The system does not blow cold air. The liquid line near the furnace does not gets real cold (mildly cold only)

Sounds like the furnace is tripping off on a limit safety, either temperature or air switch. Check filters and restrictions to air flow (furniture over return air grills, blocked filters) also, check the drainage line of the system. If the furnace can't drain water fast enough it will back up internally, and trip the system off on a pressure switch safety.

hope this helps.

If it is very cold out and you desire your house to be a certain temperature, you might have to raise your thermostat by 2 degrees to maintain it. Use Liquid Roof for

Check for stopped up filter and press reset on outside unit.will. located near Freon lines at bottom of unit

The AC unit outdoors must be running and rejecting heat by its air flowing through it the 2 copper lines are the refrigerant lines, the fatter one should be "beer can cold" if not its low on refrigerant or not running.

Hi,

Here is a tip that will help you try to figure out why your furnace is not working.

Basic Furnace or Heating System Troubleshooting

heatman101

Check your air filters and replace if necessary. Check the indoor and outdoor coils and clean if needed. If the line is still is freezing get the refrigerant charge checked.

An indoor blower running when it is not supposed to usually indicates an overheat condition. I would guess that it has been cycling on and off for some time and finally caused the high limit to stick and not auto reset. if you tap it sometimes they reset. the real problem is that it has been overheating from lack of airflow, over sized unit, not enough return air, too many closed registers, dirty filter, dirty squirrel cage blower and or air conditioner a-coil. If you get it started again sit and watch the unit run the flames should come on and stay on for the entire heating cycle, not going on and off.
I wish I could help you more but it is difficult without seeing the problem myself. Good luck! this should get you started!

you can do this your self it takes 134a however make sure low psi switch is working located on left side in accumalator neht to lg freon line suction they go bad you can jump it out with a small piece of wire on the plug side if gets real cold than switch bad if not low on gas make sure front coil is clean spray out with mild soap and water hope this helps

Make sure a back draft in the flue is not happening. Wind can blow it out until the flue heats up. The flame sensor may not be close enough to the burner flame. It may be weak and need to be replaced or if its an optical one it may be dirty and not see the flame very well. Its not wasting much gas but it puts extra wear and tear on the gas controls, is noisy, and, as you said, blows cold drafty air. A gas control system that has issues of any kind is not real safe. It needs to get fixed.

when an AC gets real hot and there is air in the system you get what is called High Head Pressure and the high pressure switch will not let the clutch engage. Need to have the system evacuated and recharged.