Bosch Split CS SM048 User Manual (English)

Questions and Answers:

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mchristianAug 9, 2025
Why is my Bosch Split CS SM048 not cooling or heating enough?
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  Beth JohnsonAug 9, 2025
  Insufficient cooling or heating in your Bosch Heat Pump can stem from several causes. The unit might be undersized, requiring recalculation of heating/cooling loads, possibly with added insulation. Leaks in ductwork or ambient air entering through doors/windows could cause loss of conditioned air. Inadequate airflow, often due to a dirty filter, can also be a factor. A low refrigerant charge leads to inefficient operation. Other potential issues include a defective compressor or reversing valve, restrictions or defects in the TXV, or contamination of the refrigerant system with moisture or non-condensables. Compare the unit's operating pressures to the pressure/temperature chart to diagnose the issue.
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Karen MitchellAug 15, 2025
What to do if my Bosch Split CS SM048 Heat Pump is not running at all?
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  Alexandria ReyesAug 15, 2025
  If your Bosch Heat Pump isn't running, start by checking the power supply. Ensure the disconnect is closed and power is applied. Inspect for blown fuses or tripped breakers, replacing or resetting them as necessary, ensuring correct fuse size. Verify the voltage supply meets the unit's data plate specifications; if it's low, contact your local power company. Also, examine the thermostat. Set the fan to 'ON' to see if the fan runs. Test 'COOL' and 'HEAT' modes with extreme temperature settings to check for proper operation. If issues persist, confirm 24 volts at the low-voltage terminal strip between 'R' and 'C,' 'Y' and 'C,' and 'O' and 'C,' and between 'G' and 'C' in the air handler. Replace the thermostat if it's defective.
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Scott ParksAug 20, 2025
Why does my Bosch Split CS SM048 Heat Pump turn off due to high pressure?
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  rogersrobertAug 20, 2025
  Your Bosch Heat Pump might be shutting down due to high pressure for a few reasons. In 'COOLING' mode, check for insufficient water flow, excessively warm entering water temperature, or a scaled/plugged condenser. In 'HEATING' mode, ensure adequate fluid flow on the load side, and verify the blower is operational, the filter isn't clogged, and ductwork isn't restricted. An overcharged refrigerant level can also cause this issue; in that case, reclaim refrigerant, evacuate, and recharge to the factory-recommended level. Finally, inspect the high-pressure switch for defects or improper calibration.