Furnace will not start at all; no inducer, no blower, no LED lights on the control board.

Safety first: You are working with line voltage. If you are not comfortable, contact a professional. Always turn off the breaker before opening junction boxes.

• Check breaker and switch: Verify the furnace breaker in the electrical panel is ON. Locate the furnace service switch (often on or near the unit) and ensure it is ON.
• Inspect blower door switch: Ensure the blower compartment door is properly installed and depressing the door safety switch. The furnace will not power up if this switch is open.
• Look for control board LED: Remove the blower door and check for any LED activity. If dark, test for 120 VAC at the furnace line terminals and 24 VAC at the transformer secondary.
• Check transformer: If 120 VAC is present but no 24 VAC, the transformer may be open. Replace with a Payne-compatible 40 VA (or as specified) transformer.
• Inspect wiring connections: Tighten any loose wire nuts or terminal screws in the furnace junction box and on the control board.