Why it matters to you
If a Charleston heat pump cools fine in summer but blows cool air when you call for heat, or the reverse, a stuck reversing valve or its control is one of the likely causes.
Practical guidance
A brief whoosh when the system changes modes or starts a defrost is normal. If the system will not switch between heating and cooling, call a licensed technician; diagnosing and replacing the valve involves the sealed refrigerant circuit.
