Fireplace. Customer stated that the fireplace operates normal for about 20 mins and then the fan drops out. The flame continues. The last time the fan dropped out, the fan dropped a few mins later. Fireplace is not used often. After checking the system out, the fan motor itself appears to the the issue. I believe that the motor is overheating and shutting down. This will cause the temp to rise and trip the themosensor. Office to quote replacement of fan motor. System was operating normal for over 15 mins with no issue at this time. Office to follow up. Job complete.