Which of the following indicates a problem with the compressor in an HVAC system?

The identification of a compressor problem in an HVAC system can often be determined by observing specific pressure readings. In this case, lower than normal head pressure coupled with higher than normal suction pressure is indicative of an issue with the compressor.

Normally, a compressor should maintain a balanced pressure system, where the head pressure (the pressure on the discharge side) should be higher than the suction pressure (the pressure on the intake side). When the head pressure is lower than expected while the suction pressure is elevated, it suggests that the compressor is not effectively pumping the refrigerant through the system. This condition can be linked to various compressor issues, such as mechanical failure, wear, or insufficient refrigerant levels.

Viewing other choices in this context: normal operating head pressure typically indicates a well-functioning compressor. Inconsistent temperature control might suggest other issues in the HVAC system, such as problems with the thermostat or ductwork. Constant suction pressure alone does not provide enough insight into the compressor's health, as it could indicate steady operation or other non-compressor related issues.

Thus, the scenario where head pressure is lower and suction pressure is higher is key to diagnosing potential compressor malfunction, making it the correct answer.