Marine Toilets and Pumps
The disposal of a boat’s waste water is regulated by The International Convention for the Prevention of Pollution from Ships (MARPOL). Feces and waste water have to be collected in a designated tank on board and can only be disposed of once the vessel has reached a certain distance to the coast.
A disposal on inland waters as well as in some regions is strictly prohibited. In this case, the tank contents have to be disposed of via a designated vacuum sewerage system in the harbor.
On-board toilets cannot really be compared to regular household toilets. Handling and function of these toilets can be very particular. There are two types of toilets on yachts—manual toilets and electric toilets.
Manual On-Board Toilets
These types of on-board toilets come without the familiar flushing system. A hand pump,
which is located on the side of the toilet, pumps rinse water into the toilet bowl while completely
draining the contents of the toilet by means of
a switch valve.
The advantage of a manual on-board toilet is the low cost in purchasing the toilet as well as maintaining it. You save electricity and money for spare parts. These toilets are extremely reliable, provided they are serviced regularly.
A disadvantage of a manual toilet is its complex operation. This can especially lead to problems on charter yachts and when small children are on board. Water usage is rather unmanageable, which can also be an issue in combination with small sewage tanks. Often the pump is engaged too many times and too much water is flushed, due to which the tank is filled quickly. The seals and valves inside the manual pump have to be serviced and greased regularly. These toilets tend to clog easily.
Electric On-Board Toilets
As far as electric on-board toilets are concerned, different models are available, from the simple entry-level model to the comfort version.
The Latest Technology:
Electric on-board toilets with a large macerator diameter of 80 to 120 mm in combination with a very quiet engine. The noise production is comparable to a regular household toilet. Water consumption for these on-board toilets is between 1.5 and 3.5 liters per use. Use with a sewage tank is also no problem.
On-board toilets with base pump (for example SVB item number 76893). The pumps installed inside these toilets are macerator and impeller pump in one. The noise produced by these kinds of pumps can be extreme at times.
Like at Home:
This type of on-board toilet (for example SVB item number 13500) comes with the pump installed inside the toilet bowl, and it is possible to add extra insulation. Energy and water consumption depends on the flushing duration. The flushing time, in turn, is determined by how long the flush button is held down.
Electric Conversion Kits for Manual On-Board Toilets
Many manufacturers of on-board toilets offer the possibility to convert your manual on-board toilet into an electric system with corresponding conversion kits. Either the hand pump is completely replaced or an addition is installed on the bottom.
For both variants, combined macerator/impeller pumps are used and a cumbersome switching between flushing and draining is eliminated.
For excellent flushing results of your on-board toilet, the following should be taken into consideration:
- Ensure a sufficient supply of fresh water to the pump or the central on-board pressure water systems.
- Invest in a good waste water pump that can transport a lot of water and comes with a good macerator for feces and toilet paper. This will ensure that waste water and feces pipes do not clog.
- Always choose large waste water pipes and install these, if possible, without angles or only with sufficiently dimensioned angles. Ideally, the bowl shape should already have a slight gradient, from which the hoses go straight and at a slight inclination into the sewage tank. This way, solid parts cannot get stuck inside the corners of the pipes.
- Use a check valve in order to ensure that drained water does not flow back into the toilet.
When installing an on-board toilet below the water line of your boat with a connection to a thru-hull for waste water disposal toward the outside, water can flow back into the toilet due to the siphon effect. In a swell or when the boat is heeling, the water can leak from the toilet.
In order to avoid this, we recommend installing a gooseneck valve for ventilation between the rear of the toilet bowl and the pump. Make sure that the ventilated gooseneck valve is at least 15-20 cm above the water line in all heeling and trim positions of your boat. With this installation, the drain hose should be as close as possible to the toilet and should loop upward.
Sewage pumps are also known as waste water or gray water pumps. The pump takes care of draining the waste water from the toilet. There are two types of sewage pumps—self-priming and impeller pumps, the bucket wheel of the latter powers the movement of the liquid.
The quality of sewage pumps varies greatly. When choosing a pump, you should definitely keep in mind the required discharge head and the output. The material of the impeller as well as the installed cutting mechanism/macerator can be significant as well and up to what height the pump is self-priming. The following table is a comparison of the pumps that are sold by SVB with regard to these important features:
|Max. output l/h||Current draw||Self-priming up to||Discharge head up to||Other features|
|MATRO Sewage Pump with Macerator||1380 up to 3m, 2580 l/h up to 4m||12V/12A or 24V/6A||60 cm dry, 3 m wet||5m||Pump head made of seawater- and feces-resistant bronze alloy|
|JABSCO Sewage Pump Type 12GPM||2760||12V/16A or 24V/8A||ca. 1.2 m dry ca. 1.5 m wet||6m||Dry-run protection turns off pump if necessary and prevents damage to the impeller. Stainless steel macerator with 4 blades|
|JABSCO Sewage Pump||1140||12V/8A or 24V/2.5A||approx. 3 m dry||-||Compact construction, flexible installation due to 360° rotating connections, dry-run protection|
|RM69 Sewage & Bilge Pump||2400||12V/16A or 24V/10A||3 m||5 m||With 2-way valve also for combined pumping of bilge and sewage tanks|
|RHEINSTROM Sewage Pump Type F||4200||12V/40A or 24V/20A||-||5 m||Not self-priming, has to be installed at the lowest spot of the tank or lower than the tank|
Spare Parts for Marine Toilets and Sewage Pumps
A large selection of accessories and spare parts for marine toilets can be purchased online. From spare pumps to toilet seats and lids as well as seals, we always carry the most important parts in stock. If you ever need a part that is not available in our online shop, please contact our customer service. We will gladly assist you.
Simply provide us with the parts number of the spare part, as can be found in the operating manual for the product. If you no longer have the operating manual, you can find the same on our website on the relevant product page. In case you are not sure which model toilet is installed on your boat (e.g. purchase of used boats), you can send us an email with a photo of your toilet, any name plates as well as of the spare part that you are looking for.
We also carry a large selection of accessories for sewage pumps and other pumps. Suitable spare impellers, service kits and much more can be found here.
Would you like to know which sewage hose is suitable for your on-board toilet? Consult our handy Guide to Boat Hoses.