Posted by Dave on Mar 8th 2026
Why Does My RV Toilet Keep Running Water?
If your RV toilet keeps running water after you flush, the most common cause is a worn water valve. The valve lets fresh water into the bowl when you press the pedal — when it wears out or sticks, it doesn’t shut off completely.
In most cases, replacing the water valve stops the running water and restores normal flushing. It usually takes less than 30 minutes.
| What you notice | Most likely cause | Jump to |
|---|---|---|
| Water keeps flowing even with the pedal fully up | Worn water valve | Water valves |
| Pedal sticks or stays partly down; water stops if you lift it | Pedal not returning | Pedals & springs |
| Valve is crusty or water is slow to shut off | Debris or mineral buildup | Cleaning tips |
Common Symptoms of a Running RV Toilet
- Water keeps flowing into the bowl after flushing
- You hear running water when the pedal isn’t pressed
- The bowl slowly fills with water
- Water only stops if you lift the pedal back up by hand
- Water flow never fully shuts off
These almost always mean the valve is no longer sealing.
What Causes an RV Toilet to Keep Running?
Worn Water Valve
The water valve sits at the back of the toilet and connects to your fresh water supply. Over time its internal rubber parts can:
- Wear out
- Become stiff
- Collect mineral deposits
- Fail to close completely
Replace the RV toilet water valve. Valves are available for most Thetford and Dometic toilets and are inexpensive and easy to install. Find your water valve →
Flush Pedal Not Returning
Sometimes the valve is fine, but the pedal isn’t returning all the way to its resting position — so the valve stays partly open.
Symptoms
- Pedal feels sticky
- Pedal stays partially down
- Water stops if you pull the pedal up
Inspect or replace the flush pedal, pedal return spring cartridge (Dometic), or the cable/linkage and valve return spring (Thetford). Find your pedal parts →
Debris or Mineral Buildup
Hard water deposits or debris can keep the water valve from closing properly.
Cleaning the valve may help temporarily, but replacing it is usually the most reliable long-term fix. Find your water valve →
How to Prevent Water Valve Problems
- Periodically clean off mineral buildup
- Use clean, filtered water when possible
- Avoid harsh chemicals that damage rubber seals
- Check the pedal mechanism regularly for sticking
Find Water Valves & Pedal Parts for Your Toilet
Find your toilet model below — each row links to the matching parts and the full parts diagram for that toilet. Not sure which model you have? Use our Toilet Model Finder or browse all parts diagrams.
Thetford Aqua-Magic Toilets
| Your toilet model | Water valve | Pedal / spring cartridge | Linkage / return spring | Parts diagram |
|---|---|---|---|---|
| Aqua-Magic IV | 13168 $46.99 | 33198 $50.95 | 33315 $30.95 Valve link | IV diagram |
| Aqua-Magic V | 31705 $42.95 | 50545 $51.95 White | 31711 $42.49 Cable kit 36528 $17.19 Valve link |
V diagram |
| Aqua-Magic VI | 31705 $42.95 | 31858 $67.95 White | 31711 $42.49 Cable kit 36528 $17.19 Valve link |
VI diagram |
| Aqua-Magic Style Plus | 34100 $50.49 | 34114 $42.99 White 34115 $56.95 Bone |
34106 $34.99 Cable kit 34110 $19.99 Return spring |
Style Plus diagram |
| Aqua-Magic Style Lite | 34100 $50.49 | 34112 $47.99 White | 34106 $34.99 Cable kit 34110 $19.99 Return spring |
Style Lite diagram |
| Aqua-Magic Style II | 42049 $25.49 | 42067 $52.99 High/White 42068 $52.99 High/Bone 42078 $52.89 Low/White 42079 $53.95 Low/Bone |
— | Style II diagram |
| Aqua-Magic Residence | 42049 $25.49 | 42067 $52.99 High/White 42068 $52.99 High/Bone 42078 $52.89 Low/White 42079 $53.95 Low/Bone |
— | Residence diagram |
| Aqua-Magic Bravura | 31113 $52.99 | 33386 $59.95 Kit 33372 $51.95 Pedal |
— | Bravura diagram |
Dometic / SeaLand Toilets
| Your toilet model | Water valve | Pedal / spring cartridge | Linkage / return spring | Parts diagram |
|---|---|---|---|---|
| Series 300 / 301 | 385311641 $59.95 | — | — | 300 diagram 301 diagram |
| Series 310 / 311 | 385311641 $59.95 | — | — | 310 diagram 311 diagram |
| Series 320 / 321 | 385311641 $59.95 | — | — | 320 diagram 321 diagram |
| Traveler Lite 110 / 210 | 385314349 $56.99 | 385311121 $86.99 White 385311122 $83.99 Bone 385310683 $39.99 Spring cartridge |
— | 110 diagram 210 diagram |
| Traveler Lite 111 | 385314349 $56.99 | 385236096 $52.99 Spring cartridge | — | 111 diagram |
| Traveler 510H | 385314349 $56.99 | 385311121 $86.99 White 385311122 $83.99 Bone 385310683 $39.99 Spring cartridge |
— | 500 Series diagram |
| Traveler 511H / 510+ / 510PS / 511PS | 385314349 $56.99 | 385236096 $52.99 Spring cartridge | — | 500 Series diagram |
| Traveler 2010 / 2011 | 385314349 $56.99 | 385236096 $52.99 Spring cartridge | — | 2000 Series diagram |
| Traveler 910 / 911 / 5010 / 5011 | 385314349 $56.99 | — | — | 900 Series diagram 5000 Series diagram |
| EcoVac 146–149, 157–159, 168 | 385314349 $56.99 | 385310683 $39.99 Spring cartridge | — | — |
| VacuFlush 506–1548 series | 385314349 $56.99 | 385236096 $52.99 Spring cartridge (168–1106) 385310683 $39.99 Spring cartridge (568, 709, 748, 749, 1147, 1148, 1548) |
— | — |
| Concerto 3310 / 4310 / 4410 | 385311545 $129.95 (4300/4400) | — | — | Concerto diagram |
Water Valves
Return Springs & Spring Cartridges
Start with your toilet’s brand and model, check the parts diagram to identify the exact part, or browse by category: