Expert: Howard Livingston - 5/6/2009

Question
QUESTION: Big fan doesnt always come on when air condition is running on outside gas heat and air?  Is this due to the air condition freezing up?  Or what?

ANSWER: That inside fan is turned on, on cooling by the thermostat. You have a digital thermostat ?   May be the problem.

---------- FOLLOW-UP ----------

QUESTION: No digital thermastat. Sometimes I can turn thermastat fan to "on" not automatic and it wont come on.  Sometimes it come on fine.  Its like when the air runs a long time, everything is fine then the fan that blows the air inside stops working but air vents are cold but very little air comeing out.  Then I turn off for several hours and same thing starts all over again.  Like it freezes up and stops working then it thaws and WORKS AGAIN!  Thanks, C~

Answer
Whoa ! A different picture ! It's icing over the evaporator coil, blocking the air flow. Probable cause is low on freon. Or a dirty filter. Or even a clogged evbaporator coil with dirt that has btpassed the filter. Just lack of airflow across the coil. Need a little testing to discover which one it is.