Reznor LDAP Owner's manual

Revision: LDAP-IOM (01-22) 207733-A
DOWNFLOW UNIT HEATER
INSTALLATION/OPERATION/MAINTENANCE
Supersedes: I-LDAP (01-19) PN207733R11
MODEL LDAP
⚠ DANGER ⚠
FIRE OR EXPLOSION HAZARD
• Failure to follow safety warnings exactly could result in serious injury, death, or property
damage.
• Improper installation,adjustment,alteration, service,or maintenance can cause serious injury,
death, or property damage.
• Installation and service must be performed by a qualified installer, service agency, or the gas
supplier.
• Be sure to read and understand the installation, operation, and service instructions in this
manual.
• Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or
any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your building.
• Leave the building immediately.
• Immediately call your gas supplier from a phone remote from the building. Follow the gas
supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

2LDAP-IOM (01-22) 207733-A
TABLE OF CONTENTS
GENERAL INFORMATION ............................................................................. 3
References ........................................................................................ 3
Important Safety Information........................................................................... 4
Certification........................................................................................ 4
Warranty .......................................................................................... 4
Installation Codes ................................................................................... 5
Cabinet Configurations ............................................................................... 5
Unit Location....................................................................................... 6
Heater Throw ...................................................................................... 6
Mounting Height Requirements ........................................................................ 7
Hazards of Chlorine ................................................................................. 7
Dimensions ........................................................................................ 8
Clearances .......................................................................................10
Weights.......................................................................................... 10
Combustion Air Requirements ........................................................................11
Acoustical Considerations............................................................................ 12
INSTALLATION .....................................................................................13
Unpacking and Inspection............................................................................13
Pre-Installation Checklist ............................................................................13
Heater Mounting ...................................................................................13
Suspension-Mounting ............................................................................14
Wall-Mounting ..................................................................................14
Piping Connections................................................................................. 15
Gas Supply Pressure............................................................................. 15
Gas Supply Piping............................................................................... 16
Supply Piping Connections ........................................................................ 16
Venting Connections................................................................................ 17
Venting Requirements............................................................................ 18
Vent Pipe Type .................................................................................19
Vent Pipe Size.................................................................................. 19
Vent System Sealing .............................................................................19
Condensation Mitigation ..........................................................................21
Vent System Support Requirements .................................................................21
Vent Terminal (Type of Pipe and Vent Cap) Requirements ...............................................21
Electrical Connections ..............................................................................23
Disconnect Switch Wiring .........................................................................24
Circuit Board Wiring.............................................................................. 24
Fan Motor Wiring................................................................................ 25
Thermostat Wiring ...............................................................................25
Optional Discharge Air Connections.................................................................... 25
Four-Way Discharge Louvers (Option CD32) .......................................................... 25
Discharge Nozzles (Options CD57, CD58, and CD59) ................................................... 25
CONTROLS ........................................................................................26
Pressure Switches ................................................................................. 26
High Temperature Limit Controls ......................................................................27
Automatic-Reset High Temperature Limit Control.......................................................27
Manual-Reset High Temperature Limit Control ......................................................... 27
Combination Gas Valve ............................................................................. 28
Fan Motor ........................................................................................28
Thermostat .......................................................................................28
Multiple Heater Control (Options CL31 and CL32) .........................................................28
Circuit Board (DSI Control Module) ....................................................................28
Air Destratification Fan Control........................................................................ 28

