A114_F: One-Hour Lockout: Flame Lost Failure
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
Flame is lost after being established, 5 times in a single heat call.
Expected Operation
If the flame is lost after being established during iginitial trial, "T013_F Flame Lost after Established" alert is declared. The control transitions to post-purge and runs the blower through a blower off period of 90 seconds minimum. A new ignition attempt is made if the heat demand is still present.
If the IFC experiences five flame losses within a single call for heat, it will complete a post-purge and blower off delay before proceeding to a one-hour soft lockout at which time alarm “A114_F One-hour Lockout: Flame Lost Failure” is declared. Upon exiting the lockout, the alarm is cleared and normal operation resumes.
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.
