York TM9V080B12MP11 Error Code Continuous Amber Flash: Low Flame Sense Current

What Does Code Continuous Amber Flash Mean?

Unlike the slow amber flash that marks a normal heat call, a continuous amber flash is a warning: the control board is measuring flame-sense current below its 1.5-microamp minimum. The flame sensor is a thin rod placed in the burner flame that conducts a tiny current through the flame back to the board; that current is how the board proves a flame is actually present. When the reading sags below threshold, the furnace keeps heating for now, but it is operating on a marginal signal.

The most common reason is a flame sensor coated with oxidation and combustion residue, which insulates the rod and starves the current. Insufficient gas flow is the other listed cause — if the flame does not fully wrap the rod, the signal weakens even on a clean sensor. On this York model the manufacturer's procedure includes verifying that the current measured at the flame-current test pad is greater than 1.5 microamps, which is a metered check rather than a visual one.

This warning is closely related to the 8 Red Flashes code, which is set when the flame is actually lost five times during a cycle and the furnace locks out for an hour. Think of continuous amber as the early warning and 8 Red Flashes as what can follow if the weak signal is ignored.

What You'll Notice

• The board LED flashes amber continuously, with no pauses, rather than the slow two-second amber of a normal heat call.
• The furnace still lights and heats, but it may feel like it is running on borrowed time.
• Occasional unexpected shutdowns or a later escalation to an 8 Red Flashes one-hour lockout as the signal degrades further.
• The warning often appears more readily on a furnace that has run a full season without flame-sensor service.

Common Causes

How This Is Diagnosed

Because this model marks the code as needing a metered check, diagnosis is a technician's task. The technician isolates the cause by first cleaning the flame sensor rod and re-measuring current at the flame-current test pad, confirming it now reads above 1.5 microamps. If a clean sensor still reads low, attention shifts to gas flow — verifying manifold pressure and that the burner flame fully envelops the rod — and to the sensor wiring and ground, since a poor ground also reduces the microamp reading.

When to Call a Professional

This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:

• The continuous amber warning persists, or the furnace has begun shutting down during cycles.
• The LED has escalated to an 8 Red Flashes one-hour lockout (flame lost five times).
• The burner flame looks yellow or lazy rather than crisp and blue, which can indicate a gas-flow or combustion issue.
• The warning returns within a short time after a previous flame-sensor service.

✓ Verified against manufacturer service manual — March 2026