Mobile RV Toilet and Bathroom Repair Service in Florida
Coast to Coast RV Repair provides mobile toilet & bathroom service service on-site at your campground or driveway across Florida - certified technicians, same-week scheduling.
Coast to Coast RV Repair provides mobile toilet & bathroom service service on-site at your campground or driveway across Florida - certified technicians, same-week scheduling.
Certified technicians. $299 service call. Same-week scheduling. Call (866) 437-4848.
Dometic 310 vs. Thetford Aqua-Magic - Common Failure Modes by Model
The Dometic 310 Series and Thetford Aqua-Magic Residence are the two most common RV toilets across Class A, Class C, and fifth-wheel rigs, and they fail in different ways. The Dometic 310 uses a water-valve ball seal mounted at the base of the ceramic bowl. The seal is a rubber O-ring (part #385311658) that hardens in Florida heat, shrinks, and allows bowl water to drain into the black tank continuously. The Dometic seal kit retails for $18 to $28 and takes 30 minutes to install with the toilet in place. The Thetford Aqua-Magic V and Residence use a blade-style ball valve seal (part #34120 for Aqua-Magic V) that typically fails by cracking along its major axis from the repeated quarter-turn motion of the ball valve.
Floor Flange Leaks and Wax Ring Replacement in RV Toilets
The wax ring seal between the toilet base and the floor flange is a point of failure unique to RV applications because RV frames flex during travel. In an RV, the floor flexes over road imperfections, and over time the wax ring cracks along its circumference, allowing black-tank gases to leak into the bathroom and, in severe cases, allowing small amounts of waste liquid to seep under the toilet base. Signs of a failed wax ring include sewer odor at the toilet base when the ball valve is confirmed sealed, a slight rocking motion of the toilet when you sit, and visible moisture or staining at the floor joint around the toilet base.
Shower Valve and Faucet Service - When to Repair vs. Replace
RV shower valves see more abuse than residential units because they operate on variable pressure and are exposed to temperature swings from cold storage to hot Florida summer bays. The most common failure is a worn cartridge in the mixing valve. On Delta, Moen, and Dura Faucet shower valves commonly installed in Class A and fifth-wheel rigs, the cartridge is a $15 to $45 part that replaces in 20 minutes. Signs of a failed cartridge include hot/cold mixing that requires 3 to 4 full turns of adjustment to find a comfortable temperature, or a handle that feels gritty rather than smooth through its travel.
Also see: Plumbing & Water Services
This page covers toilet & bathroom service specifically. For the full range of plumbing & water services we offer, visit our Plumbing & Water service overview.
Case Study: Thetford Aqua-Magic V toilet (part #42048) - failed ball seal (part #34120 Thetford blade seal kit) allowing the ball valve to seat incompletely, combined with a calcified water valve (solenoid-type, part #42104) that restricted water flow to the bowl to 30 percent of normal and required multiple actuations to build sufficient water for a complete flush
RV: 2018 Winnebago Vista LX 35F • Location: Hillsborough River State Park Campground, Site 88 • City: Thonotosassa (Tampa area)
Symptom: Owner reported the toilet bowl emptying completely within 5 minutes of flushing and a sewer gas odor inside the bathroom when the toilet bowl was dry, with the flush pedal requiring 3 to 4 presses to get sufficient water to start the flush cycle
Diagnosis: Technician poured 2 liters of water into the bowl and timed the drain rate: bowl empty in 4 minutes 38 seconds (acceptable is 20 minutes or more with no flush). Confirmed ball seal failure by feel - the blade seal was visibly cracked and the ball valve did not produce a smooth quarter-turn motion under hand pressure. Measured water flow at the flush valve inlet with a flow cup: 0.4 GPM versus the 1.2 GPM spec for a new Aqua-Magic V valve, confirming the calcified solenoid was the second failure
- Shut off and prepare: Closed the toilet water supply valve at the wall fitting, flushed the bowl empty, and confirmed no water flow with the pedal depressed. Placed a drop cloth and wore nitrile gloves for all subsequent steps
- Remove toilet base: Disconnected the 3/8-inch water supply line at the toilet base using a basin wrench, removed the four floor flange bolts, and lifted the toilet off the floor flange seal - noted partial failure of the floor flange wax ring as well
- Inspect and measure ball seal: Turned the toilet upside down on the drop cloth, removed the ball valve access panel, and extracted the Thetford 34120 blade seal. The seal was cracked through 80 percent of its circumference and hard to the touch - consistent with 6 years of use in Florida heat
- Replace ball seal and water valve: Installed a new Thetford 34120 blade seal kit and the 42104 water solenoid valve (both carried on truck). Reassembled the ball valve assembly, tested the blade seal by filling the bowl to 2 inches and timing - bowl held water for 22 minutes before natural evaporation reduced it below visible level
- Replace floor flange wax ring: Scraped the failed wax from the floor flange and toilet base, installed a new Fernco WR-4 wax ring with integral horn seal, and set the toilet base back onto the flange bolts with new brass nuts tightened to 20 ft-lbs
- Reconnect and test flush cycle: Reconnected the 3/8-inch water supply line, opened the supply valve, and tested five flush cycles - bowl filled to 75 percent capacity with a single pedal press in each cycle, and the ball valve sealed within 1 second of pedal release
- Verify no sewer gas: Poured water into the bowl to confirm the ball seal held, left the bathroom door open for 10 minutes with the owner present - no sewer odor detected.
