my york diamond 80 system does not seem to be working. the system starts up, but refuses to blow air out into the vents. this happened after we had some ice/condensation on the refrigerant tube... i let the system to just dry off/warm up and turned on the heater as suggested by some. Now the blower does not come on and i noticed that the diagnostic LEDs blink 4 times on the circuit board Any advise before i have to fork the money to a repair tech?