York TM9V080B12MP11 Error Code 7 Red Flashes: Ignition Failure - No Flame Detected

What Does Code 7 Red Flashes Mean?

On each ignition attempt the hot-surface ignitor heats up, the gas valve opens, and the board watches the flame sensor for a real flame. When no flame is confirmed after three trials, the furnace shuts the gas and enters a one-hour soft lockout before trying again. The code means the furnace tried in good order but never proved a flame.

The one cause a homeowner can safely address is simple: the furnace's gas valve on/off switch — or the manual gas shutoff feeding it — is in the OFF position, so no gas reaches the burners. That is why the first thing to check is whether the gas is actually turned on. Everything else the manual lists is technician-level: a failed or cracked hot-surface ignitor (the most common real cause), low or no gas pressure, a dirty or faulty flame sensor, loose wiring, or a faulty gas valve.

This code is about never establishing flame at all. It differs from the 8 Red Flashes code, where the furnace does light but then loses the flame five times during the cycle, and from the continuous amber warning, where flame is present but the sense current is weak.

What You'll Notice

• The furnace tries to start several times — you may hear repeated ignitor and gas-valve clicks — but never fires.
• Only cool air, or no air, is delivered, and the house does not warm up.
• After three failed tries the furnace goes silent for about an hour, then retries.
• The ignitor may or may not glow visibly, depending on which part has failed.

Common Causes

How This Is Diagnosed

The safe first check is whether gas is being supplied — the gas valve switch and the manual shutoff should be ON, and other gas appliances in the home should work. If gas is confirmed on and the code persists, a technician takes over in the manual's order: verifying the hot-surface ignitor actually glows and reaches temperature, measuring gas pressure, checking and cleaning or replacing the flame sensor, and inspecting the gas valve and wiring. Those steps involve gas pressure and the ignitor and valve, which are not homeowner tasks.

How to Fix It: Confirm the Gas Supply and Valve Switch Are On

What You'll Need

• Flashlight

Steps

1. Turn off power at the breaker or service switch AND shut off the gas supply before inspecting So you can safely look inside, flip the furnace breaker (or the wall service switch) to OFF and turn the gas shutoff valve to OFF (handle perpendicular to the pipe). If you smell gas at any point, stop, leave immediately, and call your gas company from outside.
2. Locate the gas valve switch and the manual shutoff Open the furnace access panel and find the gas valve; it has an ON/OFF selector. Also identify the manual gas shutoff valve on the pipe feeding the furnace. Note their positions so you can confirm they were meant to be ON.
3. Confirm gas is available to the home Check that at least one other gas appliance (such as a stove or water heater) works, which tells you the household gas supply itself is on. If no gas is reaching the home, the problem is upstream of the furnace and may involve the utility.
4. Restore gas to the ON position With inspection done, turn the manual gas shutoff back to ON (handle parallel to the pipe) and set the gas valve's ON/OFF switch to ON. Do not attempt to adjust or measure gas pressure — that is a technician task.
5. Restore power and let the furnace retry Switch the breaker or service switch back to ON. The furnace may need to clear its one-hour lockout, or you can cycle power to reset it, then set the thermostat to call for heat and watch the ignition sequence.

When to Call a Professional

Contact a licensed HVAC technician if:

• The gas is confirmed on but the furnace still fails to light after three attempts.
• The ignitor never glows during the ignition sequence, pointing to a failed hot-surface ignitor.
• You can hear gas trying to flow but it does not ignite, or the flame lights then immediately drops out.
• You smell gas near the furnace — leave first, call your gas company, then arrange service.

✓ Verified against manufacturer service manual — March 2026