Water system maintenence

[hrand]

Due to a shortened season, caused by extreme flooding here in the Midwest,, I have decided to not use my freshwater system this year. No advantage to draining, filling, draining, etc. for only a month or so.
But my water heater is still full of the "pink" stuff.
Would it be ok to leave it full, or should I drain the heater?
Thanks

 

[Vic Willman]

If it's an aluminum tank, it'd be best to empty it and leave it dry. If it's a stainless steel tank or a glass-lined steel tank, it'll be OK to leave the anit-freeze inside.

 

[hrand]

Vic,
The tank has an aluminum outer shell, but how can I determine the interior construction?
Thanks