HVACopediaMajestic · Gas fireplace
3 RED No sensor signal
What the control is telling you
Three red flashes: the control does not see a flame signal from the pilot sensor.
Applies to: 300DVBLN/PSC7, 400DVBLN/PSC7, 500DVBLN/PSC7 (Signature Command)
Likely causes
- Pilot sensor not sitting in the pilot flame (flame too small)
- Pilot connections loose
Test and repair steps
- Check the pilot connections at the control board
- Adjust the sensor position in the flame or replace the pilot assembly
Other codes on the same units
- 1 RED / 2 sec (until reset) Pressure switch failure (power vent only)
- 1 RED-GREEN / 2 sec Pilot lockout - flame loss
- 2 BEEPS Double beep (confirmation)
- 2 RED Spark fail
- 2 RED / 10 sec No or low thermopile power
- GREEN FLASH 1/sec Learning mode
- GREEN SOLID AC power on
- NO BEEP No beep after master switch ON
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Source: Majestic DVBL7 Series Installation and Operating Instructions, p. 41, p. 48. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.