HOLIDAY ALERT

We will be closing at 12 PM EST on Friday, April 18th, in observance of Good Friday and Easter.
Any orders placed after this time will be processed on Monday, April 21st.
Have a happy Easter weekend!

FREE Ground Shipping on Orders over $100!  Exceptions apply - see details.

UPS SHIPMENT ALERT

Due to the tragic UPS plane crash in Louisville, KY, some UPS shipments--including expedited packages--may be delayed. 
Our thoughts are with those affected by this incident. Thank you for your patience!

WE WANT TO HEAR FROM YOU!

We strive to make improvements that make it easier to serve your boating needs.
We’d like to know more about you and how we can do the best job possible for you.
Please take the time to complete this brief 3-5 minute survey to help us serve you better.

Toggle Nav
  • Sign In
  • Create an Account
My Cart
Search
Menu
Account
Settings
Thermostats

Thermostats

28 Items

Set Descending Direction
View as Grid List
  1. Small Image
    Thermostat | Sierra 18-3556
    SIERRA-18-3556
    Qty In Stock: 0
    MSRP: $41.89 $30.16
    Add to Wishlist
  2. Large Image
    160 degree Thermostat & Sealing Ring | Sierra 18-3539
    SIERRA-18-3539
    Qty In Stock: 6
    MSRP: $54.09 $43.14
    Add to Wishlist
  3. Small Image
    Chrysler 160 Degree Thermostat | Sierra 18-3645
    SIERRA-18-3645
    Qty In Stock: 12
    MSRP: $30.79 $20.85
    Add to Wishlist
  4. Small Image
    Thermostat | Sierra 23-3606
    SIERRA-23-3606
    Qty In Stock: 7
    MSRP: $35.69 $24.13
    Add to Wishlist
  5. Sierra 18-3557 143 Degree Thermostat
    143 degree Thermostat | Sierra 18-3557
    SIERRA-18-3557
    Qty In Stock: 0
    MSRP: $39.49 $29.57
    Add to Wishlist
  6. Sierra 18-3555 160 Degree Thermostat
    160 degree Thermostat | Sierra 18-3555
    SIERRA-18-3555
    Qty In Stock: 0
    MSRP: $26.89 $17.17
    Add to Wishlist
  7. Small Image
    Thermostat | Sierra 23-3600
    SIERRA-23-3600
    Qty In Stock: 1
    MSRP: $10.49 $7.57
    Add to Wishlist
  8. Small
    Thermostat | Sierra 18-3500
    SIERRA-18-3500
    Qty In Stock: 2
    MSRP: $36.49 $25.18
    Add to Wishlist
  9. Small Image
    142 degree Thermostat | Sierra 18-3551
    SIERRA-18-3551
    Qty In Stock: 45
    MSRP: $20.39 $16.44
    Add to Wishlist
  10. Small Image
    160 Degree Thermostat | Sierra 18-3649
    SIERRA-18-3649
    Qty In Stock: 10
    MSRP: $29.29 $19.28
    Add to Wishlist
  11. Small Image
    Thermostat with O-Ring | Sierra 18-3615
    SIERRA-18-3615
    Qty In Stock: 20
    MSRP: $29.69 $21.45
    Add to Wishlist
  12. Sierra 18-3561 Thermostat
    Thermostat | Sierra 18-3561
    SIERRA-18-3561
    Qty In Stock: 3
    MSRP: $20.09 $14.14
    Add to Wishlist
  13. Small Image
    120 degree Thermostat | Sierra 18-3549
    SIERRA-18-3549
    Qty In Stock: 16
    MSRP: $30.39 $28.46
    Add to Wishlist
  14. Sierra 23-3608 Thermostat
    Thermostat | Sierra 23-3608
    SIERRA-23-3608
    Qty In Stock: 5
    MSRP: $20.29 $19.76
    Add to Wishlist
  15. Large
    Thermostat | Sierra 18-3553
    SIERRA-18-3553
    Qty In Stock: 9
    MSRP: $26.49 $20.67
    Add to Wishlist
  16. Small
    Thermostat | Sierra 18-3544
    SIERRA-18-3544
    Qty In Stock: 6
    MSRP: $35.99 $22.96
    Add to Wishlist
  17. Sierra 18-3541 Thermostat
    Thermostat | Sierra 18-3541
    SIERRA-18-3541
    Qty In Stock: 5
    MSRP: $41.29 $27.09
    Add to Wishlist
  18. Small Image
    Thermostat | Sierra 23-3602
    SIERRA-23-3602
    Qty In Stock: 0
    MSRP: $7.59 $7.27
    Add to Wishlist
  19. Small Image
    Thermostat | Sierra 23-3601
    SIERRA-23-3601
    Qty In Stock: 2
    MSRP: $10.69 $10.14
    Add to Wishlist
  20. Sierra 18-3632 Thermostat
    Thermostat | Sierra 18-3632
    SIERRA-18-3632
    Qty In Stock: 2
    MSRP: $42.39 $39.92
    Add to Wishlist
  21. Small Image
    Thermostat | Sierra 23-3604
    SIERRA-23-3604
    Qty In Stock: 14
    MSRP: $12.59 $9.95
    Add to Wishlist
  22. Sierra 18-3535 Thermostat
    Thermostat | Sierra 18-3535
    SIERRA-18-3535
    Qty In Stock: 0
    MSRP: $123.49 $85.80
    Add to Wishlist
  23. Small Image
    160 degree Thermostat | Sierra 18-3558
    SIERRA-18-3558
    Qty In Stock: 7
    MSRP: $39.19 $25.08
    Add to Wishlist
  24. Small Image
    160 degree Thermostat | Sierra 18-3554
    SIERRA-18-3554
    Qty In Stock: 5
    MSRP: $36.89 $26.95
    Add to Wishlist
  25. Small Image
    Thermostat Kit | Sierra 18-3540
    SIERRA-18-3540
    Qty In Stock: 5
    MSRP: $27.59 $19.05
    Add to Wishlist
  26. Sierra 18-3543 Thermostat
    Thermostat | Sierra 18-3543
    SIERRA-18-3543
    Qty In Stock: 10
    MSRP: $24.59 $17.08
    Add to Wishlist
  27. Small Image
    160 Degree Thermostat | Sierra 18-43017
    SIERRA-18-43017
    Qty In Stock: 2
    MSRP: $30.69 $19.94
    Add to Wishlist
  28. Sierra 18-3552 160 Degree Thermostat
    160 degree Thermostat | Sierra 18-3552
    SIERRA-18-3552
    Qty In Stock: 5
    MSRP: $27.49 $19.75
    Add to Wishlist

28 Items

Set Descending Direction
View as Grid List

Sorry, is not an active item in our system. However, we may still be able to help you. Please email us at support@marinepartssource.com or call us at (866)388-0390 for assistance. Please make sure to have the item number handy when you contact us.

My Wish List
Last Added Items
  1. Add to Cart
    Remove This Item
Go to Wish List
You have no items in your wish list.
© 2025 Marine Parts Source. All Rights Reserved.