Maintaining your marine toilet effectively

For any boat owners out there experiencing challenges with their marine toilet systems, we are here to help!

Jabsco Toilets & Water SystemsWe have teamed up with the worlds leading supplier of manual and electric toilets for marine use, Jabsco, to produce a simple guide explaining the common problems boat owners are facing when installing and attempting to maintain an on board toilet.


This is a very frequent complaint when it comes to marine toilet installation; the cause of these unwanted odours is very often misunderstood. The 'rotten egg smell' boat owners normally describe it as, is actually caused by anaerobic bacteria (marine life) within the water held inlet pipework, this bacteria is then broken down causing the sulfurous odour. This unpleasant smell occurs more regularly during the summer months when temperatures are higher accelerating the reaction. What happens is when the toilet is initially flushed the contaminated water is released into the air. To prevent this, you can install a strainer in the intake line. 

Another common odour source are leaking connections. Rub the connections with a damp, clean cloth, then sniff it, to locate the leak. You could also check the seal around the piston rod - see whether it needs tightening or replacing.

Yachticon Clean A Tank

Removes calcified deposits in your water tank and system, whilst improving taste and odour. Uses natural citric acid.



Another common complaint is associated with backflow, which is due to the column of water held within the discharge hose. What will often happen is that household bleaches or cleaners will be poured into the bowl in order to clean it, however the chemicals inside these products cause the rubber valves to soften, reducing their performance. It is recommended that you use a Marine Toilet Cleaner for routine cleaning instead.

Another contributing factor comes from the restrictions in pipe work. Acid and scale builds up and narrows the hose diameter, meaning that more pumping power is required in order to overcome this putting a large amount of strain on on the internal valve systems. This can be amended by changing the hose but also prevented by using an appropriate marine toilet cleaner to help reduce any build up. Another point to consider is that if you ensure that enough water is pumped through the system each time it is used, then the build-up within the hose will be minimised.

Anti-syphoning Protection

Another question that regularly arises is related to anti-syphoning protection using vented loops. The answer is pretty simple. When a marine toilet is installed below the water line containing no vented loop there is a high possibility that it could potentially flood, without a vented loop you are only relying on the valve within the toilet to protect it from any water damage. However by fixing a vented loop between the pump and the toilet bowl, the boat is then protected by an air lock system which does not permit any water to syphon through and fill up the bowl, when the pump is operated it breaks the airlock pulling water into the bowl as needed. One important factor to remember is that users should always remember to close their sea cocks when the heads compartments aren't in use.

Jabsco Vented Loop

Use a vented loop for any toilets installed below the waterline to prevent flooding. Essential for most installations.


Upgrading from a manual to an electric flush

Many boat owners are keen to upgrade their manual heads with to electric ones instead. Here are a couple of our picks from our clearance Toilet Outlet...

RM69 Electric Sea Toilet - 12V

Suitable for above or below waterline installations, this toilet features an attractive compact white china bowl, tough white plastic base and pump body and seat.


For the boat owners who have more space a preferred option may be the the Jabsco Designer Flush. This toilet does take up more room however, it provides the user with far more flexibility in regards to bowl size, household styling and water use control.

One good thing is that the base covers the markings left over from the original installation. The Pipework is pretty much exactly the same meaning that the only additional work required is to feed power from your battery to operate the new system. The bowl contains both the inlet and discharge pump making this self-contained unit perfect as an affordable upgrade to the original manual head.

Jabsco Designer Seawater Toilet - 12V

This designer model has an easy-to-clean base. All the pumping and the wiring is concealed in the base. There is a single button flush and water level control switch.


Black tank storage and pump out

Another topic which is regularly asked about marine toilets, is the correct practice for black (holding) tank storage and pump out. Once installed, your head needs the discharge set up. You can pump directly into a holding tank, over board or have a 3-way valve which allows you to choose dependent on where the boat is located at the time. For marinas and inland water areas, pumping directly over-board is restricted, therefore it highly recommended and legally required to have a tank in certain areas where it can be filled up and emptied in the suitable places. In regards to tanks there are a variety of options you can go for; gravity feed discharge, this is where you simply open the sea cock and let the contents drain. However, with this blockages can be a problem and no one ever wants the job of clearing it!

The more common option is to install a macerator or diaphragm discharge pump. This type of pump is positioned near the tank and its primary role is to break up and pump the waste out. A key point when installing either the Jabsco 18590 macerator or the Jabsco 50890 diaphragm waste pump is that these units are designed to push fluid. They are both self-priming but the power is operated  from the discharge side not the inlet. This is why users should ensure they are installed as close to the tank as possible. It is advised that when emptying the tank the user should half fill it with water and pump this through to ensure the pump and pipes are free from any obstructions.

Jabsco Self-Priming Diaphragm Pump

A continously rated motor with thermal overload protection. This pump's multiple diaphragm design allows extended dry running.


SeaSure Macerator Pump

Grinds toilet waste to a uniform slurry for easy transfer and discharge.


Jabsco Diaphragm Waste Pump - 12V

A heavy-duty diaphragm pump that is ideal for emptying holding tanks. It features a straight through non-choke design.


When it comes to purchasing holding tank additives, there are various ones available that help to break down waste to a even textured slurry and also reduces odour that can vent from the tank.

You can also buy special marine toilet paper which dissolves quickly and avoids blockage.

About Jabsco

Jabsco a wide variety of products which suit every type of installation ranging from manual to electric toilets, 3-way diverter valves, vented loops, holding waste pumps, low odour toilet hose and cleaning/treatment additives. They have a distribution network which runs globally ensuing that any necessity for spare parts should be easily accessible.

maintenance products for boatsJabsco have been supplying the World’s leading leisure boat builders with both manual and electric toilets for more than 50 years don't don't hesitate to ask if you have any queries. Products are available for vessels up to approx. 80ft in length.

Jabsco toilets are designed and manufactured especially for marine use. So over the years they have build up a large amount of understanding and knowledge when it comes to the requirements of the marine market. Jabsco are regularly assisting builders with installation advice and solving a lot of problems. Jabsco invest a large amount in research and development ensuring products meet both the functional and aesthetic requirements of the market. Jabsco have an established distribution network worldwide, ensuring local availability of spare parts and technical advice instantly.

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