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Horizon
Treadmill

Model # DT850 Official Horizon treadmill

Here are the diagrams and repair parts for Official Horizon DT850 treadmill, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

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  • In the search box below, enter all or part of the part number or the part’s name.

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.

Model diagram and schematic

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ALL PARTS
Showing 10 of 148 parts  |
Controller SZTM113MCB
#M03

Treadmill assy diagram

Controller

Part #SZTM113MCB

Replaced by #032669-IF

?
Manufacturer substitution
This part replaces SZTM113MCB. Substitute parts can look different from the original.
This item is not returnable
$220.61 | 
5% OFF Phone Price : $232.61
In Stock
Nut MZE0204005
Nut

Part #MZE0204005

Replaced by #004926-00

?
Manufacturer substitution
This part replaces MZE0204005. Substitute parts can look different from the original.
This item is not returnable
$2.16
In Stock
Bottle Set MF0821002A
#NI

Treadmill assy diagram

Bottle set

Part #MF0821002A

Replaced by #1000092805

?
Manufacturer substitution
This part replaces MF0821002A. Substitute parts can look different from the original.
This item is not returnable
$16.01 | 
11% OFF Phone Price : $18.01
In Stock
Switch MC0701002
#P02

Treadmill assy diagram

Switch

Part #MC0701002

Replaced by #003326-00

?
Manufacturer substitution
This part replaces MC0701002. Substitute parts can look different from the original.
$27.79 | 
18% OFF Phone Price : $33.79
In Stock
Drive Mtr SZTM113MTR
#M01

Treadmill assy diagram

Drive mtr

Part #SZTM113MTR

Replaced by #1000111822

?
Manufacturer substitution
This part replaces SZTM113MTR. Substitute parts can look different from the original.
$300.86 | 
$12.00 OFF Phone Price : $312.86
In Stock
Elastomer MB0502017D
#B48

Treadmill assy diagram

Elastomer

Part #MB0502017D

Replaced by #000768-D

?
Manufacturer substitution
This part replaces MB0502017D. Substitute parts can look different from the original.
$13.60
In Stock
T-wrench MZE1002003
#Z02

Treadmill assy diagram

T-wrench

Part #MZE1002003

Replaced by #005393-00

?
Manufacturer substitution
This part replaces MZE1002003. Substitute parts can look different from the original.
$8.50
In Stock
Elastomer MB0502016D
#B57

Treadmill assy diagram

Elastomer

Part #MB0502016D

Replaced by #000767-D

?
Manufacturer substitution
This part replaces MB0502016D. Substitute parts can look different from the original.
$17.69 | 
10% OFF Phone Price : $19.69
In Stock
Rubber Pad MB0607001B
#M07

Treadmill assy diagram

Rubber pad

Part #MB0607001B

Replaced by #056374-AA

?
Manufacturer substitution
This part replaces MB0607001B. Substitute parts can look different from the original.
This item is not returnable
$5.66
In Stock
Reed Switch MC0403014A
#N13

Treadmill assy diagram

Reed switch

Part #MC0403014A

Replaced by #001963-A

?
Manufacturer substitution
This part replaces MC0403014A. Substitute parts can look different from the original.
This item is not returnable
$3.89
In Stock

Symptoms for treadmills

Choose a symptom to see related treadmill repairs.

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Why won't my treadmill power up?

Main causes: no power, bad power cord, tripped or faulty overload switch, bad power switch, wiring failure, bad motor co…

Read more

Why is my treadmill's walking belt off center?

Main causes: rear roller out of alignment, damaged walking belt, bad roller…

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Why won't my treadmill start even though the console display works?

Main causes: missing safety key, bad control console, wiring failure, faulty motor control board, bad drive motor…

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Why is my treadmill's heart rate sensor not accurate?

Main causes: faulty sensors, wiring failure, bad control console…

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Why does my treadmill have no display?

Main causes: bad control console, wiring failure, bad motor control board…

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Why does my treadmill's walking belt slow down?

Main causes: damaged walking belt, improper belt tension, lack of belt lubricant, bad drive motor…

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Why is my treadmill's walking belt slipping?

Main causes: damaged walking belt, improper belt tension, bad roller bearing…

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Repair guides for treadmills

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

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How to replace a treadmill motor controller

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…

Read more
Repair difficulty
Time required
 15 minutes or less
How to replace a treadmill walking belt

How to replace a treadmill walking belt

A worn walking belt will begin to slow down during use. If your treadmill walking belt is worn out, replace it using the…

Read more
Repair difficulty
Time required
 45 minutes or less
How to replace a treadmill drive motor

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'…

Read more
Repair difficulty
Time required
 15 minutes or less

Effective articles & videos to help repair your fitness & exercise

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

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Top questions about Sears and Sears PartsDirect

Top questions about Sears and Sears PartsDirect

Get answers to frequently asked questions about Sears and Sears PartsDirect.…

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