Burner controls, ignition and flame safeguards
Riello RDB 2.2 Burner Control (MO 535 - MPF) fault codes
What all 9 Riello RDB 2.2 Burner Control (MO 535 - MPF) 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 |
|---|---|---|
| Red steady on | Reset button: steady red The burner control locks out because no flame was established at the end of the safety time. | RED |
| Orange steady on | Reset button: steady orange The burner control locks out due to a mains supply frequency error, stopping the heating system. | GREEN |
| Red blinking (0.5s/0.5s) | Reset button: red blinking The burner control locks out because a false flame or extraneous light signal was detected. | RED |
| Red fast blinking (0.2s/0.2s) | Reset button: red fast blinking The burner control locks out after reaching the maximum number of recycles due to repeated flame failures. | RED |
| Green + red blinking (0.5s/0.5s) | Reset button: green and red blinking The burner control locks out because it detects extraneous light or a false flame signal. | RED |
| Orange + green blinking (0.5s/0.5s) | Reset button: orange and green blinking The burner control locks out due to an internal memory error, preventing the burner from starting. | RED |
| Orange + green fast blinking (0.2s/0.2s) | Reset button: orange and green fast blinking The burner control locks out due to an internal voltage monitor error, preventing burner operation. | GREEN |
| Red + green inverted flashing (2.5s/0.5s) | Reset button: red and green inverted flashing The burner control locks out due to an internal control circuit fault driving the oil valve. | RED |
| Red + orange inverted flashing (2.5s/0.5s) | Reset button: red and orange inverted flashing The burner control locks out due to a fan motor error, stopping the combustion process. | RED |
Every code comes from the manufacturer's own manual. Subscribers see which manual and page.