What might happen if a crankcase heater fails?

When a crankcase heater fails, one of the primary consequences is that the oil within the compressor can thicken. This thickening occurs because the crankcase heater is designed to keep the oil warm, ensuring it remains in a fluid state. Warm oil is crucial for reducing viscosity, ensuring proper lubrication during startup conditions.

If the oil thickens due to the failure of the crankcase heater, it can lead to challenges when the compressor tries to start up. Thick oil can make it difficult for the compressor to turn over, potentially causing increased wear and tear on the motor and mechanical components. This can lead to eventual compressor breakdown or failures due to insufficient lubrication, which is critical for proper operation.

The other options involve scenarios that do not directly relate to the failure of a crankcase heater. Continuously running compressors or issues related to refrigerant freezing are more associated with other problems within the system, while over-pressurization typically involves issues with pressure regulation or control, rather than the oil's condition impacted by the crankcase heater. Thus, the thickening of oil leading to startup issues is the most immediate and pertinent consequence of a crankcase heater failure.