Large Cover Plate & Electrical Box Adaptor for T-Series Thermostats

In this review the focus is on a simple, practical solution for homeowners and installers who need to tidy up wall cutouts left by older thermostats. The THP2400A1080 large cover plate kit is aimed at anyone replacing a landscape thermostat with a modern T-Series unit; its single biggest selling point is straightforward coverage of mismatched or unpainted drywall and electrical box offsets, making the finished installation look clean without extra drywall work. The reviewer found the kit useful for typical retrofit jobs and appreciated the clear compatibility list and included hardware.

Key Features

• Large cover plate size: The 155 x 155 x 6.5 mm plate provides broad coverage so older hole patterns and paint damage are hidden without patching.
• Full kit included: Each package includes four adaptor plates, eight mounting screws and four cover plates so one kit covers multiple rooms or saves for future swaps.
• Electrical box adaptor: The adaptor mounts to single or double gang boxes to align the thermostat flat and secure against the wall for a neat install.
• Compatibility: Designed for T-Series thermostats including T1 through T6Pro and T9, T10 which reduces the guesswork when replacing Honeywell-style units.
• Simple installation: Customers reported easy fastening with included screws and fast coverage of imperfections, which speeds up retrofit work.
• Neutral finish: The white plates blend with many interiors so the finished installation looks discreet and consistent.

Who It's For

This kit is best for homeowners, landlords, and HVAC installers who are replacing older landscape-style thermostats with modern T-Series models and want a quick cosmetic fix. It is particularly handy when the old thermostat left uneven paint or holes that would otherwise need drywall repair.

It is not intended for users who require specialized wiring components, as wiring parts are not included, nor for those who need custom-colored trim; painters or custom finishers may prefer a different solution if exact color matching or decorative trim is required.

Pros & Cons

Pros

• Fits a wide range of T-Series thermostats and reliably covers wall imperfections.
• Includes adaptors and screws so most installs need no extra parts.
• Sturdy construction and good coverage give a tidy, professional look.

Cons

• Wiring components are not included, so additional parts may be required for complex installs.

Specifications

Product type	Large cover plate and electrical box adaptor kit
Plate dimensions	155 x 155 x 6.5 mm (6.1 x 6.1 x 0.26 in)
Package contents	4 adaptors, 4 cover plates, 8 mounting screws
Compatibility	T-Series thermostats: T1, T2, T3, T4, T5, T6Pro, T9, T10
Mounting	Mounts to single or double gang electrical box
Wiring	Wiring components not included

Our Verdict

The THP2400A1080 cover plate kit is a practical, cost-effective choice for anyone swapping to a T-Series thermostat who wants to hide wall damage without drywall work. It includes the adaptors and screws needed for most retrofit installs, fits the common T-Series models, and delivers a neat final appearance, making it good value for routine thermostat upgrades.

Frequently Asked Questions

Will this fit my T9 thermostat?
Yes, the kit is explicitly compatible with the T9 and other T-Series models listed, and customers report a snug fit with T9 units.

Does the kit include wiring or terminals?
No, wiring components are not included; the kit supplies adaptors, cover plates and mounting screws only.

Can it hide large drywall damage?
The 155 x 155 mm plate covers most thermostat cutouts and surrounding unpainted areas, but very large or irregular wall damage may still require patching.