travelnutz wrote:
Using windshield washer fluid which is good for -20 to -30 F in your porti potti flush tank and it never freezes nor does the stuff in the bottom tank as that's where it goes when you flush. Who'd a thunk it?
Washer fluid isn't consistent. The anti-freeze in it is methanol, and the percentage can vary depending on where it's purchased (N vs S), the season, and the brand. +20 F washer fluid contains ~7% methanol, -20 F washer fluid contains ~35% methanol (or ethanol or isopropanol). So, check the temperature rating before relying on it to not freeze - you might not want to use the stuff you bought on sale during the summer.