When an oil burner motor only starts when the shaft is first turned by hand, what is wrong?

• A. burner nozzle clogged
• B. start switch and/or capacitor is not working
• C. relay stuck
• D. pilot light out

Answer: (B)

Oil burner motors use a starting circuit to develop the initial torque needed to start. A single‑phase motor relies on a starting winding with a capacitor and a start switch to energize at start-up. If you can get it running only by turning the shaft by hand, the starting circuit isn’t energizing properly—typically a faulty start switch or a bad capacitor. Once you give it a push, the rotor has momentum and the run winding can keep it going. The other issues don’t fit the symptom: a clogged nozzle or a pilot light problem affect combustion, not the motor’s ability to start on its own; a relay sticking could prevent starting, but manual rotation points to the starting device being the culprit.