Installing Your Stelpro Ki Smart Thermostat

Intermediate 30-45 minutes

What You'll Need

  • Stelpro Ki Smart Thermostat
  • Stelpro Maestro/Ki app (iOS or Android)
  • 2.4GHz Wi-Fi network
  • Electric heating system (120V or 240V depending on model)
  • Wire strippers
  • Wire nuts or push-in connectors
  • Voltage tester

Before You Start

The Stelpro Ki is a line-voltage thermostat for electric heating systems. It directly switches 120V or 240V power to baseboard heaters, convectors, and fan-forced heaters. Like other line-voltage thermostats, it carries dangerous voltage levels. If you are not comfortable working with electrical wiring, have a licensed electrician handle the installation.

Voltage and Load Verification

The Stelpro Ki comes in 120V and 240V versions. Make sure you have the correct model for your system. Check the breaker that feeds your heater: single-pole is usually 120V, double-pole is usually 240V. Also verify the combined wattage of heaters on the circuit does not exceed the thermostat's rated capacity (typically 3000W at 240V or 1500W at 120V). Overloading the thermostat is a fire hazard.

Step-by-Step Installation

  1. Turn off power at the breaker. Use a voltage tester to confirm the wires are dead.
  2. Remove the old thermostat. Identify and label the LINE wires (from the panel) and LOAD wires (to the heater). On 240V circuits, both conductors are hot.
  3. Connect wiring to the Stelpro Ki:
    • Connect LINE wires to the LINE terminals
    • Connect LOAD wires to the LOAD terminals
    • Follow the wiring diagram included with the thermostat
    • Secure all connections with wire nuts or push-in connectors
  4. Mount the thermostat to the electrical box.
  5. Restore power at the breaker.
  6. Download the Stelpro app, create an account, and add the thermostat. Connect to your 2.4GHz Wi-Fi network and configure your preferences.

System Compatibility Notes

The Stelpro Ki is designed specifically for resistive electric heating loads, including baseboard heaters, wall convectors, and fan-forced heaters. It works best with Stelpro's own heater lineup but is compatible with other brands as well. The thermostat does not work with central HVAC systems, heat pumps, or any 24V equipment. If your heater has a built-in thermostat, set the heater's thermostat to maximum and let the Stelpro Ki handle temperature regulation.

Smart Home Integration

The Stelpro Ki works with Amazon Alexa, Google Assistant, and Apple HomeKit. HomeKit support allows you to add the thermostat to the Apple Home app, use Siri for voice control, and create automations with other HomeKit accessories. Alexa and Google integration provides standard voice commands for temperature adjustments. The Stelpro app supports multi-zone management, letting you control all your Stelpro thermostats from one interface. Home Assistant users can integrate via the HomeKit controller or the Stelpro Maestro platform.

Energy Saving Features

  • Multi-zone scheduling lets you program each room's thermostat independently, heating only where and when you need it
  • Energy monitoring tracks power consumption per thermostat, so you know exactly what each room costs to heat
  • Weather-adaptive control adjusts heating behavior based on outdoor temperature forecasts, reducing energy use on milder days
  • Eco mode applies a setback temperature across all zones with a single tap
  • Away mode reduces heating to a minimum maintenance level when you leave the house
  • Smart grouping lets you manage related rooms together (upstairs, downstairs, bedrooms) for coordinated temperature control

Troubleshooting

  • Safety first: Always turn off the breaker and verify with a voltage tester before touching any wires. The Stelpro Ki carries line voltage (120V or 240V) and is not a safe device to work on while live.
  • Heater not turning on: Check that LINE and LOAD wires are on the correct terminals. Reversing them is a common mistake. Use a voltage tester to confirm power reaches the LINE terminals when the breaker is on.
  • Won't connect to Wi-Fi: The Stelpro Ki requires a 2.4GHz network. If you have a combined dual-band router, try splitting the bands for setup. Ensure the thermostat is within range of your router or a mesh access point.
  • Temperature reading is too high: If the thermostat is mounted on the same wall as (or directly above) a baseboard heater, rising heat can cause it to read higher than the actual room temperature. The Stelpro app allows a temperature offset adjustment to compensate.
  • Breaker trips on heat call: The connected heater load may exceed the thermostat's capacity. Add up the wattage of all heaters on the circuit and compare against the thermostat's rating. For loads that exceed the limit, install a contactor or relay between the thermostat and the heater circuit.
  • Factory reset: Reset through the Stelpro app or by following the manual reset procedure on the thermostat hardware.

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