Top 10 Best thermostat cover with lock in 2026

Last Updated - 6/27/2026

🏆Best Choice

Gedreew

Gedreew Large Thermostat Lock Box Cover with Key, Clear Thermostat Cover with Lock Compatible With Honeywell Home Thermostat On Wall, AC Lock Box Cover with Key Fits Thermostats 5"H x 6" W or Smaller

9.8

ChoiceComparer.com Score

9.8

/ 10

Outstanding

Main highlights

•【Safeguard Your Thermostat】The thermostat lock box with key prevent unauthorized adjustments, tampering and damage to thermostat settings by children, tenants, or the public. Enjoy reduced energy costs and significant savings for your household
•【Crystal Clear Durable PC Material】Gedreew thermostat lock box crafted from robust and chemically resistant PC plastic. This thermostat cover with lock offers exceptional durability, UV resistance, and anti-yellowing properties. Enjoy a clear view of your thermostat settings at all times
•【Perfect Fit for Various Thermostats】The thermostat lock box designed to accommodate thermostats measuring 7.28"W x 5.75"H x 2.75"D or smaller. Whether it's for your home, apartment, office, school, hotel, restaurant, or industrial space, our ac lock box cover with key finds its place everywhere, ensuring optimal protection and security
•【Maintaining Temperature Precision】Featuring a four-sided ventilation design, this lock box for thermostat on wall prevents interference with temperature detection, ensuring the accurate performance of your thermostat without compromise
•【Easy Installation】This thermostat cover with lock can be installed without removing the thermostat; May need to mount thermostat off-center within thermostat lock box for access to battery door on select models

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$15.99

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TRJ

TRJ Large Thermostat Lock Box with Key, Clear Thermostat Cover with Lock for Thermostat on Wall, Lockable Thermostat Lock Box Cover, AC Lock Box Cover with Key Fit Thermostats 4" H x 6" W or Smaller

9.7

ChoiceComparer.com Score

9.7

/ 10

Outstanding

Main highlights

•【Tamper-Resistant Design】The thermostat lock box is engineered to deter tampering attempts with its sturdy construction and secure locking mechanism. The thermostat cover with lock prevent unauthorized adjustments, tampering to thermostat settings by children, tenants, or the public
•【Clear Durable PC Material】TRJ thermostat cover with lock crafted from robust and chemically resistant PC plastic. This thermostat lock box with key offers exceptional durability, anti-yellowing properties and UV resistance. Its sturdy design ensures long-term protection for your thermostat, making this ac lock box cover with key an excellent investment for homeowners and property managers
•【Perfect Fit for Various Thermostats】This thermostat lock box measures 7"W x 4.7"H x 2.1"D, compatible with most thermostats and HVAC systems. Whether it's for your home, apartment, school, office, restaurant, hotel, or rental properties, our ac thermostat lock box cover finds its place everywhere, ensuring optimal protection and security
•【Preserve Temperature Precision】Our thermostat lock box features precision-engineered grooves on all four sides, ensuring that the thermostat inside maintains accurate temperature readings. This design prevents interference or obstruction, allowing your heating and cooling system to function optimally without compromise
•【Easy Installation】Installing our thermostat lock box is quick and hassle-free, with all necessary mounting hardware included. This lock box for thermostat on wall can be installed without removing the thermostat; May need to mount thermostat off-center within thermostat lock box for access to battery door on select models

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$12.99

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TRJ

TRJ Thermostat Lock Box with Key, Large Thermostat Cover with Lock for Thermostat on Wall, AC Control Lock Box Cover with Key, Air Conditioner Lockbox Fits Thermostats 4" H x 6" W or Smaller

