Burner controls, ignition and flame safeguards
Riello RS/E BLU Burner Control (REC 27.100A2 with RDI21 display) fault codes
What all 24 Riello RS/E BLU Burner Control (REC 27.100A2 with RDI21 display) 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 | No flame at the end of the first safety time (TSA1) The burner control box locks out because no flame was detected at the end of the first safety time. | RED |
| 4 | No flame at the end of the safety time (2) The burner control box locks out because no flame was detected at the end of the second safety time. | RED |
| 7 | Extraneous light The burner control box locks out because it detects extraneous light inside the combustion chamber. | RED |
| 12 | Loss of flame during operation The burner control box locks out because the flame was lost during normal operation. | RED |
| 20 | Air pressure error The burner control box detected an air pressure error, which locks out the burner. | RED |
| c: 2 | c: 2 (alternating with d: 1 / d: 2 / d: 4) The burner control box locks out because no flame was detected at the end of the ignition safety time. | RED |
| c: 3 | c: 3 (alternating with d: 0/1/4/20/68/84) The system detected an air pressure error at startup, which locks out the burner. | RED |
| c: 4 | c: 4 (alternating with d: 0/1/2 and combinations) The burner control box locks out because it detects extraneous light during startup or shutdown. | RED |
| c: 7 | c: 7 (alternating with d: 0/3) The burner locks out because the system detected a loss of flame during operation or testing. | RED |
| c: 12 | c: 12 (alternating with d: 0/1/2/3/4/5) The burner locks out because the system detected a leaking gas valve or a configuration problem during the leak test. | RED |
| c: 14 | c: 14 (alternating with d: 0/1/64) The burner locks out at startup because the proof of closure switch is in the wrong position. | RED |
| c: 20 | c: 20 (alternating with d: 0/1) The system detected a lack of minimum gas or oil pressure, which locks out the burner at startup. | RED |
| c: 21 | c: 21 (alternating with d: 0/1/64) The maximum gas or oil pressure was exceeded, which locks out the burner at startup. | RED |
| c: 22 | c: 22 / OFF S (alternating with d: 0 and combinations) The burner locks out at startup because the safety circuit or burner flange is open. | RED |
| c: 60 | c: 60 (d: 0) An internal error occurred because there is no valid load checking device, which locks out the burner. | RED |
| c: 70 | c: 70 (with d: 23 / d: 26) A fuel and air checking error occurred during modulation position calculation, which locks out the burner. | RED |
| c: 71 | c: 71 (with d: 0/1/2/3) The burner stops because a special position like standby, purging, or ignition is not defined for the servomotors. | RED |
| c: 85 | c: 85 (with d: 0 / d: 1) The burner stops because the fuel or air servomotor failed to reach its required reference position. | RED |
| c: 93 | c: 93 (with d: 3) The burner locks out because there is a flame signal acquisition error caused by a short circuit in the sensor. | RED |
| c: 95 | c: 95 (with d: 3/4/5/6) An active contact caused a relay supervision error with the external power supply, which stops the burner control from operating the valves or ignition transformer. | RED |
| c: 96 | c: 96 (with d: 3/4/5/6) A relay supervision error indicates that the relay contacts have welded together, which locks out the burner. | RED |
| No Comm | No Comm The burner control box lost communication with the display, preventing the operator from monitoring the system. | YELLOW |
| c: 50 to 58 | c: 50 to c: 58 The burner locks out due to an internal error in the control box. | RED |
| c: 86 / c: 87 | c: 86 (fuel servomotor) / c: 87 (air servomotor) The burner stops because a servomotor failed to reach its target position within tolerance or has an open circuit. | RED |
Every code comes from the manufacturer's own manual. Subscribers see which manual and page.