Samsung Heat Pump Error Code E473

E473 indicates an indoor unit Electronic Expansion Valve open failure that has been confirmed on a second detection cycle. The EEV is not closing properly, which allows refrigerant to leak into an indoor unit that has been commanded to stop. This can lead to coil flooding, frost buildup, and compressor stress if left unaddressed. The first step is to verify that the EEV wiring harness is securely connected to the indoor unit PCB.

Continuing to run the system with an active E473 fault is not recommended. Refrigerant migrating into a stopped indoor unit can flood the coil, create pressure imbalances, and place added strain on the compressor. Prolonged operation in this condition can escalate a relatively straightforward EEV repair into more extensive and costly compressor or coil damage.

Because E473 is a second-detection fault, the system has already confirmed the problem through two diagnostic cycles, meaning a simple power reset is unlikely to resolve the underlying issue. The code may temporarily clear after a reset, but it will return if the EEV wiring, coil, or PCB problem has not been corrected. Resetting without repairing the cause can delay proper diagnosis and risk additional system damage.

A homeowner can visually inspect whether the EEV wiring connector is seated properly at the indoor PCB, which is the first recommended diagnostic step. However, any further diagnosis involving refrigerant pressures, component resistance measurements, or part replacement requires a certified HVAC technician. Working on the refrigerant circuit without proper certification is both a safety risk and a regulatory violation in most regions.

Repair costs vary depending on the root cause. If the fault is simply a loose wiring connection, the cost is limited to a service call fee, typically in the range of $75 to $150. Replacing an EEV coil or the full valve assembly can range from $150 to $400 or more in parts and labor. An indoor PCB replacement is generally the most expensive scenario, often running $300 to $600 or higher depending on the unit model.