9.5

ChoiceComparer.com Score

9.5

/ 10

Outstanding

Main highlights

•【Tamper-Proof Design】The TRJ thermostat lock box boasts a sturdy construction and a secure locking mechanism, designed to deter tampering attempts. The thermostat cover prevents unauthorized adjustments, safeguarding against tampering by children, tenants, or the public
•【Crystal Clear Durable PC Material】The thermostat lock box crafted from robust and chemically resistant PC plastic. This thermostat cover with lock offers exceptional durability, UV resistance, and anti-yellowing properties. Enjoy a clear view of your thermostat settings at all times
•【Compatible with Various Thermostats】The thermostat cover designed to accommodate thermostats measuring 7"W x 4.7"H x 2.1"D or smaller. Whether your home, apartment, school, office, restaurant, hotel, church, factory, nursing home or other rental property, our air-conditioned thermostat lock boxes are everywhere to ensure optimal protection and safety
•【Maintains Temperature Accuracy】Featuring a four-sided ventilation design, this lock box for thermostat on wall prevents interference with temperature detection, ensuring the accurate performance of your thermostat without compromise
•【Easy Installation】This thermostat cover with lock can be installed without removing the thermostat; May need to mount thermostat off-center within thermostat lock box for access to battery door on select models

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$12.58

$13.99

-10%

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Honeywell

Honeywell Home CG512A1009 Large Thermostat Guard, Fits Thermostats 8. 25" W x 5. 75" H or Smaller Clear

9.4

ChoiceComparer.com Score

9.4

/ 10

Excellent

Main highlights

•Protect again tampering, damage and unauthorized adjustment of thermostat settings.
•Key lock with inner shelf to prevent tampering. You can mount this thermostat guard horizontally or vertically to fit your thermostat.
•Clear plastic casing is chemical and UV resistant that resists yellowing.
•Fits Honeywell Home thermostats measuring 8. 25"W x 5. 75"H x 2. 75"D or smaller
•May need to mount thermostat off-center within thermostat guard for access to battery door on select models

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$26.22

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ECHDR

Thermostat Lock Box Thermostat Cover Large Thermostat Lock Box with Key Universal Thermostat Cover with Lock AC Lock Box Cover Fits Thermostats 4.72" H x 6.3" W or Smaller

9.2

ChoiceComparer.com Score

9.2

/ 10

Excellent

Main highlights

•【Confirm The Size】: This thermostat lock box is expertly designed to fit various thermostat measuring 6.3"W x 4.72"H x 2.1"D or smaller. PLEASE MAKE SURE YOUR THERMOSTAT SMALLER THAN THIS SIZE
•【Make Your Thermostat Controllable】: The thermostat lock box with key effectively prevents tampering and unauthorized adjustments to your thermostat settings. With its sturdy build and included key, you can rest assured that your thermostat remains protected while keeping your bills in check
•【Clear PE Construction】: The thermostat cover crafted from thickened PE, not only provides robust protection but also UV resistance and anti-yellowing. Enjoy a crystal-clear view of your thermostat settings while keeping them secure
•【Simple Installation】: Installing this lockable thermostat cover is a breeze and can be done without removing the existing thermostat. For select models, you may need to mount the thermostat slightly off-center to access the battery door easily
•【Widely Application】: Ideal for more than just homes, this thermostat lock box is versatile enough for use in restaurants, offices, churches, schools, and industrial settings

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$7.99

$11.99

-33%

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Honeywell

Genuine Honeywell Home CG511A1000 Medium Thermostat Guard, Fits Thermostats 5" H x 6" W or Smaller

9.1

ChoiceComparer.com Score

9.1

/ 10

Excellent

Main highlights

•Protect against tampering, damage and unauthorized adjustment of thermostat settings.
•Fits Honeywell Home thermostat families RTH8xxxx, RTH7xxxx, RTH6xxxx, RTH5xxxx, CT3x and other models measuring 6 1/16 W x 5 1/16 H x 2 5/8 D inches or smaller.
•Actual size of thermostat guard: 6. 5" H x 7. 5" W x 3" D.
•Key lock with inner shelf to prevent tampering.
•Clear plastic casing is chemical and UV resistant that resists yellowing.

