Replacing Your Boat Toilet: A Step-By-Step Guide

Upgrading your boat toilet can make your vessel feel more like a home. Marine toilets come in different shapes and sizes and have different flush mechanisms and tank options, so you can design a system that works for your boat, budget, and cruising plans. Installation may be as simple as swapping out an old toilet for a new model, or it may involve a complete system redesign. This is especially true if you are upgrading from a manual head to a vacuum system.

Manual boat toilets

Selecting the Right Toilet

Before beginning the installation process, it is important to select a toilet that is suitable for your boat and your needs. Consider the size, type, and features of the toilet, as well as any regulatory requirements that may apply.

Preparing the Installation Site

To ensure a successful installation, the mounting surface for the toilet must be flat, rigid, and strong enough to support a person's weight. It should be at least 50mm (2") wider and deeper than the base of the toilet to allow for proper clearance. Make sure there is sufficient space around the toilet for operating the pump and accessing the drain plug.

Re-assembling for Left-Hand Use (If Needed)

If you need to change the pump mounting from right to left-hand, this should be done before installing the toilet. Remove the hose that runs from the pump to the bowl, as well as the screws securing the pump assembly to the base. Lift off the pump assembly and rotate the bowl 180 degrees before re-securing it with the appropriate washers. Then, rotate the pump assembly and the push-fit intake elbow 180 degrees and refit the hose.

Mounting the Toilet

Use the holes in the base of the toilet as a guide to mark the positions for the bolt holes on the mounting surface. Drill vertical holes through the mounting surface and apply a bead of silicone sealant to the outer rim of the bottom base. Secure the toilet by bolting it down and tightening the fastenings.

Through-Hull Fittings

Follow the manufacturer's instructions for installing the seacock, ensuring it is positioned below the waterline when the craft is in motion. If discharging waste overboard, an additional seacock of a specific bore will be required. It is crucial to ensure that all through-hull fittings are properly installed to prevent water from flooding into the boat, which could lead to sinking.

Pipework

Select the correct method for inlet and outlet pipework, depending on whether the toilet is above or below the waterline and how the waste will be discharged. Follow the manufacturer's instructions for securing the hose runs and connections to prevent leaks and ensure that all flexible hoses are secured with stainless steel worm-drive hose clips.

Electric marine toilets

When considering an electric marine toilet, it's important to ensure that your boat has sufficient power to support the toilet's electrical requirements. Most electric marine toilets operate on 12V DC power, which is standard in many boats. However, it's always good to check and ensure compatibility.

One of the key benefits of electric marine toilets is their space efficiency. They are designed to fit into compact spaces, making them ideal for boats with limited bathroom areas. The installation process is typically straightforward, and you can choose from various models with different bowl sizes, such as compact, medium, or large bowls, to best suit your boat's layout.

When installing an electric marine toilet, it's crucial to follow the manufacturer's instructions carefully. Pay close attention to the clearance required around the toilet for comfortable operation and access to the drain plug. Additionally, the mounting surface must be flat, rigid, and strong enough to bear a substantial weight load.

Some popular options for electric marine toilets include the TMC Electric Marine Toilet, which offers a range of features such as clamp-on or threaded-on hose connections, smart flush control, and a heavy-duty macerator pump. The Saniflo SaniMARIN 4 is another comfort-size electric marine toilet option that provides a reliable and sanitary solution for your boating needs.

Vacuum marine toilets

The VacuFlush system operates with fresh water, eliminating the malodours and calcification build-up caused by lake and seawater organisms. It uses an average of a pint of water per flush, allowing up to four times more holding tank capacity than other systems. The vacuum is maintained in the system at all times, and the water level in the bowl can be adjusted by lifting the flush lever.

When the toilet is flushed, the vacuum energy stored in the system is released by pushing down on the foot lever. This change in pressure activates the vacuum pump, clearing the bowl and pushing the waste into the holding tank at a rapid speed of 7 feet per second. Once the flush lever is released, a vacuum-tight seal is created at the toilet bowl, and the vacuum pump continues to run until the vacuum level is recharged, which typically takes about a minute.

The VacuFlush comes in a variety of sizes and footprints, including low-profile and residential options. It offers different discharge types to cater to the specific needs of your boat. The 5000 Series is the most popular, providing above and below floor discharge options and three height choices. The 4800 Series features an all-ceramic toilet and a flush panel, while the 4700 Series offers a flush handle for a household look.

Composting toilets

Installation

The process of installing a composting toilet will vary depending on the make and model of the toilet, as well as the specific setup of your boat. However, here is a general overview of the steps involved:

• Remove the old toilet: Unbolt the base of the old toilet and remove any pipes or networks connected to it.
• Repair any water damage: Identify and fix any water damage caused by the old toilet, such as rot or condensation issues. