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Demand response: grid events on your Cala

Choose how much your Cala takes part in utility grid events, and what to do when one is running.

Updated October 31, 2026

With demand response, your utility can ask your Cala to use less electricity when the grid is busy, or more when power is plentiful. Cala works these requests into its heating plan. This helps your regional grid, and some utility programs pay incentives for taking part.

How it works

Your utility sends grid events to your Cala through a CTA-2045 module plugged into the heater. Availability varies by region. You choose how much your Cala takes part, and you can opt out of any single event.

Choose how much you take part

  1. On your Cala's screen, press Down until SETTINGS is highlighted, then press Select.

  2. Press Down until ADVANCED is highlighted, then press Select.

  3. Press Down until DEMAND RESPONSE is highlighted, then press Select. The DEMAND RESPONSE screen opens with a slider from Don't participate to Maximum.

    DEMAND RESPONSE screen with the slider at 5, between Don't participate (0) and Maximum (10)
    The slider starts in the middle.

  4. Press Up to move the slider toward Don't participate, or Down to move it toward Maximum. Higher means more energy savings; lower means less impact on your hot water. It starts in the middle.

  5. Press Select to save. The Demand Response Options screen opens.

Opt in or out

The Demand Response Options screen shows whether your Cala is taking part: STATUS: OPTED IN or STATUS: OPTED OUT.

  1. Press Up or Down until the status button is highlighted.

    Demand Response Options screen with STATUS: OPTED IN highlighted and LEVELS below
    STATUS: OPTED IN means your Cala takes part in grid events.

  2. Press Select. The status switches between STATUS: OPTED IN and STATUS: OPTED OUT.

To change the slider again, highlight LEVELS and press Select. Press Back to return to ADVANCED.

During a grid event

When a grid event starts, a banner on your Cala's Home screen says what kind it is:

  • DEMAND RESPONSE: SHED: your Cala heats more slowly during the event.
  • DEMAND RESPONSE: PEAK: your Cala heats much more slowly during the event.
  • DEMAND RESPONSE: EMERGENCY: your Cala doesn't heat during the event.
  • DEMAND RESPONSE: LOAD UP: your Cala heats more than normal, storing energy as hot water for later.
Home screen with the DEMAND RESPONSE: SHED banner, the Shed Event explanation and OVERRIDE GRID EVENT highlighted
During a Shed event the boost button becomes OVERRIDE GRID EVENT.

Opt out of one event

Need full heating right now, say for guests? You can skip the event that's running.

  1. On your Cala's Home screen, press Up or Down until OVERRIDE GRID EVENT is highlighted.

  2. Press Select. The event explanation disappears and the button goes back to BOOST HEAT. Your Cala heats normally again.