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$19.15

$20.99

-9%

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Upifen

Upifen Thermostat Lock Box Square - 5 x 5 Thermostat Cover With Lock, No Screws Thermostat LockBox with Key, Clear AC Thermostat Box Cover, Small Acrylic Lock Box For Thermostat on Wall (5x5x2)

8.9

ChoiceComparer.com Score

8.9

/ 10

Great

Main highlights

•Square Thermostat Cover 5 Inch: This thermostat lock box especially suitable for small round and square ac thermostats size within 5''Wx5''Hx2''D or smaller, such as google nest thermostat, google nest learning thermostat, amazon smart thermostat, ecobee thermostat, honeywell square thermostat. ~ Please double check your ac thermostats dimensions before purchasing~
•Thermostat Guard with Key: One thermostat security cover is equipped with 2 keys, which can effectively prevent your thermostat data from being tampered by children/visitors or employees/colleagues, saving your electricity bill and maintaining your living comfort
•Better Acrylic Material: Our acrylic thermostat lock boxes has no color, is more transparent and stronger, showing the quality of your life than ordinary plastic boxes. It will not change color and yellow, long-term use can also keep the interior clearly visible
•No-Screw Installation: Our locking thermostat cover with key on set provides two installation methods, A-Stick directly on the clean and smooth wall with nano glue, B- Drill holes for installation. And you don't need removing the thermostat from the wall
•Easily Lock Multiple Thermostat Protective Cover: The keys for this thermostat lockbox are universal. Each lockbox comes with 2 keys. If you purchase 10 lockboxes, you only need 1 key to open all 10 boxes on this model, without the need to match specific keys to each lockbox. Perfect for multiple rooms and bulk purchase
•Internal Space (usable area): 5"H x 5" W x 2" D – Fits thermostats up to 5x5x2 inches (square-shaped)
•External Size (overall dimensions): 5.82"H x 6.61" W x 2.4" D – Rectangle shape due to reinforced acrylic thickness and keyhole design.

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$18.99

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Honeywell

Genuine Honeywell Home CG510A Thermostat Guard, Small, Fits Thermostats 4.375H x 4.375W inches or smaller

8.8

ChoiceComparer.com Score

8.8

/ 10

Great

Main highlights

•The Small Thermostat Guard protects your thermostat and prevents others from tampering with your heating and cooling options. Fits Thermostats 4.375H x 4.375W inches or smaller
•This easy-to-install cover includes a lock and key for complete control, as well as air vents for optimum thermostat performance. Key lock with inner shelf to prevent tampering.
•The clear plastic casing is chemical and UV resistant that resists yellowing.
•Ideal for use in a commercial or residential environment.
•Designed to fit over existing thermostat for easy installation.
•Cover fits Honeywell Home Thermostat models RTH8800WF, RTH8560D, CT87K, CT30A, CT31A, CT33A models without the wall plate.
•Outside dimensions: 5.88''W x 5.88''H x 2.50''D
•Interior dimensions: 4.44''W x 4.44''H x 2.25''D

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$20.85

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TayMac

TayMac ZTC100 Clear Plastic Low Profile Locking Thermostat Guard, Heater Guard or Thermostat Cover for Wall with Lock, Thermostat Lock Box with Key for Conservation and Home Improvement

8.6

ChoiceComparer.com Score

8.6

/ 10

Good

Main highlights

•CONVENIENT TO USE - Patented rotating removable hinge makes adjusting the thermostat more convenientby eliminating the need to completely remove the cover
•EASY INSTALLATION - Lid can be removed for ease of thermostat installation; Can be mounted in any one of four directions
•PATENTED HINGE - Includes high strength locking features to ensure that the lid cannot be removed when closed
•INCLUSIONS - Includes tumbler lock with two keys, mounting screws and anchors
•DIMENSIONS - 4-7/16 x 4-7/16 x 2-1/4 inches. Outer dimensions - 5-7/8 x 5-7/8 x 2-1/2 inches. Width Inside- 4.4375 x 4.4375 x 2.25 inches

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$19.98

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iO HVAC Controls

iO HVAC Controls Clear Universal Thermostat Cover Guard With Combination Lock Box, Thermostat Guard For Residential, Hotel, Business, 9" x 8.5" x 2.5"

8.5

ChoiceComparer.com Score

8.5

/ 10

Good

Main highlights

•Prevents tampering with your heating and cooling options
•Highly Ventilated, Heat-resistant, Chemical-resistant
•Made in The USA
•9"L x 5.95"W x 2.65"H

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$24.99

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