Heat pump blowing cold in heat mode could mean defrost trouble, low refrigerant, or a stuck reversing valve

https://jasperussr693.timeforchangecounselling.com/strange-hvac-noises-and-what-they-usually-mean

Heat pump blowing cold in heat mode could mean defrost trouble, low refrigerant, or a stuck reversing valve. Don’t wait—quick diagnostics in Alpharetta can spare you higher bills and longer run times.