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LDAP-IOM (01-22) 207733-A
TABLE OF CONTENTS—CONTINUED
OPERATION ....................................................................................... 29
Pre-Startup Checklist ...............................................................................29
Startup ..........................................................................................30
Operating Sequences ...............................................................................31
Vent System Testing................................................................................ 33
Post-Startup Checklist ..............................................................................34
ADJUSTMENTS..................................................................................... 34
Pressure Switch Replacement ........................................................................34
Measure and Adjust Manifold (Outlet) Gas Pressure ....................................................... 35
Measure and Adjust Manifold Gas Pressure—Elevation ≤2,000 Feet (≤610 Meters) ............................35
Measure and Adjust Manifold Gas Pressure—Elevation >2,000 Feet (>610 Meters)............................37
MAINTENANCE..................................................................................... 38
Service Checklist ..................................................................................39
Maintenance Procedures ............................................................................39
Burner Maintenance ............................................................................. 39
Burner Orifice Maintenance........................................................................ 40
Heat Exchanger Maintenance ......................................................................41
Ignition System Maintenance ......................................................................41
Maintenance of Fan Motor, Fan Blades, and Fan Guard ................................................. 41
Combination Gas Valve Maintenance ................................................................42
Venter Motor and Wheel Assembly Maintenance ....................................................... 43
Pressure Switch Maintenance...................................................................... 44
High Temperature Limit Control Maintenance..........................................................44
Transformer Maintenance .........................................................................44
Fan Control Maintenance ......................................................................... 44
Vent System Maintenance......................................................................... 44
TROUBLESHOOTING ................................................................................ 44
General Troubleshooting ............................................................................44
Unit Troubleshooting Using DSI Control Module .......................................................... 46
INSTALLATION RECORD (TO BE COMPLETED BY INSTALLER)............................................. 48
GENERAL INFORMATION
•This unit heater has been tested for capacity and efficiency so as to provide many years of safe and dependable
comfort providing it is properly installed and maintained. With regular maintenance, this unit will operate satisfactorily
year after year. Abuse, improper use, and/or improper maintenance can shorten the life of the appliance and
create unsafe hazards.
•To achieve optimum performance and minimize equipment failure, it is recommended that periodic maintenance
be performed on this unit. The ability to properly perform maintenance on this equipment requires certain tools
and mechanical skills.
•The instructions in this manual apply only to model LDAP heaters.
References
Table 1. Related Technical Manuals Available from Factory Distributor
Type Form PN*
Replacement parts LDAP-RPL 271892
Gas conversion kit installation LDAP-GC 208881
Heat exchanger gasket kit installation LDAP-HX 209212
High-elevation pressure switch replacement instructions LDAP-DJ20 208081
Vertical louver kit installation LDAP-CD32 208898
Downturn nozzle kit installation LDAP-CD57,58,59 208899
*Also available at www.reznorhvac.com.

4LDAP-IOM (01-22) 207733-A
GENERAL INFORMATION—CONTINUED
Important Safety Information
Please read all information in this manual thoroughly and become familiar with the capabilities and use of your
appliance before attempting to operate or maintain this unit. Pay attention to all dangers, warnings, cautions, and
notes highlighted in this manual. Safety markings should not be ignored and are used frequently throughout to
designate a degree or level of seriousness.
DANGER: A danger statement describes a potentially hazardous situation that if not avoided, will result in severe
personal injury or death and/or property damage.
WARNING: A warning statement describes a potentially hazardous situation that if not avoided, can result in severe
personal injury and/or property damage.
CAUTION: A caution statement describes a potentially hazardous situation that if not avoided, can result in minor
or moderate personal injury and/or property damage.
NOTE: A note provides important information that should not be ignored.
⚠ WARNING ⚠
• Gas-fired appliances are not designed for use in hazardous atmospheres containing flammable
vapors or combustible dust,in atmospheres containing chlorinated or halogenated hydrocarbons,
or in applications with airborne silicone substances.
• Should overheating occur, or the gas supply control system fail to shut off the flow of gas, shut
off the manual gas valve to the unit before shutting off the electrical supply.
• Do not use this appliance if any part has been under water. Immediately call a qualified service
technician to inspect the appliance and replace any gas control that has been under water.
• Installation should be done by a qualified agency in accordance with these instructions. The
qualified service agency installing this heater is responsible for the installation.
• This appliance is not intended for use by persons with reduced physical, sensory, or mental
capabilities or lack of experience and knowledge, unless they have been given supervision or
instruction concerning use of the appliance by a person responsible for their safety.
• Children should be supervised to ensure that they do not play with the appliance.
Certification
•All model LDAP high-bay packaged heaters are design-certified by ITS for use in industrial and commercial
installations.
•All unit sizes are available for use with either natural or propane gas. The type of gas, the input rate, and the
electrical supply requirement are shown on the heater rating plate. Check the rating plate to determine if the heater
is appropriate for the intended installation.
•Unit is certified as a Category III heater.
Warranty
Refer to the limited warranty form in the literature bag provided with the unit. The warranty is void if:
•Wiring is not in accordance with the diagram furnished with the heater.
•The heater is installed without proper clearance to combustible materials.
•The heater is connected to a duct system or if the air delivery system is modified by other than manufacturer-
designed accessories.

