REZNOR LDAP Downflow Unit Heaters Instruction Manual

Table 1. Related Technical Manuals Available from Factory Distributor
Type	Form	PN*
Installation/operation/maintenance	LDAP-IOM	207733
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
Relay kits for multiple heater control	LDAP-CL31,32	1041278
*Also available at www.reznorhvac.com.

WARRANTY

The heater has a 1-year limited warranty. Contact your Distributor for details.

CABINET CONFIGURATIONS

These indirect-fired, indoor, downflow packaged heaters are available in three different configurations, as shown in Figure 1.
UNIT SIZE 400ONE DOWNFLOW HEATER
UNIT SIZE 800ONE HEATER WITH TWO DOWNFLOW HEAT SECTIONS
UNIT SIZE 1200ONE HEATER WITH THREE DOWNFLOW HEAT SECTIONS
Figure 1. Cabinet Configurations

SERIAL NUMBER

NOTE: The serial number is located on the unit’s rating plate.

Decode serial numbers as follows:

All models before JUN 2015:
Serial number sample: BDF 79 X7 N 00000
Elements key number: 1 | 2 | 3 | 4 | 5
Key:
1 = Date code (refer to Table 2)
2 = Ignition system type
3 = Gas valve type
4 = Gas type (N = natural, L = propane)
5 = Consecutive number
All models after MAY 2015:
Serial number sample: BOG 3062 00000
Elements key number: 1 | 2 | 3
Key:
1 = Date code (refer to Table 2)
2 = Plant of manufacture (3060 = Mercer, 3062 = Monterrey)
3 = Consecutive number
Table 2. Serial Number Date Codes (Month and Year)

