The sequence matters more than a parts list

A furnace goes through checks before and during heating. For example, Daikin's DM96TN/DC96TN instructions (July 2023) place protective checks and inducer operation before igniter operation. The inducer is the small fan that moves combustion exhaust. Your model's sequence governs its testing. Daikin heating sequence, pages 39–40.

That is why a new igniter cannot answer every no-start problem. The technician needs to establish whether the control is calling for ignition, whether the preceding conditions are satisfied, and whether the installed part is correct. Those are professional tests, not a request for you to touch wiring or jumper a safety control.

Ask: “Where did the sequence stop, what test confirmed the cause, and why will this repair address it?” That question is more useful than asking which part to buy next.

Prepare a useful handoff

Keep receipts and packaging if available. Write down whether the furnace was silent, ran a small fan, glowed, lit then stopped, or moved room air without heat. Record an existing display code without clearing it or removing covers.

Do not repeat the failure for a video. Do not restore or change internal wiring yourself just to make the unit look original. Tell the service company about the present configuration before it is used.

We recommend asking the technician to verify compatibility and installation of the changed parts as part of the visit. Even if those parts were not the original cause, the current setup still needs checking.

Judge the recommendation by its evidence

A correct diagnosis may lead to one repair, correction of an earlier change, or further assessment. It should not leap from “two parts did not help” to replacement without explaining the finding and alternatives.

Request the complete repair price, what it would resolve, and what would remain uncertain. Ask how a normal cycle and the relevant protective controls will be checked afterward.

If the home is losing needed winter heat, confirm the appointment and an update time. Arrange another warm place if the household cannot remain adequately warm while waiting. Do not use repeated resets or a bypass as temporary heating.

Your next action is to book a diagnostic visit and send the parts history with the original symptom. That gives the technician the evidence needed to move beyond guessing.