HVACopediaSkytech · Gas fireplace
4 Beeps Every Second Sensor safety - flame sensed before ignition
What the control is telling you
The pilot flame sensor sees a flame when an ignition sequence starts, or the sensor is shorted to ground.
Applies to: Skytech AF-4000 MOD-1, AF-4000 MOD A and SMART MOD remote modules (used on many fireplace brands)
Likely causes
- Pilot flame actually present with the valve off (valve not closing)
- Flame sensor shorted to ground
- Failed pilot assembly or module
Test and repair steps
- Clear it press OFF, then ON to retry a normal ignition.
- Check whether a pilot flame is still there with the valve turned OFF; if yes, the valve must be replaced.
- Check the flame sensor and its lead for a short to ground.
- Replace the pilot assembly, then the module if the fault stays.
Models that show this code
3 models in AF-4000
Other codes on the same units
- 1 Beep Every 4 Seconds Communication safety - remote and receiver not talking
- 1 Beep Every Second Ignition safety - pilot did not light in 60 seconds
- 4 Beeps Every 2 Seconds Thermal safety - module overheated
Save it for the next call
Star this code in the HVACopedia app and keep the whole library on your phone for jobs with no signal.
Source: Skytech Audible Alerts & Error Codes for AF-4000 MOD-1 / MOD A / SMART MOD, p.2-3. 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.