Customer stated that on Sunday tenants called with no heat upon their arrival this morning the boiler was operating, changed set back temp also raised temp at which boiler will come on after satisfied. Allowed time for the boiler to start and shut down normally walked customer through reading the gauge to determine if they have an issue or if the boiler is satisfied with water temp. Unit set to come on when water temp is below 150 and off at 180. No issues found at this time. T775P SERIES 2000 HONEYWELL CONTROLER. Treated as call back since I was here last Friday for a dirty flame sensor.