Why won't the compressor start on my Daikin Altherma 3 R F Heat Pump for space or water heating?
- NNathan AtkinsSep 4, 2025
If the compressor in your Daikin Heat Pump isn't starting for space or domestic water heating, it could be because the unit is starting outside of its operation range, meaning the water temperature is too low. In this case, the unit uses the backup heater to reach the minimum water temperature first (15°C). Check that the power supply to the backup heater is correctly wired, and the backup heater thermal protector is not activated, and the backup heater contactors are not broken.