Just noticed the thermostat said low Bat after the house warmed up. Changed batteries and now display is fine but when it clicks on the a/c nothing happens.:( Any help appreciated.

Check your fuses out side to see they blew does the blower come on when you switch the thermostat to fan on?

Actually it wasn't anything major. We went and replaced the thermostat thinking that was the problem and it still didn't work. Turns out when my husband replaced the filter this weekend the cover wasn't on exactly right so after just tapping against it it turned back on.