Most RV plumbing trouble comes from a few places: fittings that have loosened with road vibration, a toilet seal, a shower drain or faucet, and the water-heater relief valve. A calm search will find the cause quickly; the repair is usually a fitting, a gasket or a bit of sealant.
⚠️ Safety First
- Turn off the water pump and disconnect city water before opening any fitting.
- Let the water heater cool and release pressure before touching the relief valve or the tank.
- Do not use chemical drain cleaners in an RV — they damage seals and tanks.
🧰 Tools & Materials
- Paper towels or a dry rag
- Flashlight
- Adjustable wrench and pliers
- PTFE tape and plumber’s sealant
- Spare hose clamps and push-fit fittings
- Water pressure regulator
📋 Step by Step
1 Locate the leak
Dry everything, then watch.
- Wipe the area dry, then run the pump with the city water disconnected; repeat on city water.
- Lay paper towel under fittings and valves — wet spots show the source.
- A leak only on city water points to the inlet, hose or regulator.
2 Fix fittings and lines
Plastic fittings are easy to overtighten.
- Tighten loose clamps and fittings by hand plus a quarter turn.
- Replace cracked fittings; use PTFE tape on threaded connections only.
- Use a pressure regulator on city water, set to roughly 40–50 psi (275–345 kPa), to protect the plumbing.
3 Deal with the toilet
Most toilet problems are the seal or a clog.
- A slow leak at the base usually means a worn floor seal — replace it.
- For clogs, add water and use RV-safe toilet paper; never force a plunger.
- If the bowl won’t hold water, the blade seal needs cleaning or replacing.
4 Shower, sink and drain
Small gaskets cause most leaks.
- Re-seat or replace the drain gasket and check the P-trap connection.
- For low pressure, clean the faucet aerator and the inline water filter.
5 Water-heater relief valve
A constant drip is a warning.
- An occasional drip while heating is normal as pressure rises.
- If it drips continuously, test the lever; if it keeps leaking, shut off the heater, let it cool, release pressure and replace the valve.
🔧 When to Call a Professional
Stop and book a qualified technician if you see any of these:
- A leaking fresh-water or holding tank
- Leaks inside walls or under the floor you can’t reach
- A water heater that leaks from the tank itself
- Any gas-line work on the water heater
❄️ Frozen plumbing
If lines freeze, thaw them slowly with warm air from a hair dryer — never a torch. Before restoring pressure, look for split fittings and lines, because a thawed split pipe will leak. A heated hose and insulation make winter camping far easier, and our winterizing guide covers storage.
🔎 Plumbing Symptoms and Next Steps
| Symptom | Possible cause | What to do |
|---|---|---|
| Low pressure everywhere | Supply, regulator, filter or pump issue | Compare city water and tank operation |
| One faucet weak | Aerator or fixture blockage | Clean aerator per fixture manual |
| Pump cycles when unused | Leak or pressure switch issue | Shut off pump and inspect for leaks |
| Sewer smell | Dry trap, toilet seal or vent issue | Restore trap water; check seals and vents |
🍁 Troubleshooting in remote areas
Carry basic spares, such as fittings, clamps, tape and a spare water pump fuse. In remote parts of Canada, repairs can be hours away, so practise basic diagnosis before you need it.
📚 More Guides on This Topic
- Low water pressure – diagnose the cause
- Water pump troubleshooting – pump operation and faults
- Preventing and thawing frozen lines – cold-weather problems
- Water leak diagnosis – roof, window and plumbing leaks