Nights are getting down into the low 20* here in Reno, NV so I just winterized the van. $5.99 gallon of RV antifreeze is good insurance. Two years ago I forgot to run any antifreeze through the hot side of my flat plate heat exchange. well of course It froze and started leaking engine coolant all over my driveway. This was a$365.00 mistake plus engine coolant mess, and that's with no labor.
1.open the drain valve on flat plate heat exchange then run the pump until all water is gone.
2. using a funnel and cut off garden hose I dump 1 gallon RV water system antifreeze into the tank.
3. close drain and run pump until the system stops cycling
4. run hot then cold side of shower hose until water is pink
5. run sink hot then cold until pink
6. open hot and cold side of flat plate heat exchange pink right away.
7. Save lots of money and time, use for beer