Smart Wi-Fi thermostat ยท meross

meross MTS300 Smart Thermostat

Smart Wi-Fi thermostat, C adapter included

At a glance

A fit for phone control and scheduling.

Strong points
C-wire adapter included.
Weak points
Needs Wi-Fi for smart features.
Best match
Phone control and scheduling.
Connectivity
Wi-Fi
Display
LED
Power
Corded Electric
Voltage
24 V
Dimensions (seller)
0.9"D x 3.6"W x 3.6"H
Warranty
3 year.
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Updated October 2026

Will it work with your system?

Works well with

  • Phone control and scheduling
  • Systems the maker's checker confirms

Check first if you have

  • Line-voltage baseboard heat
  • Millivolt gas heaters

What it controls

The meross MTS300 Smart Thermostat is a smart Wi-Fi thermostat. Its listing doesn't spell out which heating and cooling systems it supports, so run the maker's compatibility checker before you buy.

Power is where installs stall: it needs steady power and the maker includes a C-wire adapter; its wording is "Some wiring configurations require a C wire (not included)". C-wire options.

The listing doesn't state heat pump support; if you have an O/B wire, confirm with the maker before ordering. Heat pump wiring.

Connectivity: Wi-Fi. It amazon Alexa, Android, Apple HomeKit, Google Assistant, SmartThings.

Tick your terminals in the wiring checker to see whether its maker's statements cover your system.

Also on the listing: dimensions of 0.9 in (D) x 3.6 in (W) x 3.6 in (H) and a led.

Warranty, per the listing: 3 year.

Compatibility and specs

These come from the maker's listing for this exact model; the source of each is marked. Anything the maker leaves out is marked not stated.

Model numberMTS300Retailer
Model nameMTS300Retailer
Dimensions (seller)0.9"D x 3.6"W x 3.6"HRetailer
Works withAmazon Alexa, Android, Apple HomeKit, Google Assistant, SmartThingsRetailer
Features (seller)Lockable, Low Voltage, Portable, Programmable, Temperature DisplayRetailer
ConnectivityWi-FiRetailer
PowerCorded ElectricRetailer
Voltage24 VRetailer
DisplayLEDRetailer
Mounting / installationWall MountRetailer
Warranty3 year.Retailer
C-wireSome wiring configurations require a C wire (not included)Retailer

Strong points and weak points

Strong points

  • C-wire adapter included
  • Works with Amazon Alexa, Android, Apple H

Weak points

  • Needs Wi-Fi for smart features

Wiring and install notes

  • Compatibility statements are the maker's own. Confirm with the maker's compatibility checker, turn the power off before wiring, and leave line-voltage and furnace work to a licensed electrician or HVAC technician.

Thermostats to compare it with

FAQ

Does the meross MTS300 Smart Thermostat need a C wire?
It needs steady power and the maker includes a c-wire adapter.
Does the meross MTS300 Smart Thermostat work with a heat pump?
The listing doesn't say; check the maker's compatibility checker.

Other smart thermostats with similar wiring

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Our take

A fit for phone control and scheduling.

Where to get it

The link goes to this exact model's listing. Check that the box includes the trim plate or C-wire adapter you need, and confirm your wiring with the maker's compatibility checker before you order.

Prices change often; the button shows today's price.

Each button opens this exact model. We may earn a commission on tracked links; it never changes what we publish. Disclosure