Blow out fresh water system (optional).
Drain sewage tanks.
Drain fresh water tank.
Drain water heater (release prv, remove outside drain plug).
Drain low point drains fresh water lines.
By pass water heater (connect hot and cold water lines together & prevent antifreeze from going into hot water heater).
If water filter is present remove filter and drain container if required.
Disconnect fresh water tank line from water pump & connect temporary water line to pump.
Insert temporary water line from water pump into bottle of antifreeze.
Run water pump and pump antifreeze to all taps hot & cold, toilet. Outside shower & any other items connected to water system.
Ensure that at least 1 full cup of antifreeze goes down each drain.
Blow antifreeze out of system (optional).
Reassemble water pump and fresh water tank.
Return water heater back to normal operational mode.
Note if blowing out trailer with compressed air do not exceed 40 psi.
For trailers without water pump an auxiliary pump must be used and normally connected to the city water conection or kitchen taps and the pumped thru from there.