Right place if you
Are commissioning a coach after winter, inherited a tank of unknown history, or keep getting plastic/musty taste even after filter changes.
Water · plumbing
RV fresh water tank sanitizing
Worth doing at the start of every season, after storage, or any time the tank sat with stagnant water. The goal is a clean system you will actually drink from — not a chemistry experiment.
Active corridor: Montana · Wyoming · Idaho · Washington — case-by-case beyond.
Field notes
On MT · WY · ID · WA legs, owners often fill from mixed city and well sources, then park for weeks. Biofilm and chlorine taste build quietly. Sanitizing is a scheduled chore, not a panic response to a weird smell.
Who this is for
Maybe not yet if
You need pump priming or cycling — see fresh water pump. Black/gray odor is a different system — see holding tank sanitation.
Safety and dilution basics
Household chlorine bleach (unscented, no detergents) is the common field method. Typical guidance is about one-quarter cup of bleach per 15 gallons of tank capacity — mix bleach into a jug of water first, then pour into the empty fresh tank so you never dump concentrated bleach onto fittings. Wear eye protection; ventilate the bay; keep pets and kids clear. Do not mix bleach with ammonia or other cleaners. If your manufacturer specifies a different ratio or product, follow the label for your tank material.
What bleach does
It oxidizes bacteria and biofilm on tank walls and in lines when you circulate it through every faucet and fixture.
What it does not
It will not fix a cracked tank, a fouled pump strainer, or city water that needs filtration at the fill — see filtration.
Flush cycle checklist
- Drain the fresh tank completely; bypass or remove inline filters you do not want to chlorinate (check cartridge maker guidance)
- Add diluted bleach solution to the empty tank, then fill with potable water
- Open each cold and hot faucet (including outdoor shower and toilet fill if present) until you smell chlorine at every outlet; run the water heater if it is in the loop and safe to do so per your manual
- Let the solution sit — commonly several hours; overnight is fine when you are parked securely
- Drain tank and lines; refill with fresh water; flush until chlorine smell is gone (may take two or more fill/drain cycles)
- Reinstall filters; taste-test cold water before cooking or drinking
Taste and odor after sanitizing
Residual chlorine
Extra flush cycles and a fresh carbon filter usually clear it. Do not “fix” taste with scented cleaners.
Plastic or musty linger
Often biofilm still in a hose or water heater. Repeat a careful cycle; inspect fill hose and pump inlet strainer.
City vs well fills
Well water with iron or sulfur can smell after sitting even in a clean tank — filtration helps; sanitizing alone may not.
When to stop DIY
Persistent contamination after two proper cycles, or any leak/odor of bleach outside the plumbing — Prefer Text with photos and tank size.
DIY vs Prefer Text
Reasonable DIY
Seasonal sanitize, hose and strainer inspection, filter changes on a schedule.
Book us when
You need a winterize / trip-prep visit (seasonal canon: winterize $175 / trip-prep $225 as separate line items when booked), pump or heater work, or a coach that will not clear odor. Prefer Text location and what you already tried.
FAQ
How often?
Start of season, after long storage, or when taste/odor returns — more often if you fill from unknown sources.
Can I use tablets instead of bleach?
Some RV-labeled sanitizers work; follow their dose. Avoid mystery “miracle” additives with no dilution instructions.
Will this hurt my pump?
Brief, properly diluted chlorine circulation is common practice; prolonged high concentration and dry running are the real enemies.
What does a visit cost?
Trip $75 within 30 miles then $1.50/mi each way; labor ~$150/hr with 1-hour minimum / 30-minute increments. Prefer Text for a quote on your setup.
Related: Water filtration · Fresh water pump · Holding tank sanitation · Services
Pricing teaser
Trip fee $75 within 30 miles, then $1.50/mi each way. Labor ~$150/hr (1-hour minimum, billed in 30-minute increments). Diagnostic $175 applied toward repair if you proceed.
Credentials (text): Victron Professional Certified Installer · weBoost Authorized Installer · Peplink Certified Associate · Dometic Professional Certified. Starlink = installs only (not a certified partner title).