Why is my furnace not comining on

SOURCE: Coleman Furnace

Based on the info you have given here, I am going to make some assumptions. In "cleaning out all the components" you cleaned the air filter or changed it, cleaned the duct-work, and the intake combustion chamber? When the "furnace stays lite" the pilot and the main burner stays on? Lastly, when it "continues to blow cold air" is this when the main burner is on after long periods of time? If the answers are all yes, then maybe some of the ducts have come off, or the burners aren't working correctly.

SOURCE: Coleman presidential II furnace blower on and off

Sounds like the flame sensor. But it could be the thermostat. Is the furnace standing pilot or electronic spark or hot surface ignition. I would start by checking thermostat. Turn power off to furnace take thermostat off wall and take wires marked r & w and connect them together. Turn power back on if furnace works then change out thermostat.Most eclectronic ignition Furnaces have a flam sensor, You could take flame sensor out and clean it up with steel wool or wire brush. If you need anymore help just reply back .

SOURCE: Rheem gas furnace blower unit not working properly

look at circuit board and follow wires that come from fan motor, if this is a standard motor black is high and it will be going to a prong that says cool, red is low and it will go to heat, you will have a yellow and a blue that are "parked" remove red park it were the blue is and put blue on heat, if this is a variable speed motor you will have to set dip switches via your equipment manual

SOURCE: Ruud Silhouette II Gas Furnace, purges, lights

Flame sensor needs to be cleaned. turn off the furnace power switch or breaker. pull the flame sensor located in the burner runner section of the furnace. It will be easy to locate because it has 1 wire running to it. pull the screw being very careful not to harm anything else. get the sensor out. inspect it for cleanliness. clean the sensor with light grade sand paper gently. re-install the sensor plug the wire back on. restart your furnace and this should fix the problem.
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SOURCE: Nordyne furnace. The furnace comes on, flame

Hello. The first thing you can do is check the flame sensor, this is a small metal rod on the opposite side of the ignitor, Turn off power to the unit remove flame sensor and clean it with some steel wool. Also check the flame sensor to make sure there are no cracks in the base of it, if so then replace the flame sensor. If you have checked the flame sensor and the problem still continues you might have a problem with the unit not being grounded properly, you should have a ground wire coming from the main electrical panel to the furnace. If the ground wire is there and problem continues the control board should be replaced. I hope this helps.