Upon arrival scheduled No Heat call, I was shown to an air handling unit located vertically in a hallway closet. The homeowner had stated ever since the systems thermostat was changed out he had no heat in capability. Upon inspection, I found the system is equipped with a one heat one cool thermostat which is incorrect for this system. This system needs a to heat one cool thermostat to be able to use the heat pump as well as the electrical heater kit inside the air handling unit. I added an estimate to replace the thermostat to the invoice to be able to view pricing. homeowner won’t be moving forward with work at this time. I did also noticed that the heating sequencer had failed and was not sending any high voltage power to the heater kit itself. Replaced the heating sequencer with a high-voltage contactor in this place to be able to send high voltage to the heater kit when the system is calling for heating. Cycle functions and heating is working properly at this time. I did not