Intex Spa Docs

External Filter Coordination

Understanding the Steinbach dependency and how to coordinate with Intex heating.

The Problem

Your Steinbach Comfort 50 external filter connects via Y-connector. When the Steinbach is OFF, not enough water flows through the Intex system, triggering E90 (low water flow). The Steinbach must be running for the Intex to work.

The Dependency

Steinbach ON → Intex Works

When the external filter is running, water flows through the system. The Intex sees adequate flow and operates normally.

Steinbach OFF → Intex Errors

Without the external filter running, there's not enough flow. The Intex triggers E90 and refuses to heat.

Key Understanding

  • Steinbach can run alone — just filters the water, no dependency on Intex
  • Intex cannot run alone — needs Steinbach running first to provide flow
  • Steinbach is the prerequisite — always ensure it's running before starting Intex heater

Steinbach Control Limitation

Physical Buttons Required

The Steinbach Comfort 50 has TIMER and ON/OFF buttons. It doesn't auto-start when powered — you must press the button. Timer options: 2h, 4h, 8h, 16h, 24h.

Current workaround: Set Steinbach to 24h timer mode so it runs continuously. This ensures Intex always has flow available.

Coordination Strategies

1

Simple: Steinbach Runs 24/7 (Current)

Keep the Steinbach on 24h timer mode. It runs continuously, so Intex always has flow. The ESP32 controller can freely control Intex heating anytime.

Pros: Simple, reliable, no extra hardware

Cons: Steinbach uses power 24/7 (~50W)

2

Advanced: SwitchBot Button Pusher

Add a SwitchBot Bot (~$30) to press the Steinbach ON/OFF button remotely. Integrate with Home Assistant via SwitchBot Hub or Bluetooth proxy.

Pros: Can start/stop Steinbach on demand, save energy

Cons: Extra hardware, more complexity

3

DIY: Modify Steinbach Controller

Solder wires across the ON/OFF button contacts, connect to a relay controlled by ESP32 or Home Assistant. Simulates button press.

Pros: Full control, no extra hardware cost

Cons: Voids warranty, requires soldering

Home Assistant Automations

Strategy 1: Steinbach Always On

With Steinbach running 24/7, your automations only need to control the Intex side:

automation:
  - alias: "Spa - Heat Before Evening Use"
    trigger:
      - platform: time
        at: "16:00:00"
    condition:
      - condition: time
        weekday: [fri, sat, sun]
    action:
      - service: climate.set_temperature
        entity_id: climate.intex_spa_water_temperature
        data:
          temperature: 38
      - service: switch.turn_on
        entity_id: switch.intex_spa_heater

  - alias: "Spa - Notify on Error"
    trigger:
      - platform: state
        entity_id: sensor.intex_spa_error_code
    condition:
      - condition: template
        value_template: "{{ states('sensor.intex_spa_error_code') != '' }}"
    action:
      - service: notify.mobile_app
        data:
          title: "Spa Error"
          message: "Error code: {{ states('sensor.intex_spa_error_code') }}"

Strategy 2: With SwitchBot Control

If you add a SwitchBot to control Steinbach, ensure it's running before heating:

automation:
  - alias: "Spa - Start Steinbach Before Heating"
    trigger:
      - platform: state
        entity_id: input_boolean.spa_heat_requested
        to: "on"
    action:
      # Press Steinbach ON button via SwitchBot
      - service: button.press
        entity_id: button.switchbot_steinbach_on
      # Wait for flow to stabilize
      - delay: "00:00:30"
      # Now start Intex heater
      - service: switch.turn_on
        entity_id: switch.intex_spa_heater

  - alias: "Spa - Stop Heating on Steinbach Off"
    trigger:
      - platform: state
        entity_id: binary_sensor.steinbach_running
        to: "off"
    action:
      - service: switch.turn_off
        entity_id: switch.intex_spa_heater
      - service: notify.mobile_app
        data:
          title: "Spa Warning"
          message: "Steinbach stopped - Intex heater disabled to prevent E90"

Monitoring Steinbach Status

Even with Strategy 1 (Steinbach 24/7), it's useful to know if the Steinbach is actually running. Options:

  • Smart plug with power monitoring — if power draw > 30W, it's running
  • Vibration sensor — attached to pump housing, detects when running
  • Flow sensor — inline sensor in Y-connector tubing

Recommended Approach

Start Simple

  1. Keep Steinbach on 24h timer
  2. Build the Intex ESP32 controller
  3. Control Intex heating via Home Assistant
  4. Add error notifications

Upgrade Later (Optional)

  1. Add smart plug with power monitoring
  2. Add SwitchBot for Steinbach control
  3. Create coordinated automations
  4. Save energy by not running 24/7

The ESP32 controller gives you visibility and control over the Intex side. For full Steinbach control, see the Steinbach Modification guide — replace the timer board with a Shelly for WiFi control.