Meross
Meross Smart Thermostat MTS200 (Boiler)
- Wi-Fi
Verified September 2026
At around two-thirds the price of the Netatmo Smart Thermostat, and a shade under the Hive Mini, this is the budget pick for combi boilers and hydronic underfloor heating — if you're happy with local Wi-Fi over cloud. The meross_lan HACS integration talks to it over plain HTTP on your own network, so there's no subscription or dependency on Meross's servers. Installation is the catch: it needs mains live/neutral plus a volt-free contact wired into the boiler's controls, ruling out a battery stat's plug-and-play setup and often meaning an electrician for anything beyond a straightforward combi. Electric heating and hot-water-only channels aren't supported — check you have the boiler variant (MTS200BHK).
In Home Assistant
| Control | Type | What it does |
|---|---|---|
| Climate | Climate | Heat/cool/off hvac_mode plus target temperature; running state reflects the MTS200's own reported relay status rather than being inferred from setpoint vs current temperature. |
| Preset setpoints | Number (per preset) | Each onboard schedule preset gets its own adjustable setpoint entity rather than a single climate preset list. |
| Temperature calibration | Number | Corrects the internal sensor reading against a reference thermometer — worth setting once at install since this same sensor drives the boiler relay logic, not just the display. |
| Switching differential | Number | Sets how many degrees below setpoint the internal sensor must drop before the relay calls for heat again; widening it on a slow hydronic UFH loop reduces short-cycling. |
| Temperature / humidity | Sensor | Onboard readings published as standalone sensor entities distinct from the climate entity's own temperature. |
Beyond hvac_mode/target_temperature, meross_lan surfaces the running heat/idle state from the MTS200's own relay status rather than deriving it from setpoint-vs-current-temperature, so automations can watch for the boiler genuinely being called rather than just target being unmet. Each onboard schedule preset (comfort/sleep/away/custom) is exposed as its own adjustable setpoint entity instead of a single HA preset list. A calibration/offset entity lets you correct the internal sensor against a reference thermometer, and a separate switching-differential setting controls how many degrees of overshoot the relay tolerates before cutting out, worth widening on a slow-responding hydronic UFH loop to cut short-cycling. One recurring firmware quirk: the display brightness entities reset to a fixed value regardless of what's written, so treat that control as unreliable rather than a real dimmer.
Specs
- app
- Meross app — iOS 13.0+, Android 6.0+
- wifi
- IEEE 802.11 b/g/n, 2.4GHz only
- model
- MTS200BHK
- display
- Backlit LED display behind a glass panel (no touchscreen)
- dimensions
- 86 x 86 x 42 mm
- power source
- Mains-wired, 100-250V~ 50/60Hz
- boiler interface
- Volt-free relay (combi/water systems)
- temperature range
- 5-35°C control range, ±0.5°C accuracy
- operating temperature
- 0-40°C ambient