eSpa

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ESPySpa Firmware ​

ESPySpa is the original eSpa firmware, built on the Arduino framework using PlatformIO. It's the most established firmware option, with a large user base and proven track record across many spa installations.

Why Choose ESPySpa? ​

  • Fully standalone — control your spa entirely from the built-in web interface, with no external software required. Change temperature, control pumps, configure schedules — all from your browser.
  • Battle-tested — ESPySpa has been in use for years across many installations. It's well-understood, stable, and has a large community of users in the Discord.
  • Web flash tool — first-time setup is simple via flash.espa.diy using just a USB cable and a Chrome browser. No development environment needed.
  • Remote debugging — built-in telnet-based remote debugging (via the RemoteDebug library) lets you diagnose issues without a USB connection.

Features ​

  • Web interface: Full control and configuration — temperature, pumps, lights, modes, timers, filtration — all from your browser.
  • MQTT with HA auto-discovery: Publishes all entities to MQTT with Home Assistant auto-discovery, so your spa appears automatically in HA.
  • Temperature control: Automatic heater management to maintain your setpoint.
  • Pump control: Up to 5 pumps with variable speed settings.
  • Light control: On/off with colour modes and speed selection.
  • Blower control: Variable speed blower support.
  • Energy monitoring: Mains voltage, current, power, and total energy consumption (kWh).
  • Sleep timers: Two configurable sleep timer schedules.
  • Filtration control: Adjustable filtration block duration.
  • Lock mode: Spa lock mode control.
  • Spa mode: Operating mode selection (e.g. Normal, Economy, Away).
  • Heat pump support: Ambient/condensor temperatures, heat pump mode, and auxiliary heat element status (where applicable).
  • OTA updates: Over-the-air firmware updates from the web interface.
  • Remote debugging: Telnet-based debug access for troubleshooting without USB.
  • mDNS: Discover your eSpa on the local network by hostname.

Source Code ​

The ESPySpa firmware is open source and available on GitHub.

Next Steps ​