HVAC Troubleshooting 101

2. True or False: You should use sandpaper to clean a flame sensor rod to ensure that it is rough enough to catch the flame signal.

3. In the sequence of operation for an 80% gas furnace, what is the industry-standard warm-up time for a 120-volt igniter?

4. When a call for heat (W) first begins, the control board checks to ensure the pressure switch is in which position?

5. True or False: Since approximately 2019, many constant torque (ECMx) blower motors have transitioned from a 24V AC signal to a DC voltage signal (typically 8–18V DC).

6. Why does Jim advise against pulling the wires directly off a pressure switch to check for continuity?

7. What is a good reading for the flame rectification circuit?

8. True or False: Silicon carbide igniters are more durable than Silicon Nitride igniters and can be handled with bare hands without issue.

9. Jim mentions that "Smart Valves" often have sporadic failures because of their location near the burner. What is the common physical cause of this?

10. When an inducer motor is spinning but the pressure switch fails to close, what "hidden" physical failure should you look for?