WiFi and Bluetooth in one module
Out of the box, every Thermostatless module talks to your home WiFi and exposes a Bluetooth fallback for direct control when the internet is down.
Version 1 · Basic
The thermostat without the thermostat.
Thermostatless is an HVAC smart control module that wires straight into your air handler and replaces the wall thermostat with your phone, your laptop, or any browser. Control heat, fan, and schedules from anywhere — no panel on the wall, no batteries to change, no gateway hub to babysit.
$249single-stage HVAC, R/C/Y/W/G
What you get
Thermostatless replaces a conventional 24V thermostat for single-stage heat + fan systems. The module sits next to the air handler, switches the relays, reads room temperature, and streams state to every client in real time.
Same dashboard, every device
A single React Native app for iOS and Android plus a web dashboard for any browser. Real-time updates over the same channel for everyone in the house.
Scheduling and hold modes
Set weekly schedules with separate heat and cool setpoints. Hold pauses the schedule for parties, sick days, or vacations until you cancel.
Condensate-safety float input
A dedicated Float In / Float Out terminal pair lets you wire a standard condensate overflow float switch. The module shuts the call for cool when the pan fills.
Direct temperature sensing
Wires a 10k NTC thermistor straight into the Temp +/- terminals. No companion sensor on the wall, no batteries, no extra mesh.
No cloud lock-in
The module is open-source firmware on top of an ESP32-S3. Run the included backend on your hardware, or use the hosted Firebase deploy. The hardware is yours.
Specs
HVAC terminals
- R
- 24 VAC hot from transformer
- C
- 24 VAC common
- Y
- Cool / compressor call
- W
- Heat call
- G
- Fan call
Sensor terminals
- Float In / Float Out
- Condensate overflow float switch (normally closed)
- Temp + / Temp −
- 10k NTC thermistor for room temperature
Modes and indicators
- Mode switch
- OFF · HEAT · FAN
- Power LED
- Green · 24 VAC present
- WiFi LED
- Blue · cloud link
- Bluetooth LED
- Blue · BLE companion
- Safety LED
- Red · condensate float tripped
- Pair button
- BLE provisioning
Compatibility
- Systems
- Single-stage heat + fan (gas, electric, hydronic) with conventional R/C/Y/W/G wiring
- Power
- 24 VAC from existing HVAC transformer
- Connectivity
- 2.4 GHz Wi-Fi · Bluetooth Low Energy 5
- Brain
- ESP32-S3 (open-source firmware in this repo)
Already have a module?
Open the dashboard to pair, schedule, and control every Thermostatless module on your account from one place.
Open dashboard