Mobile RV Plumbing Leak Detection and Repair Across Florida
A hidden plumbing leak in an RV does more damage per gallon than almost any other failure mode. The water migrates through floor channels, under cabinet bases, and into insulation before it shows on any visible surface. Finding it early is the job.
Water in an RV travels further and faster than in a stick-built home because the floor structure is engineered for lightness rather than leak containment. A PEX fitting that develops a pin-hole drip under a cabinet can introduce water into the sub-floor foam at a rate of a gallon per day without any visible surface moisture for weeks. By the time the owner notices softness underfoot, the foam and the substrate beneath it are already compromised over a larger area than the original source.
Early Signs of a Hidden Water Leak
The clearest early indicator is an unexplained drop in the fresh tank water level when no water has been used. Owners who top off the tank on Sunday and find it noticeably lower on Wednesday without running any fixtures have a leak somewhere in the pressurized supply side. A working demand pump that cycles briefly overnight when nothing is open is the same signal - the system is leaking pressure and the pump is correcting it.
Soft or springy floor sections are a later-stage indicator, meaning water has already been present long enough to degrade the substrate. A musty odor from floor vents or under cabinet doors is the same late signal. Jesse's recommendation is to request a pressure test at the first hint of unexplained water loss rather than waiting for structural symptoms.
What a Water Pressure Test Involves
The pressurization test seals both ends of the fresh water supply system - the tank outlet and all open fixtures - and uses a hand pump to bring the system to 45 PSI. That is within normal operating range and low enough to be safe for all RV plumbing materials. A gauge is attached to the test port and monitored for two minutes. Any measurable pressure drop indicates an active leak; the rate of drop indicates severity.
Once the presence of a leak is confirmed, Jesse isolates sections of the system by closing valves between zones and re-pressurizing each zone separately. The zone that drops locates the leak to a section of the coach. Within that zone, the specific source is found by listening, by visual inspection of accessible fittings, or by moisture detection at floor and wall surfaces. The whole test takes 20-30 minutes.
Pressure Loss When the Pump Is Off
A system that holds pressure while the pump runs but loses it immediately when the pump stops has a leak on the outlet side of the pump's integral check valve. The check valve is designed to hold pressure in the lines when the pump is at rest. If the valve fails or if a fitting downstream is weeping, pressure bleeds back through the pump and the lines go slack. The pump then re-cycles whenever a fixture activates because there is no stored pressure to draw from.
This symptom is frequently misread as a pump problem. The pump is actually working correctly - it is the check valve or the downstream fitting that is failing. Replacing a check valve costs a fraction of a pump replacement and takes 20 minutes.
PEX Fittings in Florida Heat
Push-to-connect PEX fittings - the SharkBite style that requires no tools - are rated to 200 PSI and 200 degrees Fahrenheit, which is far beyond what any RV plumbing system experiences. They are reliable under those conditions. What causes failures in Florida coaches is a different problem: thermal cycling. The fitting is made of CPVC and the pipe is PEX; these materials expand and contract at different rates. Over years of daily temperature swings from 65 to 95 degrees, the grab ring inside the fitting develops micro-play that eventually allows the pipe to creep out slightly under pressure.
The practical solution for Florida-based coaches is to use crimp or clamp PEX connections in high-movement areas - runs near the underbelly where temperature swings are greatest - and reserve push-fit connections for interior runs where temperature is more stable. Jesse assesses the original fitting type when planning any plumbing repair and recommends the appropriate replacement method for the location.
Why Supply Lines Fail More in Summer
Florida summer RV plumbing failures cluster for two reasons: heat and differential pressure from campground systems. Heat causes the polymer in both PEX and the flexible supply hoses at fixtures to soften, which reduces the crush resistance of push-fit connections and increases creep at crimped joints. A fitting that was marginal in May becomes a drip in July.
Campground shore water pressure is the second factor. Many Florida campgrounds deliver water at 80-100 PSI at the hookup pedestal, and a coach without a pressure regulator passes that pressure directly to its fittings. A push-fit connection engineered for RV use at 45-60 PSI will fail faster at 90 PSI, particularly in summer heat. Triton RV Repair installs a pressure regulator as part of every supply-side plumbing repair on coaches that don't have one.
