Burner controls, ignition and flame safeguards
Kromschroder PFU 780 / PFU 760 Burner Control Unit fault codes
What all 15 Kromschroder PFU 780 / PFU 760 Burner Control Unit fault codes mean, in plain words, with a risk grade for each. These come from the manufacturer's own manual. The fix for each one is in WERCS Diagnose.
Get the fixes · plans from $49/moUpdated July 23, 2026
| Code | What it means | Risk |
|---|---|---|
| 2 | Blinking 2 The pilot burner failed to produce a flame signal during startup, causing a system lockout. | RED |
| 3 | Blinking 3 The pilot burner flame failed during the proving period, causing the system to lock out. | RED |
| 4 | Blinking 4 The pilot burner flame failed during normal operation, forcing the system to shut down immediately. | RED |
| 5 | Blinking 5 A flame signal is present on the main burner when none is expected, preventing startup. | RED |
| 6 | Blinking 6 The main burner failed to produce a flame signal during startup, causing a system lockout. | RED |
| 7 | Blinking 7 The main burner flame failed during the proving period, causing the system to lock out. | RED |
| 8 | Blinking 8 The main burner flame failed during normal operation, forcing the system to shut down immediately. | RED |
| 10 | Blinking 10 The system detected a faulty remote clearing signal, which prevents the burner control from operating normally. | YELLOW |
| 32 | Blinking 32 The supply voltage is too low, preventing the burner control unit from operating the equipment. | YELLOW |
| 33 | Blinking 33 Faulty parameter settings were detected in the control unit, causing the burner to lock out. | YELLOW |
| 35 | Blinking 35 A short circuit occurred on a valve output, forcing the burner control to shut down. | RED |
| 36 | Blinking 36 A short circuit occurred on the ignition or valve output, shutting down the burner system. | RED |
| 51 | Blinking 51 A safety interlock failure has occurred, forcing the burner system to shut down immediately. | RED |
| 52 | Blinking 52 The clearing input is being held active permanently, which prevents the burner control from operating normally. | GREEN |
| 53 | Blinking 53 The time between two startups is too short, preventing the burner from firing up again. | GREEN |
Every code comes from the manufacturer's own manual. Subscribers see which manual and page.