Rheem Furnace Error Code 14

Full Diagnosis

Flame-proving circuit detects flame current at a point in the sequence when the gas valve is de-energized and no flame should be present — typically during standby, post-purge, or between trial-for-ignition attempts. On most Rheem/Ruud integrated furnace controls this is treated as a safety-critical fault distinct from ignition failures (11/12/13): those codes describe a flame that won't establish or won't hold, while 14 flags a flame signal appearing when the control never asked for one. The control locks out furnace operation (often escalating toward the code 10 soft lockout if it recurs) and will not attempt a normal restart until power is cycled and the fault clears.

All Recorded Causes

Gas valve stuck open or leaking through the seat, a shorted or miswired flame-rectification circuit reporting a false flame signal, a control board relay welded closed, or actual unintended flame at the burners with the valve commanded off. Because this can mean gas is flowing with no commanded ignition, shut off manual gas at the appliance, do not simply reset and run the furnace, and have a technician verify actual burner condition and valve operation before restoring power.

Verify Before Replacing Parts

1. Confirm the exact Rheem model family and furnaces context before acting on a generic code description.
2. Walk the entire heating sequence in order instead of jumping straight to the reported code, watching for gas valve stuck open or leaking through the seat, a shorted or miswired flame-rectificatio….
3. Verify each safety device and prove where the sequence stops under live operation, including whether because this can mean gas is flowing with no commanded ignition, shut off manual gas at th….
4. After the correction, run the system long enough to confirm the furnaces fault does not return under normal load.