Honeywell Thermostat Guard

Honeywell Thermostat Guard (Lockable Clear Cover) – Small, Medium or Large

This Honeywell thermostat guard is a clear, lockable cover designed to help stop unwanted changes to heating and cooling settings. It’s a practical add-on for offices, rentals, schools, aged care, retail, and light commercial sites where temperature “tweaks” can cause comfort complaints and extra call-backs.

The cover stays clear (resists yellowing), handles year-round use (UV and chemical resistant), and includes a key lock so only authorised people can access the thermostat.

Best for: HVAC techs, installers, maintenance teams, facility managers, strata/property managers, and capable DIY customers who want to prevent thermostat tampering.

Compatible with: Many Honeywell thermostats and other common wall thermostats. Choose the correct size based on your thermostat’s overall width, height, and depth. If you're running a different model, measure first and confirm clearance before ordering.

Features

• Clear plastic cover that resists yellowing for easy viewing of settings.
• Key lock with inner shelf to help prevent tampering.
• Helps protect preferred AC/heating settings from unwanted changes.
• UV and chemical resistant casing for year-round use.
• Simple installation with mounting hardware included.

Size Guide (Choose Your Variant)

• Small (CG510A1019 / TG510A1001/U): Fits thermostats up to 149mm (H) x 149mm (W) x 64mm (D) or smaller (approx. 4 7/16" W x 4 7/16" H x 2 1/4" D).
• Medium (CG511A1000 / TG511A1000/U) – Part/Code: HLTG511A1000/U: Fits thermostats up to 165mm (H) x 191mm (W) x 75mm (D) or smaller (approx. 6 1/16" W x 5 1/16" H x 2 5/8" D).
• Large (CG512A1009 / TG512A1009/U): Fits thermostats up to 184mm (H) x 248mm (W) x 86mm (D) or smaller (approx. 8.25" W x 5.75" H x 2.75" D).

Technical Specifications

• Cover type: Clear plastic, resists yellowing
• Protection: Lockable cover helps prevent unauthorised access and setting changes
• Material performance: UV and chemical resistant for indoor year-round use
• Install method: Wall-mounted base with cover and lock assembly
• Variants: Small / Medium / Large (see size guide above)

Instructions/ Manuals

• Honeywell Thermostat Guard Small Data Sheet
• Honeywell Thermostat Guard Medium Data Sheet
• Honeywell Thermostat Guard Large Data Sheet

What’s in the Box

• Thermostat guard cover
• Base
• Lock and key
• Mounting hardware

Why “Lockable Thermostat Protection”?

• Stops accidental changes: Helps keep the setpoint consistent across shifts and sites.
• Reduces call-backs: Fewer “it’s too hot/cold” issues caused by tampering.
• Better site control: Only authorised staff can open the cover and adjust settings.
• Clear visibility: You can still see the display and settings through the cover.
• Durable for facilities: UV and chemical resistance helps with day-to-day cleaning and harsh environments.

Using Your Thermostat Guard: Step-by-Step

1. Measure your thermostat’s width, height, and depth to choose Small, Medium, or Large.
2. Check the wall space around the thermostat for clearance (edges, conduit, trunking, door frames).
3. Hold the base in position and mark mounting points.
4. Secure the base using the supplied mounting hardware.
5. Fit the cover onto the base and confirm the thermostat is visible and accessible inside.
6. Lock the cover using the supplied key and confirm the guard sits flush.
7. Store the key with authorised maintenance staff for future access.

Limitations & Safety Notes

• For indoor thermostat protection only. Confirm suitability if the area is exposed to direct weather.
• Always measure first — choose the variant size based on your thermostat’s full dimensions and wall clearance.
• Do not install over damaged, loose, or unsafe wall surfaces.
• Do not use on live electrical components. If the thermostat wiring needs work, isolate power and use a licensed technician.
• Follow relevant workplace safety guidance for installation practices (ladder safety, PPE, and site access).

Shipping & Returns

We ship Australia-wide. For dispatch timeframes, delivery info, and return steps, please see our Shipping & Returns page.

Honeywell Thermostat Guard FAQs

How do I choose between Small, Medium, and Large?

Measure your thermostat’s width, height, and depth, then match it to the maximum size in the Size Guide. If you’re close to the limit, choose the next size up to avoid fit issues.

Will the thermostat still be readable with the cover on?

Yes. The clear cover is designed to keep the display visible while limiting access to buttons and settings.

Does it suit thermostats other than Honeywell?

Often yes, as long as the thermostat fits within the selected size dimensions. Always measure and confirm clearance before ordering.

Is the cover UV and chemical resistant?

Yes. The casing is designed to handle typical indoor conditions, including cleaning and sunlight exposure through windows.

What’s included?

Each size includes the cover, base, lock and key, and mounting hardware.

What should I check if I’m unsure about fit?

Measure the thermostat and check nearby wall obstacles (trunking, conduit, door frames). If you’re unsure, choose the next size up or contact us with your thermostat dimensions.

Why Buy From HVAC Shop?

• Aussie-based support from people who understand HVAC installs and maintenance sites.
• Fast shipping Australia-wide.
• Trade-friendly gear for service, install, and facility maintenance.
• Secure checkout.
• Help choosing the right size for your thermostat and wall space.

Want the complete setup? Shop our Thermostat Accessories range for compatible controls, covers, and installation essentials.