Danfoss TP5000si Problems

The Danfoss TP5000si thermostat has been a reliable device for many users. However, like any electronic device, it can sometimes encounter issues. One such problem observed with the thermostat is a malfunctioning display. This article delves into the details of this issue, its potential causes, and proposed solutions.

The Issue

Some users have reported that the thermostat’s display, which usually shows the current time, instead shows two flashing dots. Accompanying this display malfunction, the temperature reading was also observed to drop to 5°C. Even when adjusting the temperature to the typical room temperature setting (around 20°C), the device seemed to activate the heating system correctly. However, the thermostat appeared to cycle the heating on and off more frequently than usual.

Initial Solutions Attempted

1. Manual Resets: Many users initially tried to implement the reset solutions detailed in the device’s manual, but these were not effective.
2. Battery Replacement: Changing the batteries was another troubleshooting step tried, but the issue persisted even after replacement.

Potential Causes and Solutions

1. Battery Issues:
   • Cause: Using rechargeable batteries instead of alkaline batteries can cause issues. Rechargeable batteries generally have a lower voltage compared to alkaline batteries.
   • Solution: Always use good quality alkaline batteries. Even if the low battery symbol does not appear, replacing the batteries with fresh alkaline ones can be a helpful step.
2. Wireless Pairing: Some thought the flashing could indicate a lost pairing with a receiver, which would be a concern for wireless units.
   • Solution: While this was not the case here (as it was a wired unit), for wireless models, re-pairing with the receiver might be necessary.
3. Wired Unit Confusion: The presence of batteries in a wired unit can be confusing. However, several hard-wired thermostats utilize batteries, particularly those that do not need a neutral wire. The batteries can serve as a backup, ensuring the thermostat remains functional even during power outages.
4. Service Interval Control:
   • Cause: The SI (Service Interval) control feature is designed to stop the thermostat from working if the system isn’t maintained regularly. This feature is often present in models installed in rental properties.
   • Solution: Ensuring regular maintenance of the heating system and getting the boiler serviced can reset the SI control, restoring the thermostat’s functionality.
5. Retrospective Installation: Sometimes, the thermostat could be a retrofit, replacing a standard thermostat. In such cases, the original programming might be bypassed or set to ON, letting the TP5000si take over time and temperature control functions.
6. Exiting Frost Setting: The issue might be related to the thermostat being in a ‘frost setting’.
   • Solution: Pressing the up and down arrow buttons together can help. If that doesn’t work, refer to the manual on how to remove the programmer from the frost setting.

Conclusion

If your Danfoss TP5000si thermostat displays anomalies, consider the above points. While some solutions can be tried at home, it’s always a good idea to consult with professionals or reach out to the manufacturer’s support for more detailed troubleshooting. Regular maintenance and understanding the features of your thermostat can also prevent potential issues in the future.