[equinta]

i'm having a problem with my furnace, the unit comes on and blows cold air. it has done this 2 nights this week. on wednesday AM i just went downstairs opened the top cover, turned off the emergency switch and turned it on and it began to work. i still had a technician come over and take a look and he said it all checked out OK, he looked at the thermostat and found some loose wires and blamed it on that. (I was skeptical.) sure enough Thursday night same thing happened. before resetting it via the emergency switch i opened up top and bottom panels so i could watch the board to look for a error code. i pressed the switch for the lower panel, the unit little fan came on and the ignitor started getting red, the flames came on the big fan came on. The flames turned off and the ignitor came back on and the flames turned on. the flames went out again and the ignitor again came back on. the flames came on again, then the flames went out again and the unit turned itself off. the red light on the control board flashed 7 times in 3 seconds and it kept flashing this sequence until turned it off at the emergency switch. does any know what the 7 flashes mean on this furnace?

 

[mdshunk]

The flash codes should be on a chart inside the furnace door in the section that houses the control board. From where you describe your furnace stopped in the sequence of operations, I'd say that there's a 90% chance you need to clean the flame sensor. It's a wire rod type sensor with one wire connected. It's held in place with one screw. There's a weird oxide that builds up on the flame sensor (more readily in damp basements), that needs cleaned off. Remove the flame sensor and scrub the metal portion with steel wool or fine emory cloth and reinstall. I'm betting that will fix you up.

 

[rakes9720]

Clean the flame sensor, and then make sure that the control board (with the error code light on it) is grounded. This ground is important to sense the flame.

 

[NickTech]

make sure that flame rod is engulfed in the flame, and that the burner manifold is ignited completely.

 

[equinta]

The flash codes should be on a chart inside the furnace door in the section that houses the control board. From where you describe your furnace stopped in the sequence of operations, I'd say that there's a 90% chance you need to clean the flame sensor. It's a wire rod type sensor with one wire connected. It's held in place with one screw. There's a weird oxide that builds up on the flame sensor (more readily in damp basements), that needs cleaned off. Remove the flame sensor and scrub the metal portion with steel wool or fine emory cloth and reinstall. I'm betting that will fix you up.

thanks for the advice, the problem reoccurred just a few minutes ago, i cleaned the sensor and unit started right up. i will keep you posted if it reoccurs. thanks for the words of wisdom. no chart on inside of furnace...maybe i didn't look hard enough... :cheesygri Thanks again!!!! :Thumbs:

 

[equinta]

Clean the flame sensor, and then make sure that the control board (with the error code light on it) is grounded. This ground is important to sense the flame.

it just happened again, i cleaned the sensor and it started right up. it's kind of late right now so i'll check the ground on the control board tomorrow AM thanks for the advice :Thumbs: