My furnace is blinking 3 times and won't turn on. I have a Trane XR80 and no manual or trouble shooting codes. Could somebody please tell me what it means when it blinks red 3 times and won't turn on? Thanks... very cold:confused:!!

Look on the inside of the blower door for the trouble codes.

According to the manual it's the following:

Draft Pressure Error - Possible Problems:
Venting Problem
Pressure Switch Problem
Inducer Problem

Same issue: fan comes on for about a minute then shuts off, flame never comes on, and indicator blinks three time repeatedly. Pressure switch good... closed with pressure, open with no pressure. Rest of circuit (yellow wire loop) closed circuit (24VAC loop good). While incidentally moving orange wire from pressure switch to control board, noticed a change in the indicator and triggering of relays on the control board. With power off, unplugged cable assembly from control board and reseated it. Working like a charm now! (hvac1000 & JLeggs73, your replies narrowed down the troubleshooting... thanks!)

I just had that problem had to buy new circuit board easy to install. $189.00 for part.

I did not replace filters when [I] should have. I believe the gas is not igniting because the limiting switch is turned off. After replacing the filters, is there a reset button for the switch to allow the gas to ignite?

My Trane must have a similar problem except the problem comes and goes. For instance the other morning it was turning on via the thermostat, the blower fan starts, burners ignite and then after 45 seconds or so it shuts down. This repeats. I turned off the power to the whole furnace (thinking a "rebout" might help) and then with the thermostat in the off mode and the power on again I activated the heat mode and it started and ran just fine.

So this AM I get up and the thermostat is set on 64 and the temp is 64 so I bump it up to 65 and the furnace starts and runs just perfectly. Then 10 minutes later the vent fan starts but the furnace doesn't. This repeats for several cycles until I turn down the thermostat to 63. The error code is three flashes. Pressure switch. How does it work sometimes and not others?

I had the same issues (3 blinks, and the pressure switch circuit was fine). Unplugged unit, disconnedcted and reconnected sensor wires at controller board, plugged unit back in, reset thermostat, and presto! Works like a champ. Thanks to all for the previous posts.

I bought a new switch for $25.00. Took all of about 5 minutes to install. Furnace has worked since except for one time when it acted like it did prior.

OK after several weeks of proper function the same old thing started again. Cycling on and off with no ignition. Three quick flashes indicating the pressure switch as the culpret. Well since it is new I looked elsewhere and found the problem. The tubing connected to the pressure switch comes form the Combustion chamber and the "pressure" is then sent out the other side of the switch to the gas valve and to somewhere else. THE CHEAP PLASTIC ELBOW THAT "FITS" INTO THE GAS VALVE WAS VERY LOOSE! Teflon tape tightened that connection as well as the others and with that I think I'm moving on!

My furnace keeps going out after it ignites can this be caused by a dirty filter

What does Continuous Replace IFC the LED stays on all the time- no flame, no glow nothing
I have an American Standard Freedom 80 Furnace. My thermastat will not even come on. I replaced the circuit board because it had major melt issues. Any ideas what I might have done wrong. I connected each wire and bracket one at time when switching from the old to new.

I read a post that advised disconnecting the connector from the controller board, and then plugging it back in. I did that, and the problem went away. Kind of like rebooting your PC. Could it be "windows furnace edition?" :-)