Water Heaters

Water Heaters

The Home Assistant implementation of a water heater works pretty well for pool heaters. There are a couple of things I've done to improve how the base entity works that might be helpful to others.

Recommended Dashboard Card Block

There are a couple of great cards which will give you a nice look and control for your Water Heater. (Note that if you have your Home Assistant set to metric, your water heater will be in Celcius for the time being - the water heater entity in Home Assistant doesn't yet support custom units of measure).

You will need two custom cards from the HACS repository for this to work:

• custom:water-heater-card
• custom:button-card

Then the following YAML will give you the card shown above:

cards:
  - entity: water_heater.POOL_HEATER_ENTITY
    name: Pool Heater
    sensors:
      - entity: sensor.POOL_WATER_TEMP_SENSOR_ENTITY
        name: Water Temperature
      - entity: sensor.POOL_AIR_TEMP_SENSOR_ENTITY
        name: Air Temperature
      - entity: water_heater.POOL_HEATER_ENTITY
        name: Heater Running
      - attribute: operation_mode
        entity: water_heater.POOL_HEATER_ENTITY
        name: Operating Mode
    type: custom:water-heater-card
  - cards:
      - icon: mdi:fire
        layout: icon_name_state2nd
        name: 'Heater Mode:'
        show_label: true
        state:
          - icon: mdi:toggle-switch
            label: 'On'
            operator: template
            value: |
              [[[
                return states['water_heater.POOL_HEATER_ENTITY'].attributes.operation_mode == 'on';
              ]]]
          - icon: mdi:toggle-switch-off
            label: 'Off'
            operator: template
            value: |
              [[[
                return states['water_heater.POOL_HEATER_ENTITY'].attributes.operation_mode == 'off';
              ]]]
        tap_action:
          action: call-service
          service: water_heater.set_operation_mode
          service_data:
            entity_id: water_heater.POOL_HEATER_ENTITY
            operation_mode: |
              [[[
                if (states['water_heater.POOL_HEATER_ENTITY'].attributes.operation_mode == 'on')
                  return "off";
                else
                  return "on";
              ]]]
                  
        type: custom:button-card
    type: horizontal-stack
type: vertical-stack

Recommended Custom Sensor - Pool Heater Today

I like to know how long my heater has run for gas/energy tracking purposes (and to shame myself into putting on my solar blanket more often). To do that I created a custom sensor using the history_stats platform that tracks that usage.

To create the sensor, you will need to edit your configuration.yaml file and add the following (add to your existing sensor: section if you already have one):

sensor:
  - platform: history_stats
    name: Pool Heater Today
    entity_id: water_heater.POOL_HEATER_ENTITY
    state: "on"
    type: time
    start: "{{ now().replace(hour=0, minute=0, second=0) }}"
    end: "{{ now() }}"

Displaying the Pool Heater History

Of course you'll want to visualize the data you get out of the pool heater history sensor you just created, so I use a history-graph card in my dashboard:

entities:
  - entity: sensor.pool_heater_today
hours_to_show: 168
refresh_interval: 0
type: history-graph