What to do if my Bosch SM070 compressor isn't working?
- CCrystal BakerAug 26, 2025
If the compressor on your Bosch Heat Pump isn't operating but the fan is running, it could be due to an open compressor overload. Check for supply voltage at the load side of the contactor. For 3-phase models, check the phase rotation and voltage at all 3 phases. Poor wiring connections can also cause this; look for signs of heat on the wiring insulation and ensure that all wiring connections are secure and properly torqued. A burned-out compressor is another possibility; check if the compressor hums when power is applied. If not, check the resistance of the compressor windings using the values shown in the compressor characteristics chart, ensuring the compressor is cool (70° F) when checking the windings.






