Originally Posted by PHILIPHD
What harm does the antifreeze do to the hot water heater if you flush the system with clean water on DE winterizing?
Aside from the anode problems,if you have an anode, it is a bear to get the hot water heater flushed properly. It is much easier to isolate and drain. It takes very little propylene glycol to give odor to the hot water. The other problem is that most systems do not have a check valve so at some point the hot water tank will have pressure above that of the water system and pink flavored water will enter the fresh system. I used to run pink through the hw system but it took luck and at least 5 flushes to get non-contaminated water out.
The heater will drain sufficiently to not be damaged.