Horizon
Treadmill

Model #DT850 Horizon treadmill

Here are the diagrams and repair parts for Horizon DT850 treadmill, 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 148 parts

    Exercise Equipment Washer

    #H20

    Treadmill assy Diagram

    Exercise equipment washer

    Part #005035-00
    ?
    Manufacturer substitution
    This part replaces MZE0502014. Substitute parts can look different from the original.
    This part replaces MZE0502014
    This item is not returnable
    $2.47

    In Stock

    Exercise Equipment Screw

    #P13

    Treadmill assy Diagram

    Exercise equipment screw

    Part #004415-Z
    ?
    Manufacturer substitution
    This part replaces MZE0103001. Substitute parts can look different from the original.
    This part replaces MZE0103001
    This item is not returnable
    $2.16

    In Stock

    Treadmill Power Cord

    #P07

    Treadmill assy Diagram

    Treadmill power cord

    Part #002169-A
    ?
    Manufacturer substitution
    This part replaces MC0504054A. Substitute parts can look different from the original.
    This part replaces MC0504054A
    $31.99

    In Stock

    Exercise Equipment Screw

    #M10

    Treadmill assy Diagram

    Exercise equipment screw

    Part #004595-00
    ?
    Manufacturer substitution
    This part replaces ME0106026B. Substitute parts can look different from the original.
    This part replaces ME0106026B
    This item is not returnable
    $2.40

    In Stock

    Screw

    #M14

    Treadmill assy Diagram

    Screw

    Part #004590-Z
    ?
    Manufacturer substitution
    This part replaces MZE0106018. Substitute parts can look different from the original.
    This part replaces MZE0106018
    This item is not returnable
    $2.16

    In Stock

    Washer

    #H22

    Treadmill assy Diagram

    Washer

    Part #005232-A
    ?
    Manufacturer substitution
    This part replaces MZE0506020A. Substitute parts can look different from the original.
    This part replaces MZE0506020A
    This item is not returnable
    $2.16

    In Stock

    Exercise Equipment Screw

    #H42

    Treadmill assy Diagram

    Exercise equipment screw

    Part #004724-00
    ?
    Manufacturer substitution
    This part replaces MZE0112034. Substitute parts can look different from the original.
    This part replaces MZE0112034
    This item is not returnable
    $2.88

    In Stock

    Washer

    #H25

    Treadmill assy Diagram

    Washer

    Part #005141-A
    ?
    Manufacturer substitution
    This part replaces MZE0502186A. Substitute parts can look different from the original.
    This part replaces MZE0502186A
    This item is not returnable
    $2.16

    In Stock

    Lock Washer

    #Z14

    Treadmill assy Diagram

    Lock washer

    Part #005019-00
    ?
    Manufacturer substitution
    This part replaces MZE0501029. Substitute parts can look different from the original.
    This part replaces MZE0501029
    This item is not returnable
    $2.16

    In Stock

    Pulse Grip Handlebar End Cap

    #N17

    Treadmill assy Diagram

    Pulse grip handlebar end cap

    Part #000940-A
    ?
    Manufacturer substitution
    This part replaces MB0609092A. Substitute parts can look different from the original.
    This part replaces MB0609092A
    This item is not returnable
    $2.19

    In Stock

    Symptoms for treadmills

    Choose a symptom to see related treadmill repairs.

    Main causes: rear roller out of alignment, damaged walking belt, bad roller
    Main causes: bad control console, wiring failure, bad motor control board
    Main causes: damaged walking belt, improper belt tension, lack of belt lubricant, bad drive motor
    Main causes: no power, bad power cord, tripped or faulty overload switch, bad power switch, wiring failure, bad motor control board
    Main causes: missing safety key, bad control console, wiring failure, faulty motor control board, bad drive motor
    Main causes: faulty sensors, wiring failure, bad control console
    Main causes: damaged walking belt, improper belt tension, bad roller bearing

    Repair guides for treadmills

    These step-by-step repair guides will help you safely fix what’s broken on your treadmill.

    June 1, 2015
    By Lyle Weischwill
    How to replace a treadmill drive motor

    A defective drive motor won't run when activated by the motor controller. Replace the treadmill drive motor if it doesn't run.

    Repair difficulty
    Time required
     15 minutes or less
    June 1, 2015
    By Lyle Weischwill
    How to replace a treadmill motor controller

    Your treadmill motor won't run with a defective motor controller. Replace the motor controller if it doesn't operate the motor correctly.

    Repair difficulty
    Time required
     15 minutes or less
    June 1, 2015
    By Lyle Weischwill
    How to replace a treadmill walking board

    A worn-out walking board creates friction with the walking belt and causes the belt to slow down during use. Replace the walking board if it's worn or damaged.

    Repair difficulty
    Time required
     30 minutes or less

    Articles and videos for treadmills

    Use the advice and tips in these articles and videos to get the most out of your treadmill.

    June 29, 2015

    Easy DIY treadmill repairs

    By Sears PartsDirect staff

    Learn about treadmill repairs that you can easily do yourself.

    June 1, 2015

    Treadmill common questions

    By Sears PartsDirect staff

    These answers to common questions can help you make the most of your treadmill.

    May 10, 2015

    How to maintain a treadmill

    By Sears PartsDirect staff

    Keep your treadmill in shape by following these tips.