We have a Lennox cb26uh. Replaced the thermostat and the fan would only run in the ON position but temp wouldn't change. On AUTO, nothing happens at all. That lasted for a couple days, now it won't run at all. Is there a breaker or reset of some kind?

Link to thermostat manual?

Out of R, Rc, Rh which terminals were present on the old stat and which on the new?

Are any jumped together?

Did you ever fix the problem