5
LDAP-IOM (01-22) 207733-A
Installation Codes
•These heaters must be installed in accordance with local building codes. In the absence of local codes, in the
United States, the heater must be installed in accordance with the National Fuel Gas Code, ANSI Z223.1. Local
authorities having jurisdiction should be consulted before installation is made to verify local codes and installation
procedure requirements.
•Installations in aircraft hangars should be in accordance with ANSI/NFPA No. 409 (latest edition), Standard for
Aircraft Hangars, in public garages in accordance with ANSI/NFPA No. 88A (latest edition), Standard for Parking
Structures, or in repair garages in accordance with ANSI/NFPA No. 88B (latest edition), Standard for Repair Garages.
•If the heater is being installed in the Commonwealth of Massachusetts, installation must be performed by a licensed
plumber or licensed gas fitter.
Cabinet Configurations
These indirect-fired, indoor, downflow packaged heaters are available in three different configurations, as shown
in Figure 1.
Figure 1. Cabinet Configurations
UNIT SIZE 400
UNIT SIZE 800
UNIT SIZE 1200
ONE DOWNFLOW HEATER
ONE HEATER WITH TWO DOWNFLOW HEAT SECTIONS
ONE HEATER WITH THREE DOWNFLOW HEAT SECTIONS

6LDAP-IOM (01-22) 207733-A
GENERAL INFORMATION—CONTINUED
Unit Location
⚠ CAUTION ⚠
• Unit heaters should not be used in an application where the heated space temperature is below
40°F (4°C). Operating under low ambient conditions may cause condensation to form in the heat
exchanger.
• Do not locate the heater where it may be exposed to water spray, rain, or dripping water.
•Refer to the following sections of this manual to determine where to suspend the heater: Heater Throw, Mounting
Height Requirements, Hazards of Chlorine, Dimensions, Clearances, Weights, Combustion Air Requirements,
Acoustical Considerations, and Venting Connections.
Heater Throw
Figure 2 shows throw patterns for all unit sizes in heat mode at high speed. Table 2 lists throw distances for standard
louvers facing one direction and fully open. Throw pattern changes with louver angle, two-way louver direction, and/
or optional four-way louvers.
Figure 2. Heater Throw Patterns (Refer to Table 2)
Mounting
Height Standard Louvers
30° Nozzle
60° Nozzle
Standard
Louvers
30° Nozzle
60° Nozzle
0 = Rear of Heater Discharge
X = DIST
ANCE FROM 0 TO BEGINNING OF FLOOR COVERAGE
Y = DIST
ANCE FROM 0 TO END OF FLOOR COVERAGE
Z = DIST
ANCE FROM 0 TO POINT WHERE AIR VELOCITY DROPS TO <50 FEET (15.2 METERS) PER MINUTE
Y − X = LENGTH OF FLOOR CO
VERAGE

7
LDAP-IOM (01-22) 207733-A
Table 2. Heater Throw Distances
Mounting
Height
Standard Louvers 30-Degree Nozzle 60-Degree Nozzle
Dimension*
X Y Z X Y Z X Y Z
Feet (Meters)
20 (6.1) 5 (1.5) 55 (16.8) 134 (40.8) 40 (12.2) 90 (27.4) 146 (44.5) 70 (21.3) 125 (38.1) 158 (48.2)
30 (9.1) 8 (2.4) 53 (16.2) 121 (36.9) 44 (13.4) 86 (26.2) 133 (40.5) 76 (23.2) 119 (36.3) 145 (44.2)
40 (12.2) 12 (3.7) 49 (14.9) 109 (33.2) 47 (14.3) 81 (24.7) 120 (36.6) —
50 (15.2) 17 (5.2) 45 (13.7) 96 (29.3) —
*See Figure 2.
Mounting Height Requirements
⚠ WARNING ⚠
If touched, the vent pipe and internal heater surfaces that are accessible from outside the heater
will cause burns. Suspend the heater a minimum of 15 feet (4.6 meters) above the floor.
•For best results, the heater should be mounted with certain rules in mind. In general, a unit should be located 15
to 40 feet (4.6 to 12.2 meters) above the floor. Where two or more units are installed in the same room, a general
scheme of air circulation should be maintained for best results.
•Suspended heaters are most effective when located as close to the working zone as possible, and this fact should
be kept in mind when determining the mounting heights to be used. However, care should be exercised to avoid
directing the discharged air directly on the room occupants.
•Partitions, columns, counters, or other obstructions should be taken into consideration when locating the unit heater
so that a minimum quantity of airflow will be deflected by such obstacles.
Hazards of Chlorine
The presence of chlorine vapors in the combustion air of gas-fired heating equipment presents a potential corrosion
hazard. Chlorine is usually found in the form of freon or degreaser vapors. When chlorine is exposed to flame, it will
precipitate from the compound and go into solution with any condensation that is present in the heat exchanger or
associated parts. The result is hydrochloric acid, which readily attacks all metals including 300 grade stainless steel.
Care should be taken to separate these vapors from the combustion process. This may be done by wise location of
the heater with regard to exhausters or prevailing wind directions. Chlorine is heavier than air. Keep these facts in
mind when determining installation location of the heater in relation to building exhaust systems.

