Yeah you need to replace those batteries, doesn't the unit tell you this?
But you replaced the thermostat, that is most likely the source of your headache now.
Did the manufacturer of the thermostats match?
Was it specifically for your setup (there must be a dozen different kinds, between a/c only, heat only, heat pump (w/ and w/out Emheat), and what have you, then there are all the different color wires that have to be connected to the correct spot which is labeled with a letter, and it's all very specific... I mean you can't just hook up red to G because the old thermostat was like that, you have to read the owner's manual of the new one, and slowly make a map on paper of how to re-connect each and every wire, one at a time, and you leave your old thermostat connected until the diagram (and you) is ready...
Most often the method is to replace the thermostat with another from the same mfg!
I didn't say it was easy, I said that is the preferred method.
Sorry if that's bad news but it's one of those picky system things.
Last edited by 8307c4; 11-06-2007 at 01:24 AM.