check all the cooling system lines
i.e.
1)radiator in and out lines
2)pipe spool going to the pump,this section consists of two metal pipes and a rubber hose between them
3)the smaller branch coming out of line mentioned at 2) ,this line provides coolant to the idle air control valve aka iacv ,it consists of three rubber hoses and two metal pipes
4)the rubber hose connected to the other end of iacv
5)the in/out rubber hoses going to the heater inside
iacv is bolted to the butterfly,to see the hoses clearly you have to remove the air assembly
i faced the problem of no coolant in radiator and bottle,hot indicator blinking and i found out after two to three times filling the radiator,that one of the rubber hose attached with the iacv is bursted and coolant is converting into steam,
check also the radiator both upper and lower headers surfaces if any leakage is there ,coolant will create stains there.