Our furnace is only blowing cold air and the blower will not shut off with the thermostat. The indicator light flashes 2 times-and the code thing says it means system lockout -check line clarity.:confused: The ignitors try to light but go out right away. Now it is flashing constantly meaning internal control failure replace?? Help it is very cold Model Number-HA02230D175B160567 ---American Standard Freedom 80

A couple of things that will case this. Dirty air filter. Low gas pressure. No flame sensed. Service the air filter, clean both the flame sensor found on the far left of the burner box with a stiff brush and the flame tray. You want the flame to spread to all burner tubes and hit the flame sensor within a few seconds. More than 5 seconds and the flame goes out on safety. There is a flame tray that helps send the flame from one burner to the next. Any debris in it and it will either not allow the flame to pass or slow it down. If that does not help , get a technician in to check your gas pressure.

We have an Ameristar HFurnace that is nearly five years old, but a red scenso light flashes. What does that mean.