Year

Month

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

2004

BDA

BDB

BDC

BDD

BDE

BDF

BDG

BDH

BDI

BDJ

BDK

BDL

2005

BEA

BEB

BEC

BED

BEE

BEF

BEG

BEH

BEI

BEJ

BEK

BEL

2006

BFA

BFB

BFC

BFD

BFE

BFF

BFG

BEH

BFI

BFJ

BFK

BFL

2007

BGA

BGB

BGC

BGD

BGE

BGF

BGG

BGH

BGI

BGJ

BGK

BGL

2008

BHA

BHB

BHC

BFID

BHE

BHF

BHG

BHH

BHI

BHJ

BHK

Bill

2009

BIA

BIB

BIC

BID

BIE

BIF

BIG

BIH

BII

BIJ

BIK

BIL

2010

BJA

BJB

BJC

BJD

BJE

BJF

BJG

BJH

BJI

BJJ

BJK

BJL

2011

BKA

BKB

BKC

BKD

BKE

BKF

BKG

BKH

BKI

BKJ

BKK

BKL

2012

BLA

BLB

BLC

BLD

BLE

BLF

BLG

BLH

BLI

BLJ

BLK

BLL

2013

BMA

BMB

BMC

BMD

BME

BMF

BMG

BMH

BMI

BMJ

BMK

BML

2014

BNA

BNB

BNC

BND

BNE

BNF

BNG

BNH

BNI

BNJ

BNK

BNL

2015

BOA

BOB

BOC

BOD

BOE

BOF

BOG

BOH

BOI

BOJ

BOK

BOL

2016

BPA

BPB

BPC

BPD

BPE

BPF

BPG

BPH

BPI

BPJ

BPK

BPL

2017

BOA

BOB

BOC

BOD

BOE

BOF

BOG

BOH

BOI

BOJ

BOK

BOL

2018

BRA

BRB

BRC

BRD

BRE

BRF

BRG

BRH

BRI

BRJ

BRK

BRL

2019

BSA

BSB

BSC

BSD

BSE

BSF

BSG

BSH

BSI

BSJ

BSK

BSL

2020

BTA

BIB

BTC

BTD

BTE

BTF

BTG

BTH

BTI

BTJ

BTK

BTL

2021

BUA

BUB

BUC

BUD

BUE

BUF

BUG

BUH

BUI

BUJ

BUK

BUL

2022

BVA

BVB

BVC

BVD

BVE

BVF

BVG

BVH

BVI

BVJ

BVK

BVL

2023

BWA

BWB

BWC

BWD

BWE

BWF

BWG

BWH

BWI

BWJ

BWK

BWL

2024

BXA

BXB

BXC

BXD

BXE

BXF

BXG

BXH

BXI

BXJ

BXK

BXL

2025

BYA

BYB

BYC

BYD

BYE

BYF

BYG

BYH

BYI

BYJ

BYK

BYL

2026

BZA

BZB

BZC

BZD

BZE

BZF

BZG

BZH

BZI

BZJ

BZK

BZL

2027

CAA

CAB

CAC

CAD

CAE

CAF

CAG

CAH

CAI

CAJ

CAK

CAL

2028

CBA

CBB

CBC

CBD

CBE

CBF

CBG

CBH

CBI

CBJ

CBK

CBL

2029

CCA

CCB

CCC

CCD

CCE

CCF

CCG

CCH

CCI

CCJ

CCK

CCL

2030

CDA

COB

CDC

COD

CDE

CDF

CDG

CON

CDI

CDJ

CDK

CDL

2031

CEA

CEB

CEC

CED

CEE

CEF

CEG

CEH

CEI

CEJ

CEK

CEL

2032

CFA

CFB

CFC

CFD

CFE

CFF

CFG

CFH

CFI

CFJ

CFK

CFL

2033

CGA

CGB

CGC

CGD

CGE

CGF

CGG

CGH

CGI

CGJ

CGK

CGL

2034

CHA

CHB

CHC

CHD

CHE

CHF

CHG

CHH

CHI

CHJ

CHK

CHL

2035

CIA

CIB

CIC

CID

CIE

CIF

CIG

CIH

CII

CIJ

CIK

CIL

ELECTRICAL COMPONENTS

VENTER ASSEMBLY (UNIT SIZES 800 AND 1200)Figure 2. Electical Components (Refer to Table 3)

Table 3. Electrical Components
Item No.	Component	Description	Unit Size
			400/800/1200
			PN (Quantity)*
1	Terminal board	24V. 7-pole	164545
2	Destratification relay SPST	24V coil, with base (PN 211415). units manufactured after AUG 2011	211411
		24V coil. units manufactured before SEP 2011	98118
2A	Relay replacement kit	Destratification relay, replaces PN 98118	983527
3	Vent permissive relay. SPST	(AK2), with base (PN 211415) units manufactured after AUG 2011	–	211413
		230V (AK3), with base (PN 711415), units manufactured after AUG 2011		211414
		Units manufactured before SEP 2011	130821
3A	Rela re dacement kit	Vent iermissive relay relaces PN 130821	263529
4	Limit control	240T, silver dot	202048
5	Terminal strip	7-pole	164544 (2)1 164544 (5)1 164544 (7)
6	Sensor	Flame	195292
7	Heat permissive relay. SPST	24V coil . with base (PN 711415), units manufactured after AUG 2011	711411
		24V coil, units manufactured before SEP 2011	98118
7A	Relay replacement kit	Heat permissive relay, replaces PN 98118	263527
8	Ignitor		175272
9	Fan permissive relay SPDT	208V (AK2). with base (PN 211415), units manufactured after AUG 2011	–	211413
		230V (AK3) with base (PN 211415) units manufactured after AUG 2011		711414
		Units manufactured before SEP 2011	157808
9A	Relay replacement kit	Fan permissive relay, replaces PN 157808	263529
10	DSI control board	Circuit board	195265
10A	Fuse	DSI control board	201685
11	Gas valve	Single-stage. natural gas. serial No. code Y3 or Z8	196981
		Two-stage. natural gas. serial No code Y9 or 5A	197067
		Single-stage. propane. serial No code Y5 or 1A	196983
		Two-stage, propane. serial No code Y7 or 3A	197065
12	Transformer	208/240V, 40VA	19453Q
13	Disconnect switch	40A	207948 1 207948 (1)
14	High limit control	Manual reset, 150′, white dot	112753
15	Control	Destratification fan, adjustable	207929 1 707929 (1)
16	Capacitor	Fan motor, 20pF C 370VAC	207582
16A	Boot	Capacitor (Syntex *M-78)	103182
17	Capacitor	Venter motor	195641
18	Fan motor	208230V. 1-HP 3-speed (AOS #F48U34A13)	707734
19	Venter motor	208240V. heat section	196830
20	Pressure switch	Heat section, yellow label, <6000-foot elevation	197028
	Pressure switch	Heat section. light blue label. :.16000-foot elevation	197029
21	Wiring harness (not shown)	5-circuit	208043
22		9-circuit	208224
23	Wire (not shown)	Ignitor	708231
24	Venter motor	Flue collection (AOS *C199)	—	16074
25	Pressure switch	Flue collection box	—	205445
*Quantity is one (1) for unit size 400. two (2) for unit size 800. or three (3) for unit size 1200 unless otherwise indicated.
**May also use field-supplied fuse, type ATC or ATO 3, color violet.

