Thermal Zone
Air Handler

Model #AH42B-1 Official Thermal Zone air handler

Here are the diagrams and repair parts for Thermal Zone AH42B-1 air handler, as well as links to manuals and error code tables, if available.

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Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

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For DIY troubleshooting advice and repair guides, visit our repair help section.

    Showing 10 of 15 parts

    Capacitor#8

    Air handlers Diagram

    Capacitor

    Part #621435

    The manufacturer no longer makes this part, and there's no substitute part

    Blower Motor#9

    Air handlers Diagram

    Blower motor

    Part #913358

    The manufacturer no longer makes this part, and there's no substitute part

    Blower Wheel#7

    Air handlers Diagram

    Blower wheel

    Part #667037

    The manufacturer no longer makes this part, and there's no substitute part

    LOWER DOOR WITH INSULATION#12

    Air handlers Diagram

    Lower door with insulation

    Part #499871Z

    The manufacturer no longer makes this part, and there's no substitute part

    Transformer#4

    Air handlers Diagram

    Transformer

    Part #620858

    The manufacturer no longer makes this part, and there's no substitute part

    Blower Relay#3

    Air handlers Diagram

    Blower relay

    Part #620537

    The manufacturer no longer makes this part, and there's no substitute part

    INDOOR COIL ASSEMBLY#13

    Air handlers Diagram

    Indoor coil assembly

    Part #914402

    The manufacturer no longer makes this part, and there's no substitute part

    UPPER DOOR, WITH INSULATION#11

    Air handlers Diagram

    Upper door, with insulation

    Part #372021Z

    The manufacturer no longer makes this part, and there's no substitute part

    CLOSE OFF PLATE (2)#5

    Air handlers Diagram

    Close off plate (2)

    Part #226420

    The manufacturer no longer makes this part, and there's no substitute part

    DRAIN PAN ONLY , "A" COILS, B-CAB#14

    Air handlers Diagram

    Drain pan only , "a" coils, b-cab

    Part #668717

    The manufacturer no longer makes this part, and there's no substitute part

    Articles and videos common to all air handlers

    August 5, 2022

    Introducing new technical repair content that we’re developing for the Sears Technical Institute

    By Lyle Weischwill

    Learn about Sears Technical Institute and the advanced technical content being developed for aspiring appliance techs.