I installed a Rheem RGFE modulating furnace and RASL036JEC condenser in the fall. I have a RHC-TST550CMMS communicating thermostat. Everything was OK until I ran the furnace once with the tstat disconnected from the condenser. After that, the tstat has the following message on the bottom of the home screen: "System Configuration Changed!" Everything seemed to work OK this winter, and the air conditioning has come on a couple times this spring. There are no fault codes. I cannot find any information in the tstat or furnace manuals on how to reset/remove this message. Nothing on google. Has anyone encountered this?
The "System Configuration Changed!" message eventually went away, but I'm not sure what caused it to disappear. I had to change the control board on the condenser because it it continually gave a code 09 error, even though the secondary voltage was correct. The "System Configuration Changed!" message disappeared after I changed the board.
But the board had given a code 09 since the day I installed the condenser. It was defective from the manufacturer. Everything worked OK, so I did not change the board until the following summer. The message was not present when I first got the system running, even when the code 09 was present. The message occured after I ran the furnace with the tstat disconnected.
I believe there should be some way to manually cancel the message, but I never found it after an extensive search in the manual and online, and no one replied to my query on the DIY Chatroom.