Aqua-Hot AHE-250-D03 error code BURNER FAILED TO IGNITE
Diesel burner attempted ignition but the photo-eye did not detect a sustained flame within the trial-for-ignition window. On the AHE-250-D03 the most common root cause is photo-eye lens contamination (60-70% of cases), NOT igniter or fuel hardware failure.
What to check, and in what order, is in the app. The flow Aqua-Hot — Diesel Burner Won't Ignite walks this code step by step with the pass/fail measurements, wiring schematics and procedures that go with it, and it works offline in the bay.
Start free trial 14 days free, no card neededDocumented in
- AquaHot 200-Series 250P/250D Service ManualAqua-Hot
Related codes
- OVERHEAT TRIPBoiler-coolant high-limit switch (215 deg F trip) opened, disabling…
- D1 LED OFFD1 is the Heating Status light (orange) on the relay control board …
- D4 LED NEVER ILLUMINATESOn the AHE-250 relay control board the indicator LEDs are D1 Heating…
- D5 LED OFF (OVERHEAT INDICATION)On the AHE-250 relay control board D5 = Burner Status (green) -- it…