# RV Plumbing and Tank Repair for San Clemente Owners

> OCRV Center repairs RV fresh water systems, black and gray tanks, water heaters from Suburban, Atwood, Truma and AquaHot, pumps, valves, toilets, showers and LP gas lines. Everything is done in our 35,000 square foot Yorba Linda shop, about 45 minutes north of San Clemente.

**Type:** Repair service  
**Canonical:** https://ocrv.pro/repairs/plumbing-and-tanks  
**Updated:** 2026-07-29

## Summary

We repair fresh water, black and gray systems: pumps, valves, PEX repipe, water heaters, macerators and LP gas leaks. Tank work runs $750 to $8,500.

Water is the most destructive substance that travels inside a recreational vehicle, and the plumbing system is the only one that carries it under pressure through every wall cavity in the coach. A fitting that weeps a teaspoon an hour behind a shower surround does not announce itself. It soaks the luan, swells the substrate, delaminates the sidewall from the inside out and rots the floor at the wall junction. By the time a stain appears on the ceiling or the floor feels soft, the repair is structural.

That is why we take small plumbing complaints seriously. A pump that short cycles overnight, a slightly damp corner in a basement bay, a black tank sensor that reads full after a dump, a water heater that only makes hot water on LP: none of those are emergencies today, and all of them are early signals of something that becomes expensive. We would rather chase down a $400 fitting than rebuild a floor eighteen months later.

San Clemente owners get a partial break here. Hard freezes are rare along the coast from Capistrano Beach through Shorecliffs, so split PEX and cracked low point drains are less common than they are for owners who take the coach to Mammoth or Flagstaff. Freeze damage still shows up in this shop constantly, because it happened on the trip, not in the driveway.

## Where Fresh Water Leaks Actually Come From

Almost every fresh water system in a coach built in the last twenty years is PEX with crimp ring or expansion fittings, and the failures cluster in a short list of places. Crimp rings that were not fully seated at the factory weep under pressure and vibration. Barbed fittings crack at the shoulder from the combination of stress and heat. Shutoff valve bodies split. The city water inlet check valve fails and lets the pump push water back out onto the ground. Hose barbs at the water heater work loose from thermal cycling.

A demand pump that cycles when no tap is open is the single best diagnostic you have as an owner. It means the system cannot hold pressure, which means either a fitting is leaking or a check valve inside the pump has failed. We pressure test the system at a controlled pressure with the pump isolated and watch the gauge. A system that holds is a pump problem. A system that bleeds down is a plumbing problem and we go find it.

Repipe work makes sense on older coaches that keep producing new leaks. When we are opening a wall for the third fitting failure in a season, replacing the run end to end with new PEX and properly made connections costs less than the fourth trip and stops the structural damage clock. We route lines away from exterior wall cavities where we can, which also reduces freeze exposure on mountain trips.

- **Pressure hold test:** The system is pressurized and isolated, then watched on a gauge. A measurable bleed down proves a leak exists before anyone opens a wall, and tells us roughly how large it is.
- **Demand pump and check valve:** Short cycling with all taps closed means lost pressure. Pump internal check valves, pressure switches and accumulator tanks are the usual causes and all are serviceable items.
- **City water inlet and backflow:** A failed inlet check valve lets pump pressure push water back out the fill port. The symptom is a puddle under the coach and a pump that runs constantly on tank water.
- **PEX repipe:** End to end replacement of a failing run with new tubing and properly made crimp or expansion connections, rerouted out of exterior wall cavities wherever the structure allows.
- **Fixtures and shutoffs:** Faucets, shower valves, exterior wash ports and individual shutoffs replaced with serviceable components so the next repair does not require dropping a whole run.

## Black and Gray Tanks, and the Sensors That Almost Always Lie

Holding tanks fail in three ways. They crack, usually at a mounting strap or a seam after the tank has been run heavy over rough road. They separate at a fitting, where the ABS or polyethylene flange meets the drain or vent line. Or the dump valve fails, which is the most common and the least alarming until it happens on a full black tank at a dump station.

Replacement is real work. Tanks live above the underbelly, behind coroplast, and on many coaches they cannot be extracted without dropping the underbelly, removing insulation, disconnecting vent and dump plumbing and sometimes cutting an access panel that will then be properly reframed and sealed. That is why the range on tank work is wide. A gray tank on an accessible travel trailer is a different job from a black tank on a diesel pusher with a full basement.

