Winterize fail / freeze damage triage

Symptoms

• Pump runs but no pressure, or rapid on/off cycling
• Visible split on exposed PEX, elbows, or fittings after a cold night
• City-water hookup floods under the sink or at the inlet
• Faucet, toilet valve, or shower cartridge cracked
• Tank sensors reading nonsense after a freeze event
• “We winterized” but pink antifreeze never reached a fixture (or clear water still poured out where antifreeze should have)
• Exterior shower, washer box, ice-maker T, or filter housing weeping
• Water heater bypass left wrong; tank or lines took the hit
• Soft floor or ceiling stain after a thaw (intrusion — may look like a roof leak)

Quick checks (owner-safe)

1. Kill the pump and shut the city-water inlet immediately if anything is spraying.
2. Open faucets to relieve pressure; catch water; note which fixtures are dead vs still live.
3. Inspect obvious exposed lines: pump head, filter housings, exterior shower, ice-maker tee, washer box, water-heater connections.
4. If you antifreeze-winterized: verify bypass valve position and whether you actually saw product at each fixture when you did it.
5. Do not keep resetting a pump into a known open rupture — you’ll burn the pump and flood the bay.
6. Photo damage for insurance / shop before tearing out everything. Wide shots of the bay plus close-ups of splits help.
7. If only one zone is wet (e.g. exterior shower) isolate that branch if you have valves — don’t assume the whole coach is lost.

When to stop DIY

• Active spray near electrical panels, converter, fuse boards, or inverter bay — water + power is a hard stop
• Soft floors, wall soft spots, or ceiling stains suggesting prolonged intrusion (also think roof leak lookalikes)
• You cannot locate the feed to a hidden manifold or PEX run inside a slide/underbelly
• Potable-system contamination concerns after improper chemicals (wrong antifreeze type, automotive coolant in potable lines)
• Major underbelly damage, tank splits, or multiple simultaneous ruptures — sectional honesty beats weekend patch stacks
• City water left on while away and the coach flooded — document, shut supply at the pedestal/spigot, Prefer Text

What UMRT diagnoses

Plumbing triage — which zone froze, what’s repairable, and what’s honesty-replace. We don’t guess from one wet spot.

• Which zone froze (pump, manifold, fixtures, tank heaters, exterior branches)
• Repair vs sectional replace vs full re-plumb honesty
• Bypass valve and winterize procedure gaps for next season
• Tank, pump, accumulator, and filter collateral
• Freeze damage vs roof/plumbing leak lookalikes when stains appear after thaw
• Preventative re-winterize scheduling: winterize $175 · trip-prep $225 as separate line items (not bundled silently into a repair invoice)

Trip fee quoted before we roll. Diagnostic $150 applied if you proceed into repair. Labor ~$150/hr. Corridor: MT · WY · ID · WA.

Stop the water first

Order of operations matters more than speed.

1. Pump switch OFF. City-water valve OFF at the coach and at the spigot if hooked up.
2. Open fixtures to drop pressure. Catch what you can — underbelly cardboard or a tote beats a soaked subfloor.
3. If water reached electrical areas: leave breakers that feed wet zones OFF until inspected. Prefer Text if you’re unsure.
4. Do not “test with city pressure” to find the leak. City pressure finds leaks by making them worse.

Only after spray stops do you map damage.

Map what’s still intact vs ruptured

Pump and filters

• Pump runs continuously with faucets closed → open rupture or massive air leak on the suction/pressure side.
• Rapid cycling → often a crack, bad check valve, or accumulator issue after freeze stress.
• Cracked pump head / housing is common after hard freezes — listen for spray at the pump while briefly bumping power only if you’ve already contained water and you’re watching.
• Filter canisters split at the bowl or cap O-ring; replace bowls that crazed in the cold — don’t overtighten a damaged housing.

Fixtures and valves

• Toilet valves, faucet bodies, and exterior shower valves crack at the casting or plastic stem.
• One dead fixture with others live often means a local valve or supply pigtail — not a whole-system condemnation.
• Water heater: confirm bypass position. A tank left in “normal” during antifreeze winterize (or a bypass left wrong during blowout) creates false confidence. Electric element damage from dry fire is a separate mistake — don’t power the element until the tank has water.

Hidden runs and manifolds

• Manifolds in basements, under dinettes, and behind panels are frequent miss points on DIY blowouts.
• Ice-maker, washing machine box, and whole-coach filter loops are classic “we never saw pink there” failures.
• PEX that froze may split along a run you can’t see until you pressurize carefully later — after triage, not during panic.

