Indicator Light blinking twice shows pressure switch is open will not allow blower or heat to work.

Test the pressure switch with a Ohm meter to see if it is making contact. Make sure any condensate hoses are free of moisture and/or debris. Check for a blockage in your venting system.

Turn off power. Pull vinyl hose off pressure switch and make sure it is clear of debris/water. Turn on power. Try again.

Lennox heater blinking all ones but four of them.. or maybe 1222? Blows cold airwhen heater is on.