ELECTRICAL COMPONENTS—CONTINUED

Item 1: Terminal Board	Item 5: Terminal Strip	Item 11: Gas Valve
Items 2, 3, 7, and 9: Relay and Base	Item 6: Flame Sensor	Item 11: Gas Valve
Item 4: Limit Control	Item 8: Ignitor	Item 12: Transformer	Item 13: DisconnectSwitch
Item 11: DSI Control Board	Item 15: Fan Control	Item 14: High Limit Control	Item 17: Venter Motor Capacitor
Item 20: Pressure Switch, Heat Section

Figure 3. Individual Electrical Components (Refer to Table 3)

VENTER COMPONENTS

NOTES:
For the flue collection box section venter motor and wheel assembly:

Do not use the key provided with the motor.

Locate the setscrew on the wheel approximately 180° from the keyway in the motor. Torque the setscrew to 125 (±5) inch-pounds.

HEAT SECTION VENTER MOTOR AND WHEEL ASSEMBLYFLUE COLLECTION BOX SECTION VENTER MOTOR AND WHEEL ASSEMBLYFigure 4. Venter Components (Refer to Table 4)
VENTER COMPONENTS—CONTINUED

Table 4. Venter Components
Item No.	Component	Description	Unit Size
			400	800	1200
			PN (Quantity)*
Heat Section
1	Housing (not shown)	Venter	209205
1A	Gasket (not shown)	Venter housing	196013
2	Pressure tap (not shown)	Static	116043 (2)	116043 (4)	116043 (6)
3	Venter motor	208/240V (see Figure 2)	236163
4	Mounting bracket**	Venter	195072
5	Isolator	Venter	194534 (3)	194534 (6)	194534 (9)
6	Isolator bushing	Venter	194803 (3)	194803 (6)	194803 (9)
7	Plate	Venter motor	194910
8	Gasket	Venter motor plate	201472
9	Clip**	Venter motor	194805 (3)	194805 (6)	194805 (9)
9A	Venter motor clip screw**	Slotted, #8-32 × 1/2	92851 (3)	194806 (6)	194806 (9)
10	Venter motor plate screw	#10-24 × 3/4	202949 (3)	202949 (6)	202949 (9)
10A	Hex nut	#10-24	111377 (3)	111377 (6)	111377 (9)
11	Wheel	Venter	195666
12	Fan	Cooling	196035
Flue Collection Box Section
13	Housing	Venter	—	151343 (1)
13A	Gasket	Venter (not shown)		149857 (1)
14	Motor and wheel assembly	Venter		1024267 (1)
14A	Motor	Venter (see Figure 2 and Figure 3)		16074 (1)
14B	Base assembly	Venter motor		207837 (1)
14C	Capscrew	Hex head, 1/4-20 × 3/4		16246 (4)
14D	Washer	Plain, 3/8-inch SAE		6593 (4)
14E	Hex nut	1/4-20, with toothed washer		10650 (4)
14F	Wheel	Venter		8735 (1)
15	Probe assembly	Flow-sensing		151559 (1)
16	Tube, silicone rubber	13 inches long (not shown)		174399 (1)
*Quantity is one (1) for unit size 400, two (2) for unit size 800, or three (3) for unit size 1200 unless otherwise indicated.
Used on units manufactured before** MAR 2015.

FAN COMPONENTS

Figure 5. Fan Components (Refer to Table 5)

Table 5. Fan Components
Item No.	Component	Description	Unit Size
			400	800	1200
			PN (Quantity)*
1	Fan motor	208/230V, 1-HP, 3-speed (A.O. Smith #F48U34A13)	207734
2	Guard	Fan	170086
2A	Screw	Fan guard	96452 (4)	96452 (8)	96452 (12)
2B	Isolator	Fan guard, with washer	96451 (4)	96451 (8)	96451 (12)
2C	Tinnerman nut	Fan guard	54633 (4)	54633 (8)	54633 (12)
2D	Nut	Motor to fan guard	216942 (4)	216942 (8)	216942 (12)
2E	Flat washer	Motor to fan guard	204323 (8)	204323 (16)	204323 (24)
3	Blade	Fan	207729
*Quantity is one (1) for unit size 400, two (2) for unit size 800, or three (3) for unit size 1200 unless otherwise indicated.

