BR1500G Fan fault & loud Humming noise

[Anonymous user]

hi, i have error code F08 displayed on the LCD which indicating fan fault,but the fan is running properly and i can feel  a constant airflow on the front ,this happens exactly 4 min after i turn ON the unit even with utility power connected as well as disconnected , no load on the ups,running power chute self-test is success but the fault only displays on the lcd and turns OFF the out put and so the equipments connected looses power abruptly,so i was thinking to disable the automatic self test as everything is fine on inspecting but just dont know how do i perform the procedure.

secondly when the utility power is disconnected or battery backup is ON the humming noise from a transformer is so loud it started to have just befor 3-5 days only, previously it was quiet except for the fan noise. and is there a way to wirelessly monitor the ups by connecting it to router or something because once in a month i had to change replace battery date from powerchute or this unit will show low remaining time even if the battery is full and no load is connected and turn off there is some serious calibration with these model this is my 3rd unit which was RMA'd , am only using the ups to power cctv and cameras which is only about 50W.