Upon arrival homeowner stated that system was blowing cold air when running in heat mode. Upon diagnosis found system was low on refrigerant, recommend adding refrigerant to system and installing UV dye to perform a leak search at a later date. Homeowner approved repairs and also signed up on superhero club membership. Added 3 pounds of refrigerant to system and UV dye. System was putting out a 30° temperature rise and no other issues occurred. Informed homeowner office will call tomorrow morning to schedule a appointment to perform leak search.