HEAT EXCHANGER COMPONENTS

Figure 6. Replacement Heat Exchanger (Refer to Table 6)

Table 6. Heat Exchanger Components
Item No.	Component	Description	Unit Size
			400	800	1200
			PN (Quantity)*
1	Heat exchanger assembly**	With gasket kit, aluminized steel	209209
1	Heat exchanger assembly**	With gasket kit, 409 stainless steel	209210
1A	Gasket kit	Heat exchanger assembly (field-installed)	209211
1B	Header panel gasket	Top	207727
1C		Side	207728 (2)	207728 (4)	207728 (6)
1D		Bottom	207727
2	Panel	Rear	207553	207553	207553
3	Heat exchanger support	Middle	207554	207554	207554
4	Heat exchanger support	Bottom (not shown)	207555	207555	207555
5	Channel	Tube support	207552 (4)	207552 (8)	207552 (12)
*Quantity is one (1) for unit size 400, two (2) for unit size 800, or three (3) for unit size 1200 unless otherwise indicated.

BURNER ASSEMBLY COMPONENTS

Figure 7. Burner Assembly (Refer to Table 7)

Table 7. Burner Assembly Components
Item No.	Component	Description	Unit Size
			400	800	1200
			PN (Quantity)*
1	Burner assembly	Includes venturi tubes	195243
2	Burner shield	Side	195500 (2)
3		Bottom	195521
4		Top	195511
5	Sight-hole cover	Burner shield	10756
6	Support	Burner	196598 (6)	196598 (12)	196598 (18)
7	Burner orifice (not shown)	9.6 mm, natural gas	196897
		5.8 mm, propane	196905
8	Orifice adapter (not shown)	3/4 × 3/8 bushing	194809
8A	Orifice adapter nut (not shown)	1/2-inch	165702
*Quantity is one (1) for unit size 400, two (2) for unit size 800, or three (3) for unit size 1200 unless otherwise indicated.

CABINET COMPONENTS

NOTE: Refer to the CABINET CONFIGURATIONS section.Figure 8. Cabinet Components (Refer to Table 8)

Table 8. Cabinet Components
Item No.	Component	Description	Unit Size
			400	800	1200
			PN (Quantity)*
1	Panel assembly	Bottom	207677	207677	207677
2	Air baffle	Side, interior (not shown)	207610 (2)	207610 (4)	207610 (6)
3	Side panel	Right	207558	207558	207558
4	Side panel	Left	207559	207559	207559
5	Intermediate panel	Left	—	208026 (1)	208026 (2)
6	Intermediate panel	Right	—	208027 (1)	208027 (2)
7	Splice plate	Top and bottom	—	207566	207566 (4)
8	Fan panel	Top	207564	207564 (1)	207564 (1)
8	Fan panel	Top	207564	208044 (1)	208044 (2)
9	Plug	Hole	16452	—
10	Outlet collar	6-inch	195662	—
11	Splice plate	Assembly	—	207731	207731 (4)
12	Flue wrapper assembly	Heat section	207561	207561	207561
12A	Pressure tap	Static, in flue wrapper	116043	116043	116043
12B	Side gasket	Heat section flue wrapper	170037 (2)	170037 (4)	170037 (6)
12C	Top/bottom gasket	Heat section flue wrapper	170039 (2)	170039 (4)	170039 (6)
13	System flue collection box	Bottom and rear	—	207568 (1)	207569 (1)
14		Top and front	—	207570 (1)	207571 (1)
15		End	—	207579 (1)
16		Exhauster end	—	207580 (1)	207581 (1)
17	Gasket	Fan panel/flue collection box	—	207732	207732
18	Door	Access	207572	207572	207572
19	Handle	Door	196881	196881 (1)	196881 (1)
20	Strut	Top of unit	207573 (2)	207574	207575 (2)
21	Louver		195578 (7)	195578 (14)	195578 (21)
22	Hardware package	Hanger/louver, shipped with heater	208347	208834 (1)	208835 (1)
22A	Compression spring	For louvers	195046 (7)	195046 (14)	195046 (21)
22B	Spring nut	A-100-1/2, regular, for hanging heater	158598 (4)
22C	Fitting	AB-288-1/2, U-shape, for hanging heater	207874 (4)
22D	Lockwasher	1/2-inch, for hanging heater	45549 (4)
22E	Hex nut	1/2-13, for hanging heater	45550 (4)
23	Vent cap (not shown)	6-inch (option CC1)	111850	—
23	Vent cap (not shown)	8-inch (option CC1)	—	147149 (1)
24	Touch-up paint (not shown)	11-oz spray can, white	201805
*Quantity is one (1) for unit size 400, two (2) for unit size 800, or three (3) for unit size 1200 unless otherwise indicated.

