From a post at FR RV Forum here — I follow the US Public Health Service for sanitizing, which I do twice a year.
US Public Health Service
The sanitizing procedure is in conformance with the approved procedures of RVIA and ANSI A119.2 and the U.S. Public Health Service.
Use one of the following methods to determine the amount of common household bleach needed to sanitize the tank:
- Multiply “gallons of tank capacity” by 0.13; the result is the ounces of bleach needed to sanitize the tank.
- The standard solution must have four (4) hours of contact time to disinfect completely. Doubling the solution concentration allows for contact time of one (1) hour.
After I flush the bleached water I add a gallon of white vinegar to the tank, refill and flush again. The vinegar dissipates the bleach smell/taste and the vinegar smell/taste dissipates itself quickly.
Bleach to sanitize, vinegar to descale the water heater.
1/4 cup of bleach per 15 gallons of water in the tank (If you have a 60 gallon tank then that would be 1 cup of bleach). Fill tank partially, add bleach, fill tank the rest of the way. With the pump on and disconnected from city water, run each faucet individually (both hot and cold) until you can smell the bleachy water and then shut it off. Best to do with the water heater in bypass since it doesn’t need to be sanitized and will save water and flushing time.
Take a drive to slosh the water in the tank around.
Let the bleachy water sit in the tank and the lines for a few hours.
Drain the tank. Refill with water. Run each faucet until you can’t smell bleach, if you still smell bleach then drain and fill again, then run water through the lines until the water runs clean.
That’s how I do it, anyway.
2017 GMC Canyon – CCLB, 4×4, 2.8L Duramax, ARE Z-series shell
2013 Shamrock 21SS