Protect PEX, traps, and the water heater before freeze damage turns into spring archaeology. Blow-out vs antifreeze, bypass position, and when mobile winterize makes sense on the corridor.
Active corridor: Montana · Wyoming · Idaho · Washington — case-by-case beyond.
One night below freezing with water still in the lines can split a pipe, crack a water heater tank, or ruin a pump. Here is the full procedure in both directions — winterize for storage, then de-winterize when you roll again. Pair with spring de-winterization and plumbing troubleshooting if something already leaked.
Store the coach where nights drop below freezing. Want a clear blow-out vs antifreeze decision. Need bypass and water-heater drain done without toxic antifreeze mistakes. Prefer a mobile winterize on the MT · WY · ID · WA corridor.
You only need a one-night freeze watch with heat and circulating water — that is trip strategy, not full winterization. You already have active freeze breaks — book plumbing repair first, then winterize what remains.
Two valid methods — do not half-do either one. Many shops combine a careful blow-out with antifreeze in traps and hard-to-drain pockets.
Blow each line at 30–40 PSI max (too high damages fixtures and seals) until no water sputters from every faucet hot and cold, plus toilet and outside shower. Still drain the water heater via the plug/anode — never leave it full.
Use a pump converter kit or siphon hose to pull non-toxic propylene glycol RV antifreeze through the pump. Run every faucet hot and cold until pink appears, then flush the toilet and outside shower the same way. Never push antifreeze through the water heater tank — bypass it and drain the tank separately.
Never use automotive antifreeze (ethylene glycol) in an RV potable system — it is toxic. Only use antifreeze explicitly labeled non-toxic / RV-safe. Missing even one low-point drain or one faucet is enough to crack a line by spring.
Confirm bypass valve position for your exact heater. Wrong position sends antifreeze into the tank or leaves the tank full of water. When unsure, Prefer Text a photo of the valves before you pump.
Do not assume the coach is drinkable until you have checked bypass, flushed pink, and sanitized.
Store lithium around 50–60% SoC; store lead-acid/AGM fully charged on a maintainer. Details: solar & battery.
Cover against UV; move the rig periodically or use cradles/ramps to reduce flat-spotting over long storage.
Inspect before storage — a small failed seal caught in fall is cheaper than a soaked ceiling in spring. See roof troubleshooting.
Close gaps, remove food, and set traps. Chewed PEX and wiring show up as mysterious winter failures.
Owners with a compressor, the correct antifreeze, and a known bypass layout. Photograph valve positions before and after.
You want full winterize or de-winterize done right the first time with a real inspection along the way. Seasonal winterize $175 · trip-prep $225 when quoted for your corridor stop (plus trip fee). We come to you in MT · WY · ID · WA.
Often for mild climates if every line and trap is truly empty. Corridor winters and complex plumbing usually need antifreeze in traps and hard pockets.
Do not gamble. Drain it. Bypass mistakes and cold snaps split tanks.
Keep flushing; sanitize after color and smell are gone. Do not drink until the system is clean.
Trip-prep is a broader go-to-travel check (systems, seals, safety). Winterize is the freeze-protection water job. Ask which quote you need.
Related: Preventive & seasonal · Spring de-winterization · Plumbing service · Plumbing troubleshooting · Fresh-water pump · Troubleshoot hub
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. Seasonal winterize $175 · trip-prep $225 when quoted for your corridor stop.
Credentials (text): Victron Professional Certified Installer · weBoost Authorized Installer · Peplink Certified Associate · Dometic Professional Certified. Starlink = installs only (not a certified partner title).
