Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US) vs Sensi Smart Thermostat ST55
These are side-by-side facts taken from each product guide: published specifications, strengths and caveats as their sources state them. This page is not a test, a ranking or a verdict about which model is better.
Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US)
120V or 240V electric baseboard, fan-forced convector and radiant ceiling heat in a standard gang box
A line-voltage smart thermostat for electric resistance heat, rated 1,900 W at 120 VAC and 3,800 W at 240 VAC with a 16 A maximum and a 250 W minimum load. It measures current and voltage for real energy reports, runs on 2.4 GHz Wi-Fi with no hub, works with Alexa, Google Home and Apple Home, and carries a five-year warranty.
Published specifications
- Maker: electric baseboard, fan-forced convector and radiant ceiling heating only
- Maker: NOT compatible with low-voltage 24V, millivolt (gas fireplaces), central hydronic or electric in-floor
- Maker: 1,900 W at 120 VAC; 3,800 W at 240 VAC, 16 A max; minimum load 250 W
- Maker: standard gang box, 20 A breaker, neutral or L2; wiring setups V-L-L or V-L-N
- Maker: Wi-Fi 2.4 GHz 802.11 b/g/n plus Bluetooth LE, no hub; Alexa, Google Home and Apple Home
- Maker: temperature +/-0.5F, humidity +/-2%, light, proximity, current and voltage sensing; 5-year warranty
Strengths
- One of the few smart thermostats that actually runs 120V and 240V electric resistance heat
- Built-in current and voltage sensing gives measured energy reports, not estimates, with no subscription
- Five-year warranty and a published spec sheet whose SKU matches the listing's part number exactly
Caveats
- Useless on any 24V system: no furnace, heat pump, central boiler or millivolt fireplace support
- Load limits cut both ways: 250 W minimum and 1,900 W or 3,800 W maximum depending on voltage
- The listing says it will not work on two-wire installations while the maker's sheet lists a line-voltage 2-wire setup
Read the full Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US) guide
Sensi Smart Thermostat ST55
Conventional or heat pump systems up to two stages, on a 2.4GHz network, in the old thermostat's footprint
A button-and-LED smart thermostat whose manual configures one or two stages of conventional cooling, gas or electric heat, and one or two stage heat pumps, with a built-in RC/RH jumper you clip for two-transformer systems. Batteries are included, but the manual says a common wire is required on heat-only, cool-only and heat pump systems.
Published specifications
- Manual: terminals RH, RC, C, Y, Y2, W/E, W2, G, O/B and a non-functional L
- Manual: configures AC1/AC2 cooling, GA1/GA2 gas, EL1/EL2 electric, HP1/HP2 heat pump, fan-only and no-cooling
- Manual: common connection required on heat-only, cool-only or heat pump systems; listing says C wire not needed in most applications
- Manual: two-transformer systems supported by clipping the internal RC/RH jumper above the battery compartment
- Manual: Sensi app and Sensi account required to install; router must be a 2.4GHz network
- Warranty: three-year retail limited warranty; five years only for PRO models installed by a PRO contractor
Strengths
- Handles two-stage heat and two-stage cool, heat pumps and two-transformer systems at an entry price
- Fits the old thermostat's footprint with buttons, a built-in level, wire labels and AA batteries in the box
- Both the installation guide and the full warranty text are published on the listing itself
Caveats
- The manual requires a common wire on heat-only, cool-only and heat pump systems, and no adapter is included
- 2.4GHz Wi-Fi only, and the Sensi app plus a Sensi account are required to install it at all
- Warranty remedy is replacement only, is void if you attempt a repair, and excludes commercial installations
How to choose between them
Choose the Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US) if your situation matches: 120V or 240V electric baseboard, fan-forced convector and radiant ceiling heat in a standard gang box. Its main caveat: Useless on any 24V system: no furnace, heat pump, central boiler or millivolt fireplace support.
Choose the Sensi Smart Thermostat ST55 if your situation matches: Conventional or heat pump systems up to two stages, on a 2.4GHz network, in the old thermostat's footprint. Its main caveat: The manual requires a common wire on heat-only, cool-only and heat pump systems, and no adapter is included.
Both entries repeat what each guide records. Confirm the model, included parts and availability on the current listing before ordering.
Primary sources
- Mysa for Baseboard V2 product spec sheet (maker PDF), SKU BB.2.0.01.NA-US Source for Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US)
- Mysa product page for Mysa for Electric Baseboard Heaters V2 Source for Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US)
- Mysa compatibility checker, named on the spec sheet and the product page Source for Mysa Smart Thermostat V2 for Electric Baseboard Heaters (BB.2.0.01.NA-US)
- Sensi Wi-Fi Programmable Thermostat installation guide supplied with the Amazon listing (Emerson) Source for Sensi Smart Thermostat ST55
- Emerson Thermostat Limited Warranty supplied with the Amazon listing Source for Sensi Smart Thermostat ST55
- Sensi (Copeland) manuals index for the Sensi smart thermostat Source for Sensi Smart Thermostat ST55
Primary sources checked .