Severe Rust and Corrosion in Heating System

C George

I have a Hydronic heating system in my house that has run straight water for the last five years and now is starting to have erratic problems because of
rust and corrosion on circulators , temp gauges , ect.

I'll admitt that the system was a little grungy after the first boiler ran for twelve years and I have flushed it more than I should have in the last five years , not knowing about the fresh water oxygen.

My question is , If I run 15-20% anti-freeze for corrosion protection , would that be better than straight water. " And not touch it "

Thanks for your feedback