Came out to call for a system not heating properly. Customer stated that the inspector told him the heater worked before he purchased the house, but it hasn’t worked since he tried to turn it on. I checked system over and found that the unit has a relay that’s not relaying the signal to kick the air handler on properly. I did not have the same relay and will need to pick one up. Will schedule to come back and fix the issue. No one lives in the home at the moment. They are remodeling. Came out and replaced the relay in the air handler. After installation of the new part and double checking the wiring, I cycled system on from the thermostat and heating elements and blower came on with no other issues present at this time. Discussed with customer about having maintenance done on the system starting in the spring. Made him aware of the contactors that control the heating elements are starting to become pitted. He wants to hold off on any other repairs at this time, and see how the unit do