How to sanitize an RV fresh water tank, step by step
Last verified: October 29, 2026
Disclosure: Some links on this site may be affiliate links; see our disclosure. We are not affiliated with Jayco or Entegra Coach. Valve names, filter types and water heaters differ by model, so follow your own owner's manual first. The steps below come from a Jayco/Entegra service bulletin on file with NHTSA. [1]
New RV owners see "sanitize, flush and drain" on the delivery sticker and then post on X and the RV forums asking how. Jayco's bulletin says to sanitize the fresh water system when the RV is new, at the beginning and end of each season, and when the water system becomes contaminated or every three months of use. [1]
Before you start: protect the water heater and filters
- Turn off all water heaters and bypass them so sanitizer stays out. On a standard bypass, that's the two supply valves off and the middle valve on. [1]
- Hydronic heaters (Aqua-Hot) are a special case. The bulletin warns that chlorine bleach will damage an Aqua-Hot, that its bypass must be used, and that damage from not bypassing it or not purging bleach isn't warrantable. [1] If you have one, read its manual before you add anything.
- Take the filters out of the loop. Remove the cartridge from any whole-system filter canister and reattach the empty canister, use the bypass tube where a small cartridge filter sits, and turn off the drinking-water valve that feeds the fridge and the kitchen drinking faucet. Chlorine should be kept out of these filters. [1]
Step 1: Drain and close up
Level the RV, drain the fresh water system, then close all low-point drains. [1] Don't have a place to drain? See how to use a dump station.
Step 2: Mix the bleach solution
| Strength | Mix | How much | Contact time |
|---|---|---|---|
| 50 ppm (standard) | 1/4 cup household bleach in 1 gallon of water | 1 gallon of mix per 15 gallons of tank capacity | At least 4 hours |
| 100 ppm (faster) | 1/2 cup household bleach in 1 gallon of water | 1 gallon of mix per 15 gallons of tank capacity | At least 1 hour |
All amounts and times are from the Jayco/Entegra bulletin. [1] Your tank's capacity is in your owner's manual or on the spec sheet for your floorplan.
Step 3: Add it and fill the tank
Pour the solution into the fresh water tank fill, then fill the rest of the tank with fresh water from a hose or the RV's tank-fill setting. [1]
Step 4: Pull it through every line
Turn the pump on. Open each hot and cold faucet one at a time (kitchen, bathroom, shower and outside shower) until water flows steadily and you can smell chlorine, then close them. Turn the pump off. [1]
Step 5: Wait
Leave the solution in the system at least 4 hours at 50 ppm, or at least 1 hour at 100 ppm. Driving a short distance lets the solution splash all sides of the tank. [1]
Step 6: Drain, refill, flush, repeat
- Drain the chlorine solution from the fresh water system. [1] Where you drain it matters; local rules for draining water apply, so check before you open the valve at a campsite.
- Refill the tank with fresh water and run every faucet, including the outside shower, to flush the lines. Keep the water heater bypassed and the drinking-water valve off for now. [1]
- Drain the system again and refill it. [1]
- Chlorine taste won't go away? The bulletin's fix is a flush with one quart of vinegar per five gallons of clean water (water heater bypassed, filters out), run through the faucets until the chlorine smell is gone, then another flush with fresh water. [1]
- Only after the lines are flushed clean: reinstall the filters, turn the drinking-water valve back on, and return the water heater bypass valves to normal (supply valves on, middle valve off). [1]
Related
Putting it away for winter? See how to winterize an RV water system, and in spring, where to dump RV antifreeze.
We don't list sanitizing service prices or recommend products.
Sources
- Jayco / Entegra Coach Bulletin 22-054, Sanitize the Fresh Water System (March 2022), via NHTSA (PDF)
General guidance only. The bulletin was written for specific Jayco and Entegra motorhomes; your RV's valves and filters may differ, so check your owner's manual. Last verified October 29, 2026.