The short version: Read the model number carefully before buying. The MTS100 and MTS150 are Meross’s smart thermostatic radiator valve (TRV) line — a battery-powered smart valve that screws onto an existing radiator, not a wall thermostat for a furnace or ducted forced-air system. If you have hydronic radiator heat (common in older homes, condos, and apartment buildings, especially in the Northeast US), it’s a genuinely useful, affordable smart-heating upgrade. If you have a standard North American forced-air furnace, this isn’t the right product — Meross sells a separate wall-mount thermostat line for that (C-wire required), and it carries different model numbers.

Who It’s For

The MTS100/MTS150 fits:
– Homes with hydronic radiators using the common M30 x 1.5mm valve thread (check your existing radiator valve before buying)
– Renters or condo owners who can’t rewire a furnace but want per-room smart heating control on individual radiators
– Budget buyers who want basic smart scheduling on radiator heat without a full system replacement

It does not fit forced-air/ducted homes — this isn’t a furnace thermostat. If that’s your setup, see our reviews of Sensi, ecobee, or Honeywell wall thermostats instead, or look at Meross’s separate wall-thermostat product line, which requires a C-wire and different wiring than a radiator valve.

The MTS150 adds Apple HomeKit support over the base MTS100, which supports Alexa, Google Assistant, and SmartThings only.

Design & Build

The valve has a minimalist cylindrical shape, visually similar in concept to Tado’s radiator valve, with three touch-sensitive buttons for on-device control. One noted design quirk from independent reviews: the display only lights up after you press a button, and the touch-sensitive buttons themselves can be a little fussy to hit accurately. It runs on 2 AA batteries (not included in some listings — check before buying).

Setup & Compatibility

A Meross hub is required for the MTS100 to connect to Wi-Fi and be controlled remotely or via voice assistant — factor the hub cost into your total price if you don’t already own one. One hub supports multiple valves (reviewers cite support for well over a dozen), so the cost amortizes if you’re outfitting several radiators.

Installation is a physical swap: unscrew your existing radiator valve head, screw on the Meross valve. No electrical wiring involved. The valve includes multiple adapter fittings for different radiator valve thread sizes, though M30 x 1.5mm is the most common. It’s worth confirming your radiator’s thread size before ordering, since not every radiator is compatible out of the box.

A useful feature: open-window detection, which automatically pauses heating if it senses a rapid temperature drop consistent with an open window, a genuinely practical energy-saving touch for radiator heat.

App & Ecosystem

The Meross app handles scheduling and remote control, with independent European reviewers describing the setup process as reasonably smooth, though some app translation and polish issues have been noted.

Ecosystem support:
– MTS100: Amazon Alexa, Google Assistant, SmartThings (via hub)
– MTS150: Adds Apple HomeKit support

Price & Value

Item Price (USD)
Meross MTS100/MTS150 (per valve) ~$60-100
Meross hub (if not already owned) Sold separately, factor into total cost

Pricing is genuinely low for smart heating control, especially per-radiator if you’re outfitting a home with several units off a shared hub. Available through Amazon.com.

Sourcing note: Independent English-language, US-market review coverage of this specific model line is thin — most detailed testing we found comes from German-language smart home outlets and buyer feedback on Amazon-style retail listings rather than major US publications like Wirecutter or CNET. Treat pros/cons here as directionally reliable but not as deeply verified as our reviews of higher-profile brands.

Pros & Cons

Pros:
– Genuinely useful for hydronic radiator heat, an underserved category among mainstream smart thermostat brands
– Low per-unit price, especially when scaling across multiple radiators on one hub
– No electrical wiring required — physical valve swap only
– Open-window detection is a practical touch
– MTS150 adds HomeKit support

Cons:
– Does not work with forced-air/ducted systems — read the model description carefully before buying
– Requires a separate hub purchase for full smart functionality
– Touch-sensitive buttons and non-illuminated display draw some criticism
– Limited independent US-market review coverage compared to major thermostat brands
– Batteries not always included

Meross MTS100 vs MTS150 vs other smart radiator valves: features, price, and hub requirements compared

The Recommendation

Buy the Meross MTS100/MTS150 only if you have hydronic radiator heat with a compatible valve thread — it’s a legitimately affordable way to add smart scheduling to radiator-based heating. Do not buy this if you have a standard forced-air furnace; it will not work on that kind of system. For forced-air homes, see our reviews of Sensi, Honeywell, or ecobee wall thermostats.

Frequently Asked Questions

Does the Meross MTS100/MTS150 work with a forced-air furnace?
No. This is a smart radiator valve for hydronic (water/steam radiator) heating, not a wall thermostat for a ducted forced-air furnace. If you have a furnace, look at Meross’s separate wall-mount thermostat line, or a dedicated furnace thermostat like Sensi or Honeywell.

Do I need a hub for the Meross MTS100?
Yes, for full Wi-Fi and voice assistant functionality. Without a hub, the valve can generally still be controlled locally but loses remote/app access.

What’s the difference between MTS100 and MTS150?
The MTS150 adds Apple HomeKit support. The MTS100 covers Alexa, Google Assistant, and SmartThings but not HomeKit.

Will the Meross valve fit my radiator?
It’s built around the common M30 x 1.5mm thread with included adapters for some other sizes. Check your existing radiator valve’s thread before ordering.

Is there good independent review data for this product?
Coverage is thinner than for mainstream US thermostat brands — most detailed testing comes from European smart-home outlets. Treat this as a lower-information purchase and check current buyer ratings on the retailer listing before ordering.