A013_F: Flame Lost After Established
Status
Flame loss is not a critical fault per say. However if repeated continuous failures occur, the system will go into a one-hour lockout.
Description
After a successful ignition trial where the flame was in fact sensed, the flame signal reduced or went away. This can happen after any successful proof of ignition.
Expected Operation
When the flame that was proven is lost, the blower will be energized if it weren't already and will run for the blower off period of 90 seconds. The inducer will continue to run and the ignition sequence will again take place. If the "T013_F: Flame Lost After Established " alert occurs 4 times in a single call for heat it will display A013_F: Flame Lost After Established or A114_F: One Hour Lockout: Flame Lost Failure.
Cause
The most common cause for flame sense to weaken is a dirty or corroded flame sense rod. A loss of gas supply from either a failed gas valve or from the source, such as running out of LP gas. An undersized or restricted gas line or inoperable external regulator can allow the furnace to fire fine and when the volume runs out it can cause the flame to reduce.
Solution
Clean flame sensor using steel wool or a crispy dollar bill. Do NOT use sandpaper or emery cloth to clean flame sensors. Check mounting of the flame sense rod, ensure proper furnace grounding, check for undesirable flame patterns.
Verify gas supply line is large enough, external regulator is working correctly, or no gas safety check valves have been activated.
