If the flush didn’t banish the odor, it’s time for a hydrogen peroxide shock treatment. This isn’t as intense as it sounds—you’re not defusing a bomb, you’re just giving bacteria a chemical eviction notice. Use standard 3% hydrogen peroxide (the same bottle you keep for scrapes), and pour about one cup per 40 gallons of tank capacity into the inlet pipe.
How to FLUSH a RV Water Heater to Eliminate Sulfur/Rotten Egg Smell
Let it sit in the tank for two hours without using any hot water. This allows the peroxide to bubble through the system, killing the sulfur-producing bacteria where they breed. After the wait, flush the tank again—and you’ll likely notice the smell has vanished like a bad date.
A quick science snack: hydrogen peroxide breaks down into oxygen and water, so it’s environmentally friendly and won’t leave your pipes tasting like a first aid kit. Your water heater just had a spa treatment, and you’re the aesthetician.
