Showed up to find system operational, spoke with client about what was going on. Client stated that when it’s super cold outside, the heat pump outside will blow out cool air, inspected air filter and found an air filter to be extremely dirty. Heat pumps traditionally do not keep up well in extremely cold weather, which is why they have emergency heat, recommended client to keep emergency heat on while it was super cold outside, and when it begins to warm back up to turn the system back onto regular heat. Tried to call multiple different people to get someone out there to replace the air filter, no one answered any of the phone calls, system needs an air filter put in it and I did not carry one on my truck for that size.
