It's a new unit installed this march, gas company turned off gas for a month. Now gas company turn gas on. Now heater or ac not wrking. When switch to fan on, fan comes on but when unit is switch to heat or ac, no air comes out, nothing happends. Any suggestion or advise? Thank your in advance..

If only the heat was not working I would say you have air in the gas line. Why the ac is not working is a good question. Did you wait for the 5 min delay on the t-stat to kick in??