8LDAP-IOM (01-22) 207733-A
GENERAL INFORMATION—CONTINUED
Dimensions
Unit dimensions are shown in Figure 3 and Figure 4. Dimensions of optional nozzle(s) on the discharge opening
(option CD57, CD58, or CD59) are shown in Figure 5.
Figure 3. Dimensions—Unit Size 400
Top
View
Bottom
View
Front
View
Right Side View
17-1/8”
(435mm)
30” (762mm)
14-7/8”
(378mm)
9-1/8”
(232mm)
15-1/4”
(384mm)
34-3/8” (873mm)
Hanger Location
1/2-13 Female Thread
28-1/8”
(714mm)
Air
Destratification
Fan Control
7/8” (22mm)
2-1/8” (54mm)
23”
584mm)
3-1/4”
(83mm)
5-5/8”
(143mm)
23”
(584mm)
Discharge Opening
43-1/2” (1105mm)
9-7/8”
(251mm)
5”
(127mm)
2-5/8”
(67mm)
13-1/8”
(333mm)
Line Voltage Connection
Disconnect Switch
1” NPT Gas Connection
38”
965mm)
1-1/4”
(32mm)
48-1/2”
(1232mm)
9-1/4” (235mm)
Thermostat
Connection
6” Flue
Outlet

9
LDAP-IOM (01-22) 207733-A
Figure 4. Dimensions—Unit Sizes 800 and 1200
F V
B V
R S V
T V
Size 800 - 46” (1168mm)
Size 1200 - 80” (2032mm)
Size 800 - 69” (1753mm);
Size 1200 - 103-3/4” (2635mm)
Hanger Locations
1/2-13 Female Thread 11-7/8”
(302mm)
34-3/4” (883mm) 34-3/4” (883mm) 17-1/8”
(435mm)
8” Flue Outlet
7/8” (22mm)
14-7/8”
(378mm)
28-1/8”
(714mm)
Air
Destratification
FanControl
43-1/2”
(1105mm)
46”
(1166mm)
1-5/8” (41mm)12”
(305mm)
9-7/8”
(251mm)
5” (127mm)
2-5/8”
67mm)
13-1/8”
(333mm)
38”
(965mm)
53”
(1346mm)
13-3/4” (349mm)
1-1/4” (32mm)
Line Voltage
Connection
Disconnect
Switch
1-1/4” Gas
Connection
Flue Collection Box Assembly
Thermostat
Connection
Thermostat
Connection
Thermostat
Connection
5-5/8”
(143mm)
3-1/4” (83mm)
11-3/4”
(298mm)
11-3/4”
(298mm)
23”
(584mm)
23”
(584mm)
23”
(584mm)
23”
(584mm)
Discharge
Opening
Discharge
Opening
Discharge
Opening

10 LDAP-IOM (01-22) 207733-A
GENERAL INFORMATION—CONTINUED
Dimensions—Continued
Table 3. Clearances to Combustibles
Heater
Surface Minimum Clearance (Inches (mm))
Top 12 (305)
Flue connector 6 (152)
Front (access panel) 18 (457)
Rear 2 (51)
Disconnect side 18 (457)
Side 2 (51)
Bottom 60 (1524)
Weights
⚠ WARNING ⚠
Check the supporting structure to be used to verify that it has sufficient load carrying capacity to
support the weight of the unit. Suspend the heater only from the threaded nut retainers or with a
manufacturer-provided kit. Do NOT suspend from the heater cabinet.
NOTE: For unit shipping weight, contact an authorized Factory Distributor.
Before installing the heater, ensure that the supporting structure to be used has sufficient load-carrying capacity to
support the weight (refer to Table 4) of the unit.
Table 4. Unit Weights
Unit Size Pounds (kg)
400 375 (170)
800 805 (365)
1200 1195 (542)
Figure 5. Dimensions—Downturn Nozzle Assemblies
Clearances
Units must be installed so that the clearances listed in Table 3 are provided for with regards to combustion air space,
inspection, and service and for proper spacing from combustible construction. Clearance to combustibles is defined
as the minimum distance from the heater to a surface or object for which it is necessary to ensure that a surface
temperature of 90°F (50°C) above the surrounding ambient temperature is not exceeded. Refer to the dimensions
shown in Figure 3, Figure 4, and Figure 5 when determining clearances to combustibles.
CD57 CD58 CD59
14-1/8 INCHES
(360 mm)
24-3/8 INCHES
(618 mm)
16-1/2 INCHES
(419 mm)