Page 12

Defrost System 

The defrost system includes a defrost thermostat (S6) and 

a defrost control (CMC1). 

DEFROST CONTROL 

This defrost control includes the combined functions of a 

time/temperature defrost control, defrost relay, time delay, 

diagnostic LEDs, and a terminal strip for field wiring 

connections. 

DEFROST TIMING 

PINS (P1) 

TEST 

PINS 

COMPRESSOR 

DELAY PINS 

REVERSING 

VALVE 

S87 

LOW PRESSURE 

SWITCH 

DEFROST 

THERMOSTAT (S6) 

S4 

HIGH PRESSURE 

SWITCH 

Figure 7. Defrost Control (CMC1) 

DIAGNOSTIC 

LEDS 

24V TERMINAL 

STRIP 

CONNECTIONS 

SERVICE LIGHT 

CONNECTIONS 

The defrost control provides automatic switching from 

normal heating operation to defrost mode and back. When 

the defrost thermostat is closed, the control accumulates 

compressor run time at 30, 60 or 90 minute field adjustable 

intervals. When the selected compressor run time interval 

is reached, the defrost relay is energized and defrost 

begins. 

Defrost Control Timing Pins (P1) 

Each timing pin selection provides a different 

accumulated compressor run time period for one defrost 

cycle. This time period must occur before a defrost cycle 

is initiated. The defrost interval can be adjusted to 30 

(T1), 60 (T2), or 90 (T3) minutes (see figure 24). The 

maximum defrost period is 14 minutes and cannot be 

adjusted. 

NOTE Defrost control part number is listed near the P1 

timing pins. 

Units with defrost control 100269−02: Factory default 

is 60 minutes 

Units with defrost control 100269−04: Factory default 

is 90 minutes 

If the timing selector jumper is missing, the defrost control 

defaults to a 90−minute defrost interval. 

Compressor Delay (P5) 

The defrost control has a field−selectable function to 

reduce occasional sounds that may occur while the unit is 

cycling in and out of the defrost mode. 

Units with defrost control 100269−02: The compressor 

will be cycled off for 30 seconds going in and out of the 

defrost mode when the compressor delay jumper is 

removed. 

Units with defrost control 100269−04: The compressor 

will be cycled off for 30 seconds going in and out of the 

defrost mode when the compressor delay jumper is 

installed. 

NOTE The 30−second compressor feature is ignored 

when the jumper is installed on TEST pins. 

Time Delay 

The timed−off delay is five minutes long. The delay helps 

protect the compressor from short−cycling in case the 

power to the unit is interrupted or a pressure switch opens. 

The delay is bypassed by placing the timer select jumper 

across the TEST pins for 0.5 seconds. 

NOTE The defrost control must have a thermostat 

demand for the bypass function. 

Test Mode (P1−TEST) 

A TEST option is provided for troubleshooting. The TEST 

mode may be started any time the unit is in the heating 

mode and the defrost thermostat is closed or jumpered. If 

the jumper is in the TEST position at power−up, the control 

will ignore the test pins. When the jumper is placed across 

the TEST pins for two seconds, the control will enter the 

defrost mode. If the jumper is removed before an additional 

5−second period has elapsed (7 seconds total), the unit will 

remain in defrost mode until the defrost thermostat opens 

or 14 minutes have passed. If the jumper is not removed 

until after the additional 5−second period has elapsed, the 

defrost will terminate and the test option will not function 

again until the jumper is removed and re−applied. 

Diagnostic LEDs (DS1 and DS2) 

The defrost control uses two LEDs for diagnostics. The 

LEDs flash a specific sequence according to the diagnosis 

(table 10). 

Table 10. Defrost Control Diagnostic LEDs 

DS2 Green DS1 Red Condition 

OFF OFF Power problem 

Simultaneous Slow Flash Normal operation 

Alternating Slow Flash 

5−minute anti−short cycle delay 

OFF Slow Flash Low Pressure Fault 

OFF ON Low Pressure Lockout 

Slow Flash OFF High Pressure Fault 

ON OFF High Pressure Lockout 

Page 13

System Performance 

This equipment is a self contained, factory optimized using 

check expansion valve metered refrigerant system, and 

should require no adjustments when properly installed. If 

however unit 

Ensure unit is installed per manufacturer´s instructions and 

that line voltage and air flows are correct. Refer to table 10 

for proper superheat values. Check superheat settings by 

measuring pressure at the suction line service port. 

