TRVZB Smart Valve Retention Ring – Anti Drop Fix

Internal Safety Ring for Sonoff TRVZB (Anti-Pop Valve Retention)
 

This small internal ring is designed to solve a critical issue I experienced with the Sonoff TRVZB smart thermostatic valve:
under certain conditions, the plastic claws can be pushed together too much by the radiator pin, allowing the whole valve body to slip out of the metal mounting ring, fall to the floor and leave the radiator fully open (always heating).

By adding this 3D printed internal ring inside the TRVZB, the plastic claws can no longer over-tighten, so the valve body stays securely locked in place.

🛠 What this part does

• Prevents the TRVZB body from popping out of the threaded metal ring
• Keeps the valve securely attached to the radiator, even when the pin pushes strongly
• Avoids the “valve fell off and radiator is stuck fully open” scenario
• Drop-in, fully internal part: invisible from the outside once installed

🧩 Installation steps

1. Remove the TRVZB from the radiator
   Unscrew the metal retaining ring of the valve and gently remove the TRVZB from the radiator.
2. Remove one battery
   Take out one battery to make sure the valve does not move during installation.
3. Insert the 3D printed internal ring
   Insert the printed internal ring into the inner seat of the TRVZB, where the radiator pin normally presses (the opening/closing pin area).
4. Reinstall the valve on the radiator
   Place the TRVZB back onto the radiator and screw the metal ring again until the valve is firmly fixed in place.
5. Reinsert the battery and recalibrate
   Put the battery back in and press the central button to start the calibration process so the valve can learn the new mechanical position.

With the internal ring in place, the plastic claws of the TRVZB can no longer compress too much, so the valve body cannot slip out of the metal ring and fall off.

⚠️ Disclaimer

• This is an unofficial, user-made fix for the Sonoff TRVZB.
• Always check that the valve is firmly attached and that calibration completes successfully after installation.
• Use at your own risk; monitor the first days of operation to be sure everything works as expected.