We have replaced our old thermostat with a Honeywell RTH230 programmable, and it's been over 30 minutes and the a/c has not kicked on. Is there anything that we should check or do?

Re-check your wiring. If the new thermostat has terminals 'Rc' & 'Rh', there should be a jumper between them. If the old t-stat was mechanical and the new one has a 'C' terminal you may have to connect the low-voltage common wire at the indoor unit.

Check your thermostat to insure that it is calling for cool, this thermostat does not use a "c" or common wire but it may not be programed properly, press the mode button to cooling and lower the temperature with up-down arrows. Good luck, Mike