How do I know if my vacuum flush system needs service?

The main sign is the vacuum pump running by itself between flushes. Others are weak flushing, water draining from the bowl, leaks around the seals and persistent odors.

What does a vacuum flush system seal service include?

We test the system in sections to find the leak, replace worn duckbill valves, bowl seals and gaskets, clean the ball valve, and check that the system builds vacuum and holds it without cycling.

Can a faulty vacuum flush seal damage my boat?

It can. A leaking seal keeps the vacuum pump cycling, which drains the batteries and wears the pump, and leaking waste lines cause odors and damage inside the boat. Replacing worn seals early helps prevent that.

How often should vacuum flush seals be inspected or replaced?

We recommend checking the seals and duckbill valves once a year, and sooner if the vacuum pump runs by itself between flushes, the toilet flushes weakly, or you notice leaks or odors. Boats with heavy use may need checks more often.

Is service required for both manual and electric vacuum flush systems?

Yes. Pedal-flush and push-button VacuFlush toilets depend on the same seals, duckbill valves and vacuum generator, so both need the same checks.

Can vacuum flush system maintenance improve efficiency?

Yes. Good seals keep the vacuum from leaking, so the pump runs less, the toilet flushes properly and odors stay down.

Marine technician wearing gloves replacing the rubber duckbill valves inside a black VacuFlush

Marine technician wearing gloves replacing the rubber duckbill valves inside a black VacuFlush (2)

Vacuum Flush System Seals & Service

Is your vacuum pump cycling in the middle of the night? That means you have a vacuum leak. Our marine toilet repair covers Dometic VacuFlush systems, replacing worn duckbill valves and bowl seals to restore silent, reliable operation.

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$150 /hr

Labor estimate Usually 2–4 hours

Book sends us a ticket; nothing is charged online. Before any work you get a written estimate for labor, parts and the trip fee, and nothing is done without your OK.

Trip fee By distance, one way: $30 in San Pedro, $50 in Long Beach

San Pedro$30
Wilmington, Terminal Island$40
Long Beach: Shoreline, Rainbow Harbor$50
Long Beach Marina, Alamitos Bay$60
Redondo Beach$60
Seal Beach, Huntington Harbour$75
Marina del Rey$85
Newport Beach$110

Farther away: $25 plus $2.50 a mile, one way from our San Pedro shop. No trip fee when the boat comes to our shop, or for plan members. The work of a visit is at least $150; the trip fee is on top.

Registered in California: Breeze Marine Boat Service LLC, San Pedro
Where we work: At your slip from Marina del Rey to Newport Beach, or in our San Pedro shop
Questions first: (213) 693-0224 or submit a ticket

About this service

Vacuum Systems

Stop the
Phantom Cycling.

VacuFlush systems are powerful but sensitive. If your pump runs intermittently, you have a leak. Our VacuFlush repair replaces the critical seals to restore vacuum pressure and silence the pump.

The "Night Cycling"

The most common complaint: the vacuum pump turns on for 30 seconds every 15 minutes. This kills batteries and ruins sleep. It means the system is losing vacuum pressure somewhere.

Duckbill Valves

Inside the pump are four rubber "duckbill" valves. Over time, they stiffen and stay open, preventing a vacuum seal. They are the most common cause of failure, so duckbill valve replacement is due every 3 years.

Bowl Seal Failure

Does water drain out of the toilet bowl even when you haven't flushed? If the bowl goes dry, air enters the system, causing the pump to run continuously. As part of Dometic toilet repair, we replace the seal and ball gaskets.

Diagnostic Protocol.

Finding the leak in a vacuum system.

Isolate

We use vacuum gauges to test the system in sections. Is the leak at the toilet bowl? Or is it downstream at the vacuum generator pump?

Replace Valves

We disassemble the Vacuum Generator (VG) pump, clean the chamber, and install four new Dometic duckbill valves.

Reseal Bowl

We remove the toilet base cover, clean the ball valve, and install a new Teflon and rubber marine toilet seal kit to ensure the bowl holds water.

Vacuum Test

We run the system and verify it builds vacuum quickly (under 60 seconds) and holds it without the pump cycling.

Sealed Tight.

Reliable flushing for extended trips.

Servicing a vacuum generator for a marine toilet system

Installing a new bowl seal on a vacuum flush marine toilet

Dometic / Sealand.

We service Dometic VacuFlush systems, including Sealand toilet troubleshooting.

J-Series Vacuum Generators

S-Series Low Profile Pumps

Maintenance 3-Year Intervals

Common Questions

Why is it cycling?

The vacuum switch senses that the vacuum has dropped and turns the pump on. If the pump runs between flushes, vacuum is escaping, usually through old duckbill valves or a leaking bowl seal.

Can I use a plunger?

Never. Using a plunger on a VacuFlush system will destroy the duckbill valves and possibly damage the vacuum bellows. It requires specialized disassembly to clear clogs.