ACCESSORIES/OPTIONS

Manual Shutoff Valve (Option CE1)

Table 9. Shutoff Valve Components
Component	Description	Unit Size
		400	800, 1200
		PN
Shutoff valve assembly	Includes ball valve and union	208103	208104
Ball valve	1-inch	159725	—
Ball valve	1-1/4-inch	—	159729
Union	1-inch	1141	—
Union	1-1/4-inch	—	5976

Figure 9. Manual Shutoff Valve Assembly (Refer to Table 9)
Gas Conversion Kits
NOTE: Refer to the gas conversion kit installation manual listed in Table 1 for kit components and installation instructions.

Table 10. Gas Conversion Kits
Gas Valve
Single-Stage						Two-Stage
Converting to:
Propane			Natural Gas			Propane	Natural Gas
Unit Size
400	800	1200	400	800	1200	400
Kit PN
208877	208894	208895	208878	208896	208897	208879	208880

Vertical Louver Kits (Option CD32)
NOTES:

The wider side of the louver blade must always be facing out of the heater.

Refer to the vertical louver kit installation manual listed in Table 1 for kit components and installation instructions.

Table 11. Vertical Louver Kits
Unit Size
400	800	1200
Kit PN
208091	208884	208885

Downturn Nozzle Kits (Options CD57, CD58, and CD59)
NOTES:

Option CD57 provides 30-degree air deflection.
Option CD58 provides 60-degree air deflection.

Option CD59, which includes four-way louvers, provides 30-degree air deflection that may vary with louver adjustment.

Figure 10. Downturn Nozzle Assemblies (Refer to Table 12)

Table 12. Downturn Nozzle Kits
Unit Size
400			800			1200
Option
CD57	CD58	CD59	CD57	CD58	CD59	CD57	CD58	CD59
Kit PN
208094	208097	208100	208886	208888	208890	208887	208889	208891

Hanger Kit (Option CK10)Figure 11. Hanger Kit (See Table 13)

Table 13. Hanger Kit Components
Component	Description	PN (Quantity)
Kit package	Swivel hanger kit for 1-inch pipe (option CK10)	207938 (1)
Hanger connector	Swivel assembly	207939 (4)
Lockwasher		45549 (4)

Thermostats (Options CL1 and CL22)Figure 12. Thermostats (Refer to Table 14)

Table 14. Thermostats and Thermostat Accessories
Option	Component	Description	PN
CL1	Single-stage thermostat	24V, 50–90°F, with fan switch	255350
CL1	Locking cover	Option CM1	257464
CL22	Two-stage thermostat	24V, digital, with fan switch	220630
CL22	Locking cover	Option CM1B	257463

Relay Kits (Options CL31 and CL32)
NOTES:

There are two relay kit options, one for controlling two heaters (option CL31) and one for controlling up to five heaters (option CL32).

For unit size 400, up to six heaters can be connected. For unit size 800, three, and for unit size 1200, two.
The relay kit may be installed on the control heater and on up to five additional heaters.

Refer to the relay kit installation manual listed in Table 1 for kit components and installation instructions.

Table 15. Relay Kits
Option
CL31*	CL32**
Kit PN
1041280	1041286
*Includes components for one control unit and one additional unit.
**Includes components for each additional (four maximum) non-control unit.

Specifications and illustrations subject to change without notice or incurring obligations.
Latest version of this manual is available at www.reznorhvac.com.
©2022 Nortek Global HVAC LLC, O’Fallon, MO. All rights reserved.
LDAP-RPL (04-22) 271892-Ahttp://www.reznorhvac.com

Documents / Resources

REZNOR LDAP Downflow Unit Heaters [pdf] Instruction Manual
LDAP Downflow Unit Heaters, LDAP, Downflow Unit Heaters, Unit Heaters, Heaters

References

User Manual

REFERENCES