Performing maintenance on 2 2009 carrier air conditioners. Customer mentioned thermostat was blank. Found system showing code 13 for limit lockout. Filter not very dirty. Limit switch stuck closed. Removed limit and loosened to reopen. She said there are some supply vents closed for that system. Let her know to open them, if it get stuck closed again we can replace the limit switch. Customer asking about WiFi smart thermostat. Discussed features with her and showed her options for the t6 pro WiFi for $437 after 10% discount for service club. Also let her know she can purchase her own WiFi stat if she doesnt want to do the t6 pro WiFi. We can install for her $190 after 10% discount for service club. She is going to do some research before making any decisions.