High suction pressure and low discharge pressure in a heat pump system may indicate what issue?

High suction pressure combined with low discharge pressure in a heat pump system typically indicates a problem with the compressor's efficiency. When the compressor is not functioning properly, it may not be able to pressurize the refrigerant effectively. This inefficiency can lead to the refrigerant not being compressed to the appropriate discharge pressure, resulting in low discharge pressure, while the suction pressure remains high due to inadequate removal of heat from the evaporator.

The compressor's role is to convert low-pressure refrigerant vapor into high-pressure vapor. If the compressor is failing or inefficient, it cannot achieve the necessary discharge pressure even if the suction side is operating at high pressure. This scenario often points to issues such as internal wear, mechanical failure, or problems with the compressor's motor.

Understanding this relationship between suction and discharge pressures helps in diagnosing the heat pump’s performance and addressing issues related to compressor functionality.