Commercial heat pumps are highly efficient, but their complexity increases with the Reversing Valve and Defrost Logic. Using AC/C TECH HVAC/R diagnostic protocols, we isolate the failure point between mechanical and electrical components.
Reversing Valve Solenoids and Defrost Cycles
If a heat pump is stuck in cooling mode during a Seattle winter, we first test the reversing valve solenoid coil for 24V from the thermostat. If voltage is present but the valve doesn’t shift, we use a magnet to test for a stuck internal slide. Furthermore, we test the defrost board logic. If the outdoor coil is iced over, the defrost sensor may be out of calibration, preventing the system from temporarily switching to “Cooling Mode” to melt the ice.
Why is my commercial heat pump blowing cold air in heat mode?
The most common cause is a failed reversing valve solenoid or a defrost board malfunction. If the system stays in defrost mode too long without the auxiliary heat strip engaging, the facility will experience a rapid temperature drop.
Expert Heat Pump Service
Keep your facility efficient year-round with our specialized heat pump diagnostics.
- Call: (425) 535-8990
- Service: Same-Day Commercial Heat Pump Repair