NordicTrack
Treadmill

Model #NTTL99120 NordicTrack c1800s treadmill

Here are the repair parts and diagrams for your NordicTrack NTTL99120 c1800s treadmill. 

The diagram(s) below can help you find the right part.  If you’d like help, we invite you to call our customer service number at the top of the page, or click chat.

On this page, you can also find any manuals, installation guides and error code tables associated with this model.

For advice on diagnosing problems with appliances, lawn & garden equipment and other products, check out the videos, repair guides and articles in our DIY section.

Save to my profileOwner’s manual

Showing 10 of 156 parts

Treadmill Circuit Breaker, 15-amp

#41

Console/handrail/hood-motor Diagram

$16.14

In Stock

Treadmill Power Cord

#42

Console/handrail/hood-motor Diagram

$15.74

In Stock

Treadmill Safety Key Assembly

#NI17

All parts Diagram

Treadmill safety key assembly

Part #160695
This item is not returnable

$6.50

In Stock

Treadmill Walking Belt

#14

Console/handrail/hood-motor Diagram

$90.02

In Stock

Treadmill Front Roller and Pulley

#8

Console/handrail/hood-motor Diagram

$38.00

In Stock

Treadmill Nut

#9

Console/handrail/hood-motor Diagram

Treadmill nut

Part #119425
This item is not returnable

$2.55

In Stock

Exercise Equipment Rubber Pad

#NI22

All parts Diagram

Exercise equipment rubber pad

Part #157600
This item is not returnable

$2.99

In Stock

Exercise Equipment Reed Switch

#10

Console/handrail/hood-motor Diagram

$10.70

In Stock

Exercise Equipment Bolt

#22

Console/handrail/hood-motor Diagram

Exercise equipment bolt

Part #107503
This item is not returnable

$2.16

In Stock

Treadmill Motor Pulley

#17

Console/handrail/hood-motor Diagram

$39.96

In Stock

Symptoms for treadmills

Choose a symptom to see related treadmill repairs.

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

Repair difficulty
Time required
 45 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.

January 18, 2016

How to use a multimeter to test electrical parts video

By Sears PartsDirect staff

Learn how to use a multimeter to check for wiring problems in an appliance that's not working

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.