Reznor 43254 User manual

Revision: SC-HX (03-22) 221102-A
HEAT EXCHANGER VENTER RESTRICTOR PLATE KIT
INSTALLATION FOR DUCT FURNACES
Supersedes: CP-SC-RSSHX (06-15) PN221102R1
MODELS SC, HSC, AND SCA (SERIES 6)
Table 1. Heat Exchanger Venter Restrictor Plate and Gasket Kit Components
Component
Unit Size
125 175 225 300 350 400
Orifice Diameter (Inches)*
1-3/4 2-1/8 2-3/8 2-3/4 3 3-9/16
PN
Venter restrictor plate 43254 43257 43258 68392 125862 125863
Venter gasket 44695
*As a precaution, verify the diameter of the orifice before installing. If there is a discrepancy, do not install and contact your Distributor.
•These venter restrictor replacement kits are for series 6 SC, HSC, and SCA model units WITH stainless steel heat
exchangers that DO NOT have gas control option AG39, AG40, AG41 or AG42.
•Check the furnace rating plate and wiring diagram to determine if the replacement venter restrictor is required. If
the model number on the rating plate is not prefixed with an E or an S (e.g., SC400 instead of ESC400 or SSC400),
the unit has an aluminized heat exchanger. If the serial number on the rating plate has the suffix MP1, MP2, MP3
or MP4, the unit is equipped with gas control option AG39, AG40, AG41 or AG42.
NOTES:
• The venter restrictor plate adjusts the size of the outlet in the flue duct assembly and must be
changed when replacing an aluminized heat exchanger with a a stainless steel heat exchanger
on certain sizes of series 6 model SC, HSC, and SCA units.
• These replacement kits ARE NOT used on unit sizes 100, 150, 200, and 250.
•Refer to the installation manual provided with the heater for important safety information.
•Ensure that all components listed in Table 1 are available before beginning installation.
INSTALLATION
⚠ DANGER ⚠
• The replacement heat exchanger should be installed by a qualified service agency in compliance
with all codes and requirements of authorities having jurisdiction.
• Improper installation could result in death, serious injury, and/or property damage.The qualified
agency performing this work assumes responsibility for this installation.
• Installation of a replacement heat exchanger requires new heat exchanger gaskets.
Install the venter restrictor replacement kit as follows:
1. Turn OFF gas and electric power.
2. Remove existing venter restrictor plate and gasket:
a. Remove hardware that secures venter motor and wheel assembly to venter housing and carefully remove
assembly from housing.
b. Remove three screws inside venter housing that secure housing to flue duct assembly and remove housing,
venter gasket, and venter restrictor plate.
c. Discard venter restrictor plate and gasket.

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.
SC-HX (03-22) 221102-A
INSTALLATION—CONTINUED
3. Install replacement venter restrictor plate and gasket:
a. Align replacement venter restrictor plate, venter gasket, and venter housing as shown in Figure 1 and secure
plate, gasket, and housing to flue duct assembly using three screws removed in step 2b.
b. Install venter motor and wheel assembly in venter housing as shown in Figure 1 and secure assembly to
housing using hardware removed in step 2a.
Figure 1. Venter Restrictor Plate and Gasket Location
4. Complete replacement heat exchanger installation (refer to installation manual provided with heater):
a. Inspect and clean cabinet, burner, and venter.
a. Replace any components that are not structurally sound.
5. When installation of replacement heat exchanger is complete, start up heater (refer to installation manual
provided with heater):
a. Follow instructions on lighting instruction plate to restart heater.
b. CHECK ALL SAFETY FEATURES FOR PROPER OPERATION.