Accessing Lines Behind Walls Without Major Disassembly
Jesse uses a borescope camera through existing gaps, clean-out ports, and plumbing access hatches before cutting any panel. A surprising number of coaches have factory access points that the owner does not know about - removable kick panels under the galley, access hatches behind the toilet base, and cleanout plugs in the underbelly. Finding these takes 10 minutes and avoids cutting panels that are expensive to reconstruct.
When a cut is required - which happens when the leak is confirmed by pressure testing to a section with no factory access - Jesse cuts a clean rectangular panel, addresses the leak, and replaces the panel with matching material and fasteners. The result is structurally sound and nearly invisible. Documenting the panel locations in writing helps the owner plan for future access.
Service Pricing
| Service | Notes | Typical Range |
|---|---|---|
| Service call + pressurization test | System pressurized to 45 PSI; drop indicates active leak; includes trace | $299 - $399 |
| Single joint repair (PEX fitting) | Push-fit or crimp; includes pressure retest | $85 - $195 |
| Multi-joint repair (3-5 connections) | Common after a freeze event or tank removal | $220 - $450 |
| Access panel cut and repair | When leak is behind cabinetry or wall; panel replaced after | $145 - $320 |
| Full under-floor supply line replacement | All PEX from tank to point of use; worst-case scenario | $480 - $1,100 |
Pricing transparency: All prices are estimates based on typical coach configurations. Labor-intensive access situations, custom coach layouts, and parts availability affect the final figure. The service call fee of $299 - $399 covers diagnosis, testing, and the first hour of labor.
Triton RV Repair quotes in writing before any repair begins. There is no charge for a recommendation that the repair is not cost-effective.
Frequently Asked Questions
How do I tell if I have a hidden water leak before the floor goes soft?
The clearest early indicator is an unexplained drop in the fresh tank water level when no water has been used. Owners who top off the tank on Sunday and find it noticeably lower on Wednesday without running any fixtures have a leak somewhere in the pressurized supply side. A working demand pump that cycles briefly overnight when nothing is open is the same signal - the system is leaking pressure and the pump is correcting it.
What does a water pressure test involve for an RV?
The pressurization test seals both ends of the fresh water supply system - the tank outlet and all open fixtures - and uses a hand pump to bring the system to 45 PSI. That is within normal operating range and low enough to be safe for all RV plumbing materials. A gauge is attached to the test port and monitored for two minutes. Any measurable pressure drop indicates an active leak; the rate of drop indicates severity.
Why does my RV lose water pressure when the pump is off?
A system that holds pressure while the pump runs but loses it immediately when the pump stops has a leak on the outlet side of the pump's integral check valve. The check valve is designed to hold pressure in the lines when the pump is at rest. If the valve fails or if a fitting downstream is weeping, pressure bleeds back through the pump and the lines go slack. The pump then re-cycles whenever a fixture activates because there is no stored pressure to draw from.
Are push-to-connect PEX fittings reliable in Florida heat?
Push-to-connect PEX fittings - the SharkBite style that requires no tools - are rated to 200 PSI and 200 degrees Fahrenheit, which is far beyond what any RV plumbing system experiences. They are reliable under those conditions. What causes failures in Florida coaches is a different problem: thermal cycling. The fitting is made of CPVC and the pipe is PEX; these materials expand and contract at different rates. Over years of daily temperature swings from 65 to 95 degrees, the grab ring inside the fitting develops micro-play that eventually allows the pipe to creep out slightly under pressure.
What causes RV supply lines to fail more in summer?
Florida summer RV plumbing failures cluster for two reasons: heat and differential pressure from campground systems. Heat causes the polymer in both PEX and the flexible supply hoses at fixtures to soften, which reduces the crush resistance of push-fit connections and increases creep at crimped joints. A fitting that was marginal in May becomes a drip in July.
Sources and Further Reading
- Uponor PEX pipe specifications - Cross-linked polyethylene thermal expansion coefficients, fitting compatibility, and Florida-climate performance data.
- SharkBite push-fit fitting specifications - Push-to-connect fitting pressure ratings, temperature limits, and inspection procedures.