Level sensors are a separate conversation. External probe sensors on the tank wall read through the material and are reasonably reliable. Internal probe sensors, which is what most coaches have, read through direct contact and are permanently fouled by tissue and residue within a few seasons. A black tank that reads full immediately after a dump is almost never a full tank. We can clean the probes, and when that fails we convert to an external sensor strip that does not touch the contents at all.

- **Tank crack and seam repair:** Polyethylene and ABS tanks are repairable by welding or by bonded patch depending on material and crack location. Strap and support failures get corrected at the same time or the crack returns.
- **Dump valve and cable service:** Blade valves seize, seals harden and pull cables stretch or bind. Replacement is straightforward on accessible valves and involves dropping the underbelly on enclosed coaches.
- **Level sensor conversion:** Internal probes foul permanently and give false full readings. External strip sensors mount on the tank exterior and read through the wall, so residue cannot affect them.
- **Vent line and odor tracing:** Persistent black tank odor inside the coach is usually a blocked roof vent, a failed toilet seal or a dry P trap on the gray side, not a tank that needs more chemical.
- **Macerator and sewer pump:** Macerator units grind and pump waste through a small hose. They clog on wipes and fail on dry running. Replacement is a bolt on job on most installations.

| Line item | Range | Hours |
| --- | --- | --- |
| Macerator and sewer pump replacement | $400 to $1,800 |  |
| Toilet replacement | $300 to $1,500 |  |
| Faucet and fixture replacement | $200 to $800 |  |
| LP, smoke and CO detector replacement | $200 to $600 |  |

## Water Heaters: Suburban, Atwood, Truma and AquaHot

Four platforms cover almost everything we see, and they fail in completely different ways. Suburban units use a steel tank with a sacrificial anode rod, and the anode is the entire maintenance story. When it is consumed, the tank corrodes and eventually perforates, at which point the tank is done. Atwood and Dometic units use an aluminum clad tank with no anode, so there is nothing to consume, but the drain plug threads and the ECO thermostat are the usual failure points.

Truma AquaGo and similar on demand units are a different animal. They heat continuously rather than storing, so the complaints are about flow rate, scale in the heat exchanger and electronic ignition faults rather than tank corrosion. Hard water in inland Orange County builds scale faster than most owners expect, and periodic descaling is part of owning one.

AquaHot and hydronic systems combine domestic hot water and interior heat in one boiler loop, usually diesel fired with an electric element for shore power. They are excellent systems and they are the most involved to service. Diesel burner nozzles coke, the ignition electrodes foul, the circulating pumps fail, and the antifreeze loop needs to be maintained on a schedule. Diagnosis takes longer than on a tank heater and we bill it honestly.

- **Suburban anode rod service:** The anode corrodes so the steel tank does not. Inspect annually and replace when substantially consumed. A neglected anode ends in a perforated tank and a full unit replacement.
- **Atwood and Dometic aluminum tanks:** No anode by design. Failures cluster at the drain plug threads, the ECO limit thermostat, the gas valve and the circuit board rather than at the tank itself.
- **Truma on demand descaling:** Scale in the heat exchanger reduces flow and triggers overheat faults. Periodic descaling with the correct solution restores output without touching the burner assembly.
- **AquaHot burner and loop service:** Nozzle replacement, electrode cleaning and gap setting, circulating pump testing and antifreeze loop condition. The diesel burner needs scheduled attention or it will not light reliably.
- **Electric element and mixing valve:** A unit that heats on LP but not on shore power is usually a failed 120V element or thermostat. Water that is never hot enough is often a mixing valve out of adjustment.

## Finding a Leak You Cannot See and Reading Freeze Damage Correctly

Water travels along the path of least resistance, which means the stain is rarely above the leak. A wet spot at the base of a dinette can originate from a fitting six feet away behind a wall, run along a floor joist and appear where the floor covering finally lets it through. Chasing the stain is how owners end up opening three walls and finding nothing. We work from the pressure side instead.

Our sequence is a pressure hold test to confirm a leak exists, a moisture meter survey to map where the substrate is actually wet rather than where it looks wet, and then targeted access at the highest wet point. On coaches with basement bays we pressurize and inspect from underneath before touching interior finish, because a fitting in an accessible bay is a two hour repair and an interior wall is a two day repair.

Freeze damage reads differently. PEX rarely bursts at the middle of a run. It splits at fittings, at the pump head, in the water heater bypass valves, at the low point drains and inside the water filter housing, because those are the places water sits and cannot expand. When a coach comes in after a cold trip we pressure test the whole system before we replace anything, because the owner usually finds one split and there are three.

