Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Tips to find your model number
Orders

  • Keep track of the models you own in your profile

    Sign in or Register to view or add models

Schedule a repair
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:

  • Click a diagram to see the parts shown on that diagram.
  • 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”.

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

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

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 148 parts  |
Socket MC0703023
#P11

Treadmill assy diagram

Socket

Part #MC0703023

Replaced by #019749-A

?
Manufacturer substitution
This part replaces MC0703023. Substitute parts can look different from the original.
This item is not returnable
$9.62 | 
9% OFF Phone Price : $10.62
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
Breaker MC0702011
#P04

Treadmill assy diagram

Breaker

Part #MC0702011

Replaced by #003346-00

?
Manufacturer substitution
This part replaces MC0702011. Substitute parts can look different from the original.
$14.80
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
Rail Lock MB0643001
#L10

Treadmill assy diagram

Rail lock

Part #MB0643001

Replaced by #001251-F

?
Manufacturer substitution
This part replaces MB0643001. Substitute parts can look different from the original.
This item is not returnable
$3.92
In Stock
Washer MZE0505033
#H27

Treadmill assy diagram

Washer

Part #MZE0505033

Replaced by #005196-00

?
Manufacturer substitution
This part replaces MZE0505033. Substitute parts can look different from the original.
This item is not returnable
$2.26
In Stock
Safety Key S140115001
#N33

Treadmill assy diagram

Safety key

Part #S140115001

Replaced by #016167-Z

?
Manufacturer substitution
This part replaces S140115001. Substitute parts can look different from the original.
$28.05
Back Order
Screw MZE0112034
#H42

Treadmill assy diagram

Screw

Part #MZE0112034

Replaced by #004724-00

?
Manufacturer substitution
This part replaces MZE0112034. Substitute parts can look different from the original.
This item is not returnable
$2.88
In Stock
Arc Washer ME0503001
#Z01

Treadmill assy diagram

Arc washer

Part #ME0503001

Replaced by #005163-00

?
Manufacturer substitution
This part replaces ME0503001. Substitute parts can look different from the original.
This item is not returnable
$2.16
In Stock
Screw MZE0103001
#P13

Treadmill assy diagram

Screw

Part #MZE0103001

Replaced by #004415-Z

?
Manufacturer substitution
This part replaces MZE0103001. Substitute parts can look different from the original.
This item is not returnable
$2.16
In Stock

Symptoms for treadmills

Choose a symptom to see related treadmill repairs.

View all

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…

Read more

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…

Read more

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

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

Read more

Why does my treadmill have no display?

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

Read more

Why does my treadmill's walking belt slow down?

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

Read more

Why is my treadmill's walking belt slipping?

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

Read more

Repair guides for treadmills

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

View all
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.

View all
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.…

Read more

Parts & More