Measure pressure at the liquid service port. Take line 

temperature within 2 inches of service port connection to its 

main tube. If unit superheat subcooling varies by more than 

table allowance, check internal seals, service panels and 

duct work for air leaks, as well as restrictions and blower 

speed settings. If unit performance remains questionable, 

remove charge, evacuate to 500 microns, and weigh in 

refrigerant to name plate charge. It is critical that the exact 

charge is re−installed. Failure to comply will compromise 

system performance. If unit performance is still 

questionable, check for refrigerant related problems such 

as, blocked coil or circuits, malfunctioning metering 

devices or other system components. 

80F db / 67F wb RETURN AIR 

Table 11. Suction Superheat Values 

Unit Model No. 

13HPP24 






Table 12. Normal Operating Pressures (Cooling) 

Suction Superheat +/− 3 DEG @ 

82F OD / 80F IDDB 

/ 67F IDWB 

17F 

20F 

16F 

17F 

19F 

19F 

Verify system performance using table 12 as a general 

guide. Table 12 should not be used for charging unit. Minor 

variations in these pressures may be expected due to 

differences in installations. Significant differences could 

mean that the system is not properly charged or that a 

problem exists with some component in the system. 

Used carefully, this table could serve as a useful service 

guide. Data is based on 80F dry bulb / 67F wet bulb return 

air. Allow unit operation to stabilize before taking pressure 

readings. 

Air Temperature Entering Outdoor Coil (F) 

UNIT PRESSURE 65 70 75 80 82 85 90 95 100 105 110 115 


133 136 138 141 142 143 146 148 150 152 154 156 

13HPP30 133 136 139 142 143 144 146 150 151 152 154 156 


Vapor 





253 274 294 315 323 337 361 383 408 428 461 489 



Liquid 




70F RETURN AIR 

Table 13. Normal Operating Pressures (Heating) 

Air Temperature Entering Outdoor Coil (F) 

UNIT PRESSURE 0 5 10 17 20 25 30 35 40 47 50 55 60 


38 45 52 61 65 72 78 85 92 101 105 112 118 

13HPP30 36 43 51 61 66 73 81 88 96 106 111 118 126 


Vapor 





242 252 263 278 284 295 306 316 327 342 348 359 370 



Liquid 




Page 14

Maintenance 

At the start of each cooling season, this equipment should 

be serviced by a licensed professional technician (or 

equivalent). Periodic inspection and maintenance normally 

consists of changing or cleaning filters. 

CONDENSER FAN CLEARANCES 

The hub of the condenser fan blade should be flush with the 

end of the motor shaft to ensure proper clearances and 

performance. This dimension should be checked and the 

fan should be adjusted accordingly any time servicing of 

the outdoor fan system is required. 

AIR FILTER 

Visually inspect vent outlet periodically to make sure that the 

there is no buildup of soot and dirt. If necessary, clean to 

maintain adequate opening to discharge flue products. 

Motors 

Indoor, outdoor fan and vent motors are permanently 

lubricated and require no further lubrication. Motors 

should be cleaned yearly to prevent the accumulation of 

dust and dirt on the windings or motor exterior. 

COIL 

Dirt and debris should not be allowed to accumulate on the 

coil surfaces or other parts in the air conditioning circuit. 

Cleaning should be performed as often as necessary. Use 

a brush, vacuum cleaner attachment, or other suitable 

means. If water is used to clean the coil, be sure the power 

to unit is shut off prior to cleaning. 

NOTE Care should be used when cleaning the coil so 

that the coil fins are not damaged. 

Do not permit the hot condenser air discharge to be 

obstructed by overhanging structures or shrubs. 

Planned Service and (under some conditions) 

cleaning the main burners 

You should expect a service technician to check the 

following items during an annual inspection. Power to the 

unit must be shut off for the service technician’s safety. 

Fresh air grilles and louvers Must be open and 

unobstructed to provide air. 

Unit appearance must be inspected for: 

A Rust, dirt or signs of water 

B Burnt or damage wires 

C Burnt or damage components. 

A good coat of auto wax can enhance the appearance 

of the cabinet. 

Blower access door must be properly in place. 

Return air duct must be properly attached and must 

provide an air seal to the unit. 

Operating performance Unit must be observed 

during operation to monitor proper performance of the 

unit and the vent system. 

Problems detected during the inspection may make it 

necessary to temporarily shut down the unit until the items 

can be repaired or replaced. 

Pay attention to your unit. Situations can arise between 

annual unit inspections that may result in unsafe operation. 

Page 15

13HPP Packaged Unit Installation Manual - Lennox

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