- **Moisture meter mapping:** Substrate moisture measured on a grid so we can see the actual wet zone. This is what determines where we open the coach, and it keeps the repair as small as it can be.
- **Access from the basement first:** Anything reachable from an exterior bay gets inspected before interior finish is disturbed. It routinely turns a wall repair into a fitting replacement.
- **Freeze split locations:** Pump heads, bypass valves, low point drains, filter housings and fittings. Water that cannot expand is what splits, so the failures are at the restrictions, not mid run.
- **Substrate and floor evaluation:** Where the leak was long standing, we assess luan, foam core and subfloor condition and tell you honestly whether the plumbing repair alone is going to hold.

## LP Gas Line Service and Why Leak Testing Is Not an Optional Extra

Propane runs the furnace, the water heater, the cooktop, the absorption refrigerator and on some coaches the generator, and it travels through copper, steel and flexible line under the floor and through the frame. It is the one system on the coach where a slow failure has consequences that are not financial. We treat leak testing as a standard part of any plumbing, appliance or heating job, not as an upsell.

The test itself is a manometer test at the system, not a squirt of soapy water on a fitting. We isolate the system, pressurize it and watch the column for a specified period. A system that holds is proven. A system that drops gets traced fitting by fitting with electronic detection and soap solution to find where. Regulator output pressure gets measured and adjusted to specification at the same time, because a regulator out of spec produces yellow flames, sooting and appliances that will not stay lit.

The failure points are consistent. Flexible hoses at the tank and at slide crossings age, crack and harden. Copper line work hardens where it passes through a frame member and eventually fatigues. Fittings loosen from vibration on rough road. Rodents chew rubber hose. Two stage regulators fail on the second stage and produce low pressure that owners blame on the appliance.

- **Manometer hold test:** The system is isolated, pressurized and monitored on a manometer for a specified interval. This is the standard for proving a system is tight and it either passes or it does not.
- **Regulator pressure setting:** Output measured in inches of water column and adjusted to specification. Low pressure causes yellow flames, sooting, pilot outages and appliances that quit under simultaneous load.
- **Flexible hose and slide crossings:** Rubber hose hardens and cracks with age and ultraviolet exposure. Lines crossing into a slide flex thousands of times and are the highest risk section on the coach.
- **Hard line inspection:** Copper and steel runs inspected at frame pass throughs and support points where vibration work hardens the material and fatigue cracks develop.
- **Detector replacement:** LP, smoke and carbon monoxide detectors have expiration dates printed on the housing and stop being reliable after roughly five to seven years. We replace expired units as a safety item.

## Winterization and De-Winterization for Coastal Coaches That Travel Inland

San Clemente does not freeze in any meaningful way, so plenty of local owners skip winterization entirely and are fine. The exposure is the trip, not the driveway. If the coach is going to the eastern Sierra, to Utah, to Arizona high country or anywhere overnight temperatures drop below freezing, the system needs to be protected before it goes, and the low point drains and bypass valves need to be verified working before you rely on them.

Proper winterization is not just pumping antifreeze into a line. We drain the fresh tank and the water heater, bypass the heater so it does not fill with antifreeze, open every low point, run antifreeze through every fixture including the outside shower, the ice maker line and the toilet valve, and pour into every P trap. Missing one exterior wash port is how a $250 service turns into a $2,000 repair.

De-winterization is the other half and it matters more than owners think. Antifreeze needs to be flushed completely, the water heater bypass returned to normal, the anode inspected before the tank refills, the system sanitized, and the whole thing pressure tested before the first trip. Finding a split fitting in the shop in March is much better than finding it at a campsite in April.

- **Complete system winterization:** Tank and heater drained, heater bypassed, every low point opened, antifreeze run through every fixture including exterior ports and ice maker lines, and P traps filled.
- **De-winterization and sanitizing:** Antifreeze flushed out, bypass restored, anode inspected, system sanitized to remove biological growth from storage, then pressure tested before the coach leaves.
- **Bypass and drain verification:** Low point drains and water heater bypass valves seize while unused. If they do not operate, winterization cannot be done correctly, so they get serviced first.
- **Pre-trip pressure check:** A hold test before the first trip of the season finds the fitting that let go over the winter while the coach is still in a bay instead of at a campsite.