Outcome: Toilet restored to full function in 2 hours 15 minutes without replacing the full unit - the targeted seal and valve replacement saved the owner approximately $450 versus a full toilet replacement.
Time on-site: 2 hours 15 minutes • Total cost: $385 (parts and labor, including $299 service call) • Dealer alternative: $650 to $1,100 at an authorized service center for a full toilet replacement
“I thought I needed a whole new toilet. The tech opened it up, changed two parts, and it works better than it did when we bought the rig. I really appreciated not being upsold.”
RV Toilet Replacement Models - Specifications and Pricing
| Model | Style | Material | Seal Type | Flush Method | Installed Cost (C2C) |
|---|---|---|---|---|---|
| Dometic 310 Series (302310081) | Standard pedestal | Ceramic bowl, ABS base | O-ring, part 385311658 | Foot pedal, gravity flush | $485 - $685 |
| Dometic 510 Series (302511081) | Low-profile | Ceramic bowl, ABS base | Ball-valve blade seal | Foot pedal, gravity flush | $525 - $725 |
| Thetford Aqua-Magic V (42048) | Standard pedestal | ABS bowl and base | Blade seal, part 34120 | Foot pedal, gravity flush | $385 - $585 |
| Thetford Aqua-Magic Residence (34140) | Residential-height | ABS bowl, ceramic optional | Blade seal, part 42048 | Foot pedal, gravity flush | $465 - $665 |
| Dometic MasterFlush 8700 (9108534907) | Macerator flush | Ceramic bowl | Mechanical seal assembly | Electric macerator pump | $1,150 - $1,650 |
| Thetford Tecma Silence Plus 2G | Macerator flush | Porcelain bowl | Mechanical seal assembly | Electric macerator pump | $1,250 - $1,750 |
Signs You Need Toilet & Bathroom Service
- ✓Ball seal integrity tested by filling bowl to 1.5 inches and timing drain rate - bowl should hold water 20 minutes or more before requiring any seal service
- ✓Flush valve water flow rate measured with a flow cup at the toilet inlet - less than 0.8 GPM on a unit rated for 1.2 GPM indicates a calcified or failing water valve
- ✓Floor flange bolts checked for corrosion and torqued to 20 ft-lbs after any toilet removal - over-tightening cracks the ABS base flange on Thetford units
- ✓Wax ring replaced with a Fernco WR-4 or rubber gasket ring any time the toilet is removed from the floor flange
- ✓Toilet rocking motion tested by pressing down firmly at the bowl rim - any movement indicates a loose floor flange bolt or wax ring failure
- ✓Sewer odor at the toilet base with ball seal confirmed sealed indicates a failed wax ring or cracked floor flange - do not close up without addressing
Toilet & Bathroom Service - Pricing
Typical price range: $185-$685
All calls start with a $299 service-call fee that covers the technician's trip to your location and the first hour of diagnosis. That $299 applies toward any repair you authorize - it is not an additional charge on top of the repair. Pricing shown is a national average range; your exact quote is provided in writing on-site before any work begins.
Toilet & Bathroom Service - Common Questions
Straight answers from our toilet & bathroom service service call log.
My RV toilet bowl drains empty within a few minutes - is that normal?
No. A properly sealed RV toilet should hold water in the bowl for 20 minutes or more under normal conditions. If the bowl drains faster than that, the ball valve seal is failing. On a Dometic 310, that is O-ring part 385311658 - a $18 part we replace in 30 minutes without removing the toilet from the floor.
What is the sewer gas smell in my bathroom even when the toilet is flushed?
The most common cause is a dry ball valve seal that is not fully seated. When the bowl dries out, the seal loses its water barrier and tank gases vent upward through the toilet. Pouring 2 cups of water into the bowl and a tablespoon of vegetable oil is a short-term fix. Long-term fix is replacing the seal if it is cracked or hardened.
Can you replace my factory toilet with a residential-style toilet?
Yes - the Dometic MasterFlush 8700 and Thetford Tecma Silence Plus 2G are macerator-flush units that look and feel close to residential toilets. They require a 12V macerator pump and a 1-inch discharge line to the black tank. The discharge line routing is the variable.
How long does a toilet seal replacement take?
On a Dometic 310 with the standard O-ring seal kit, 30 to 45 minutes with the toilet in place. On a Thetford Aqua-Magic V with the blade seal kit, 45 to 60 minutes including ball valve disassembly. If the toilet needs to come off the floor for a wax ring replacement, add 30 minutes for the full sequence.
My toilet leaks at the base when I flush - what causes that?
Water at the toilet base during a flush means the floor flange seal is failing and flush water is bypassing the seal rather than going into the black tank discharge pipe. Either condition means the toilet needs to come off the floor for a wax ring replacement.
Can you fix my toilet while I am at a campground on a regular site?
Yes - we work at any campground site. We bring our own catch equipment for the toilet removal, we contain everything in a sealed waste bag, and we dispose of it at the campground dump station before we leave.
More Plumbing & Water Services
Other specialized repairs under plumbing & water - all done at your location, no tow required.
Where We Provide Toilet & Bathroom Service in Florida
Coast to Coast RV Repair runs toilet & bathroom service jobs across these cities. Click your closest one for local-specific info, response times, and campground coverage.