Shelly Plus 2PM Review: Control Two Devices Independently

Overview & Gen2 Upgrade

The Shelly Plus 2PM is the second-generation successor to the original Shelly 2.5, and it's a significant upgrade in almost every way. The "Plus" designation marks Gen2 hardware — a new ARM-based processor (replacing the ESP8266/ESP32 of Gen1), improved Wi-Fi reliability, better thermals, and a completely redesigned firmware with a modern REST API.

The core proposition remains the same: a dual-channel smart relay that fits inside a back box and can independently control two separate circuits — or operate in roller/shutter mode to control a single motorised blind or curtain. Add power monitoring on both channels, and you have one of the most capable smart relays available at this price point.

Hardware & Specs

The Shelly Plus 2PM measures 52mm × 42mm × 22mm — slightly larger than the Shelly 1PM, but still designed to fit in standard back boxes. It requires a neutral wire for operation, which is an important consideration during installation. Both channels support up to 16A each (25A total device limit), making them suitable for lighting circuits, fan motors, and small appliance circuits.

The Gen2 hardware includes:

• ARM Cortex-M3 processor (more powerful and efficient than ESP8266)
• 802.11 b/g/n Wi-Fi with improved antenna design for better range
• Two relay outputs, each with independent power monitoring
• Two external input terminals (for wall switches or push buttons)
• Bluetooth for initial setup (no need to connect to the device's own AP)
• Over-temperature protection with automatic load cutoff

The Bluetooth setup option in Gen2 is a genuine quality-of-life improvement — you can configure the device via the Shelly app over Bluetooth before it's connected to your Wi-Fi network, making initial setup faster and more reliable.

Operating Modes: Switch & Roller

The Shelly Plus 2PM operates in one of two modes, configured via the web interface or app:

Switch Mode (2 independent channels)

In switch mode, the two channels operate completely independently. Each can be wired to a different circuit — for example, Channel 1 controls a kitchen light circuit and Channel 2 controls a worktop socket circuit. Each has its own switch input, power monitoring, timers, and automation rules. This essentially gives you two Shelly 1PM devices in a single unit, making it more cost-effective and space-efficient for dual-circuit applications.

Roller/Shutter Mode (single cover entity)

In roller mode, the two channels work together to control a single motorised blind, curtain, or roller shutter. Channel 1 powers the motor in one direction (up), Channel 2 powers it in the other (down). The Shelly Plus 2PM's firmware manages safety interlocks — it's impossible for both channels to activate simultaneously, preventing motor damage.

In Home Assistant, roller mode exposes the device as a Cover entity, complete with position control (0–100%), up/down/stop commands, and position calibration. You can precisely control blind position — "set the living room blinds to 60%" — and create automations based on sun position, time of day, or temperature. This is a transformative feature for homes with motorised blinds.

Home Assistant Integration

The Shelly Plus 2PM integrates with Home Assistant via the official Shelly integration, which supports Gen2 devices natively. Discovery is automatic — once the device is on your network, it appears in Home Assistant's device registry within minutes.

In switch mode, you get:

• Two switch entities (one per channel)
• Two power sensors (real-time watts per channel)
• Two energy sensors (cumulative kWh per channel, Energy Dashboard compatible)
• Voltage, current, and temperature sensors

In roller mode, you get:

• A Cover entity with position control
• Combined power monitoring for the motor
• Position sensors

All updates are near-real-time, and all commands execute locally with sub-100ms latency. The Gen2 REST API is faster and more reliable than Gen1's CoAP-based communication, and the Shelly integration fully exploits this.

Dual Power Monitoring

Having independent power monitoring per channel is genuinely useful. With two circuits being tracked, you can monitor energy consumption from two different devices simultaneously and integrate both into Home Assistant's Energy Dashboard. For a home trying to understand and reduce energy usage, this is excellent value — you're essentially getting two energy monitors for the price of one device.

Accuracy is comparable to the Shelly 1PM — within 1–2% of calibrated reference measurements. The monitoring includes:

• Real-time power (W)
• Total energy (kWh, persistent across reboots)
• Voltage (V)
• Current (A)
• Power factor

Shelly Plus 2PM vs Shelly 1PM

The Shelly Plus 2PM costs roughly 1.5× the price of a Shelly 1PM. If you need two independent circuits in a single back box, the 2PM is obviously the better choice — it's less expensive than buying two 1PMs and takes less space. If you need roller/shutter control, the 2PM is your only Shelly option.

For single-circuit applications, the Shelly 1PM (or its Gen2 equivalent, the Shelly Plus 1PM) remains the better-value choice. The 2PM's dual-channel capability is its primary advantage.

Verdict

Buy if: You need to control two independent circuits from one back box, or you have motorised blinds/shutters to automate.

Skip if: You only need to control a single circuit — the Shelly Plus 1PM is better value.

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