I have a 1 month old Rheem mod furnace. During most evenings the furnace runs nearly continuously with very few cycles. However, about once or twice every evening I will near the t-stat click OFF only to turn back ON again after only 30 seconds and then run continuously for a very long time.
Usually this happens when the t-stat shows we're near the setpoint. This caused me to believe it was an issue with the t-stat and not the furnace. However lately I have seen it cycle OFF then immediately ON again while it was doing recovery and about 2 degrees away from setpoint.
Is it possible that this is the furnace causing this and not the t-stat? I thought the t-stat would click ON & OFF without any feedback or influence from the furnace. Is this correct? Or are there things the furnace can do that would cause a t-stat to click like that?
If it is the furnace, shouldn't there be an error code generated on the Rheem's status LED? I tried looking thru the window at the LED and it always reads "0" = OFF or "H" = Heating. If there were a furnace error code related to this cycling, would it be displayed only while the condition existed then clear? Or is there a memory that would hold it so it could be discovered later?