Shelly blind or curtain calibration fails

Why it happens

Quick checks first

Run these checks before moving on to the fixes.

Fixes, most likely first

Work down the list and stop when it's fixed.

1. 1

   It hasn't been calibrated

   How to tell. Open, close and stop work, but there's no position slider, or the web page says calibration is required. Switching to cover mode clears it, and a run that doesn't finish saves nothing.

   • Run the calibration

     In the cover's settings on the web page or in the app, open Calibration and start it. The blind runs fully open and fully closed on its own, so leave it alone until it finishes.

2. 2

   The movement time limit is too short

   How to tell. Calibration stops at the same point every time, before the end. Shelly's default limit is 60 seconds, and it warns that a low value can affect calibration.

   • Raise the movement time limits

     In the cover's settings, open Movement time limits and set the opening and closing times a little longer than your timed full run. The maximum is 300 seconds.

   • Calibrate again

     Run the calibration again once the limits are saved.

3. 3

   The motor's end limits aren't set

   How to tell. The blind reaches the end, but the motor keeps running until the time limit stops it. Shelly says the motor's limit switches must be set before the device is connected.

   • Ask your installer or an electrician

     Setting a motor's end limits is a job for your blind installer or a licensed electrician. Shelly recommends motors with electronic or mechanical limit switches.

4. 4

   The motor's direction is swapped

   How to tell. Pressing open closes the blind, in the app as well as on the wall. Calibration can also stop with a feedback error, because the motor turned the opposite way to the command.

   • Reverse the directions

     In the cover's settings, turn on Reverse directions. Up becomes down and the other way round, with no rewiring.

   • Calibrate again

     Run the calibration again after reversing.

5. 5

   The wall buttons are swapped

   How to tell. The app's open and close are right, but the wall buttons work the other way. That's the inputs, not the motor.

   • Swap the inputs

     In the cover's settings, turn on Swap inputs. The button that moved the blind up now moves it down.

   • Check the button mode

     Dual uses one button for each direction. Single uses one button that steps through open, stop, close, stop. Detached ignores the wall buttons altogether.

6. 6

   Obstacle detection is too sensitive

   How to tell. After a good calibration, the blind stops or reverses partway in normal use. Calibration sets the obstacle threshold to the motor's peak power plus 15%, so a stiff run can pass it.

   • Raise the threshold or the delay

     In the cover's settings, open Obstacle detection. Shelly says the power threshold should be a little above what the motor draws while closing, which the main controls show. A longer delay before detection starts ignores the start-up surge.

   • Check for a real obstruction first

     A blind catching on its track trips it for a reason. Clear the track before raising anything.

7. 7

   A protection or the safety switch is active

   How to tell. Calibration won't start, or stops at once. Shelly refuses to calibrate while an overpower, overvoltage, overcurrent or overheating error, or the safety switch, is active.

   • Clear it with one open or close

     Overpower and overcurrent clear on the next open or close. Overheating clears once it cools, and the safety switch once it's released. Then calibrate again.

   • Check the motor's size

     Shelly rates the 2PM Gen4 for motors up to 3 A. A bigger motor needs a different controller, which is a job for a licensed electrician.

8. 8

   Something interrupted the run

   How to tell. It stopped partway with no error you can explain. A wall button, the app, a schedule, Home Assistant or a firmware update restart all cancel a calibration.

   • Run it again with nothing else going

     Leave the buttons and the app alone, pause any schedules or automations for the blind, then start the calibration again.

   • If it still fails, update the firmware

     Shelly has fixed calibration for some motors in past releases. If it keeps failing on the latest firmware, ask an electrician to check the motor and its wiring.

On your device

Frequently asked questions