Sketch the coach: fresh tank → pump → filter → manifold → fixtures → water heater. Mark wet vs dry. That sketch is the repair ticket.

Antifreeze winterize misses vs blowout misses

Two different procedures; two different miss patterns.

Antifreeze (RV potable propylene glycol — pink):

• Bypass wrong → tank or heater never protected the way you think.
• Not enough volume / not run long enough → clear water at a fixture means that branch never got product.
• Low-point drains left open or closed incorrectly.
• Using automotive antifreeze in potable lines is a contamination event — stop, Prefer Text, do not “flush and hope” without a plan.

Blowout (compressed air):

• Regulator set too high risks damage; too low leaves water in traps and low spots.
• Missed branches (exterior shower, toilet, icemaker) leave water that freezes later.
• Water heater tank not drained / bypassed correctly.
• Blowout is not a guarantee in every climate or coach — some owners still antifreeze after blowout for belt-and-suspenders in deep cold. Honesty over dogma.

If you “winterized” but a fixture never showed product or air, that fixture was never winterized.

Freeze damage vs roof / plumbing leak lookalikes

After a thaw, stains appear. Don’t assume roof first or plumbing first — check both patterns.

• Freeze plumbing: wet at lines, fittings, underbelly near PEX, pump bay, specific fixture bases; often tied to a cold night timeline.
• Roof / intrusion: wet at ceiling corners, around vents/AC, window buckles — see roof leak.
• Soft floor near the wet bay can be either. Photo, dry what you can, Prefer Text before you cut large floor sections on a guess.

Related: no water when the pump runs dry or pressure never builds after a freeze event.

Repair plan and next-season prevention

• Replace cracked sections with like materials and proper fittings; temporary clamps are travel-home measures, not permanent corridor fixes.
• After repairs: pressure-check, sanitize potable lines if antifreeze or contamination was involved, verify every fixture.
• Fix the procedure gap: labeled bypass, checklist per fixture, low-point discipline, heater drain/bypass steps written for your coach.
• Tank heaters and enclosed underbelly help — they are not a substitute for winterize when storage goes below freezing.
• Schedule preventative service before the cold snap: winterize $175 as its own line · trip-prep $225 as its own line · trip fee separate.

Water heater, accumulator, and tanks

• Drain plug and anode access on the heater: frozen residual water cracks fittings even when lines were blown.
• Electric element: never energize with an empty tank. Freeze repairs often coincide with dry-fire mistakes during restart.
• Accumulators and check valves crack or stick after ice expansion — symptoms mimic a bad pump.
• Fresh tank itself rarely “explodes,” but fittings, senders, and dump hardware do. Sensor nonsense after freeze: see tank sensors.
• City-water inlet check valve and pressure regulator: common split points when a hose was left connected overnight in a hard freeze.

Insurance, photos, and temporary travel fixes

• Photo wide + close before demolition. Note date/time of the freeze night and whether city water was on.
• Clamp sleeves and temporary tubing can get you to a shop — they are not a finished repair for corridor travel.
• Soft floor: stop injecting water; dry with airflow; Prefer Text before cutting large sections on a guess between plumbing vs roof.

Restart checklist after repairs

1. All valves in normal (non-bypass) positions for use.
2. Fill / prime pump; watch for new spray at every touched joint.
3. Run every fixture hot and cold; verify exterior shower and toilet.
4. Sanitize if antifreeze or contamination was in potable lines — follow potable RV procedures, not “one bleach guess.”
5. Book next-season winterize before storage — $175 line item, trip separate.

Book triage / winterize

Active spray, wet electrical, or a coach you can’t map — Prefer Text. If you’re scheduling ahead of winter, book winterize as preventative, not as an afterthought on a flood call.

Prefer Text (616) 606-5277 · Book a Service · trip fee quoted before roll · diagnostic $150 applied if proceed into repair

Pricing: trip $75/30 mi then $1.50/mi · labor ~$150/hr · diagnostic $150 applied · winterize $175 · trip-prep $225 (separate line items). Credentials (text): Victron Professional Certified Installer · weBoost Authorized Installer · Peplink Certified Associate · Dometic Professional Certified · Starlink install capability. Corridor: MT · WY · ID · WA.

Related guides

• No water
• Roof leak
• Plumbing troubleshooting
• Tank sensor troubleshooting
• Water heater troubleshooting
• Pricing (winterize $175 · trip-prep $225)
• Services · Book a Service
• Troubleshoot hub: /troubleshoot/