## Pricing

| Line item | Range | Hours |
| --- | --- | --- |
| Fresh water plumbing service and repair | $285 to $4,500 | 1 to 18 |
| Black and gray tank repair and replacement | $750 to $8,500 | 5 to 35 |
| Water heater service, Suburban, Atwood, Truma or AquaHot | $350 to $4,500 | 1 to 18 |
| AquaHot and hydronic heat system service | $750 to $8,500 | 3 to 35 |
| Shower, tub and pan replacement | $750 to $5,500 | 4 to 25 |
| LP gas system service and leak repair | $285 to $2,500 | 1 to 10 |
| RV winterization and de-winterization | $250 to $750 |  |

## Process

1. **Intake and symptom mapping** (Day 1). We record where you see water, when it appears, whether the pump cycles and what changed recently. Timing separates a pressure leak from a drain leak from condensation.
2. **Pressure test and moisture survey** (Day 1 to 2). The fresh system is pressurized and watched, LP is manometer tested if relevant, and the suspect area is mapped with a moisture meter. Diagnostic time is $285 per hour, credited against an authorized repair.
3. **Targeted access and findings** (Day 2 to 5). We open from the basement or the least invasive point first, confirm the actual failure and write a line item plan with photographs of what we found.
4. **Repair or component replacement** (Day 3 to 20). Fittings, runs, pumps, valves, tanks, heaters or fixtures replaced. Tank and shower pan work involves dropping underbelly or removing surrounds and takes the longest.
5. **Substrate repair and reseal** (Day 5 to 25). Where water sat long enough to damage luan or subfloor, that gets addressed and every penetration disturbed during the repair is resealed.
6. **Re-test, sanitize and handover** (Final 1 to 2 days). A second pressure hold test, a hot water run at every fixture, an LP test if the system was opened, and a sanitize before the coach goes home.

## What is included

- Systems estimate at $150, credited back against an authorized repair
- Full system pressure hold test with recorded bleed down rate
- Moisture meter mapping of wet substrate before any wall or floor is opened
- Demand pump, pressure switch, accumulator and check valve testing
- PEX repair or end to end repipe with properly made crimp or expansion connections
- Black and gray tank inspection, crack repair, dump valve and level sensor service
- Water heater service on Suburban, Atwood, Truma and AquaHot platforms
- LP system manometer hold test and regulator pressure setting to specification
- Toilet, shower pan, faucet and fixture replacement
- Winterization or de-winterization with sanitizing and a pre-trip pressure check

## Questions

### My water pump keeps cycling when no faucet is open. What does that mean?

The system cannot hold pressure. Either a fitting is leaking somewhere in the coach or the check valve inside the pump head has failed. We isolate the pump and pressurize the system on a gauge. If it holds, the pump is the fault and that is an inexpensive repair. If it bleeds down, there is a leak and we map moisture before opening anything.

### My black tank reads full right after I dump it. Is the tank actually full?

Almost certainly not. Internal probe sensors read by direct contact with the contents, and tissue and residue coat them permanently within a few seasons. Cleaning sometimes recovers them. When it does not, we convert to an external sensor strip mounted on the outside of the tank wall, which reads through the material and cannot be fouled by what is inside.

### What does black or gray tank replacement cost?

Tank repair and replacement runs $750 to $8,500 across five to 35 hours. An accessible gray tank on a travel trailer sits near the bottom. A black tank on a diesel pusher with an enclosed underbelly sits near the top, because the coroplast, insulation and vent plumbing all have to come down and go back correctly. Mechanical labor is $260 per hour.

### Do I need to winterize if I keep my RV in San Clemente?

Not for local storage. The coast does not see the sustained freezing that splits plumbing. The risk is travel. If you are taking the coach to the eastern Sierra, northern Arizona, Utah or anywhere with overnight lows below freezing, the system needs protection before you leave, and the low point drains and heater bypass valves need to be verified working first.

### Will insurance pay for water damage from a plumbing leak?

It depends on the cause and the policy. Sudden and accidental discharge, such as a burst line or a split fitting after a freeze event, is frequently payable. Long term seepage that damaged the floor over two years is usually excluded as wear. We document the failure mechanism and the moisture mapping so your adjuster can evaluate it on evidence rather than assumption.

### How long does a water heater or plumbing repair take?

A water heater element, thermostat or gas valve is often a same week job. A fitting leak that requires opening a wall runs three to seven days once we know where it is. Tank replacement and shower pan work run one to four weeks depending on access and parts. You get a written completion date at authorization and an update if parts move.

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