You already have electric roller shutters that go up and down via the wall switch. Seeing Smart Home capabilities, you wonder: "How great would it be to close them from my bed with my phone or tell Alexa to open them?"
The first thought - replacing the motors - is expensive and unnecessary. The solution costs just €15–25 per shutter and is called a Smart Relay. You change absolutely nothing on the window or motor.
It is a tiny electronic board (roughly matchbox-sized) with a built-in Wi-Fi receiver. Many brands exist (Sonoff, Tuya), but the "king" of the roller-shutter category is the European Shelly (Shelly 2.5 or the newer Shelly Plus 2PM). Shelly is a Bulgarian company with European manufacturing, CE certification and thousands of positive reviews from DIY communities worldwide.
The device hides inside the wall, behind the existing switch. It sits between the switch and the motor cable. It is invisible, changes no aesthetics - and keeps the physical switch fully functional. The relay also features a built-in power meter that records the energy consumption of every movement in real time.
Why is this "hack" the No.1 choice worldwide for upgrading existing shutters?
For roughly €20 you install the "brain" into the system. You keep your old, reliable motor as is. No new motor purchase, no tearing open shutter boxes, no rewiring at the motor end. Installation happens exclusively behind the switch.
This is critical. The physical switch works normally. Grandparents or guests open the shutter by hand, while you control it simultaneously from your phone. If Wi-Fi goes down, the switch operates autonomously - zero dependency.
It connects directly to your router. Download the free app, pair in 2 minutes and you are done. No central "brain" needed - reducing cost and complexity.
Direct integration with Google Home, Amazon Alexa and Apple HomeKit (via Matter). You can request percentages: "Alexa, set living room blind to 50%". Create "Goodnight" / "Good Morning" scenes exactly like with dedicated Wi-Fi motors.
Before rushing to buy relays for the entire house, open a switch plate and check two critical prerequisites:
The relay needs permanent power to stay connected to Wi-Fi. Inside the switch box there must be (besides the Live) a Neutral wire (usually blue). If there isn't one, an electrician can pull one from the nearest junction box - a 10-minute job at minimal cost.
The relays are small, but older switch boxes are often shallow. Ideally you need deep boxes (60 mm) so the switch, relay and cables fit comfortably without being squeezed. During electrical refits, always request deep boxes at every shutter point.
Shelly regularly releases firmware updates that install wirelessly (Over-The-Air) through the app. Each update improves security, fixes bugs and adds new features - such as Matter support and energy statistics. You never need to buy a new device to enjoy the latest capabilities.
Make sure your motor does not exceed the 10 A rating (~2,300 W) of the Shelly Plus 2PM. For most residential shutters (150–300 W) there is a huge margin. If you have a heavy-duty patio motor, ask for an industrial-grade relay with a matching output current.
⚠️ ELECTROCUTION RISK: Installation involves working with 230 V mains. If you have no electrical knowledge, do not attempt this yourself. Call a licensed electrician. The description below is purely informational.
Switch off the main breaker or the relevant circuit breaker. Confirm with a test screwdriver that there is no power. Remove the switch from the wall.
L (Line): Live. N (Neutral): Neutral. O1 & O2: Motor cables (Up / Down). S1 & S2: Wall switch button wires. The relay goes into the box and the switch is screwed back in place.
Power back on, connect via the app, press "Calibration". The relay runs the shutter up and down on its own, measures power consumption (watts) and "learns" the top and bottom limits. From now on it accepts percentages: open to 30%, 70%, 100%.
💡 Summary: The smart relay is the "Trojan Horse" of Smart Home technology. It brings full control to your old shutters at minimal cost, with no aesthetic changes and without sacrificing the manual wall switch.
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