I have a honewell electronic thermostat which has been in use for about 10 years. It takes two AA batteries. The low battery warning came on, I changed the batteries (tried two separate sets of batteries) and it still shows the low battery warning and the system doesn't work? Any ideas?
Thanks
Rich

Are you putting in the batterys correctly (correct direction)?

Batteries are in correctly. I even tried putting them in backwards and it didn't work.
Do these thermostats have a reset button?

In general, yes. Activated by a paper clip. As to "these" thermostats, there are so many models of gars from say GM as there are from GM.

Model number, or do your own research for a manual.

After replacing the batteries the reset buttton must be depressed.

Did you test your "new batteries" to be sure they aren't run down too?