Error E9. What does it mean and what should I do?

Error E9: restricted valve closing ability. Danfoss Eco™ is installed on the valve incorrectly.
Pease check the installation following the next steps:

1. Be advised that Danfoss Eco™ should have enough free space in place of installation for precise room temperature measurement. It means Danfoss Eco™ shouldn’t be covered by curtains, decorative radiator coverage, furniture, etc. Also, distance between installed thermostat and another heat source (radiator, pipe, riser, etc.) should be enough long to prevent negative influence on the temperature regulation performance.  

2. Check if valve’s spindle moves (up/down) without any resistance and does not have any leakage;

3. Check if adapter was matched according to the valve type (installation video:;

4. Make sure that adapter and Danfoss Eco™ is tighten enough. Screw Danfoss Eco™ onto the mounted adapter until a click sound appears;

5. Pull one battery out and put it in Danfoss Eco™ again. This action will launch valve exercise procedure (from fully opened to fully closed position);

6. If after applying four steps above the issue remains the same, we highly recommend you to get technical support by the link: or contact our Customer Service Center: 24/7 - International number, Tel.: +331 83 82 37 90.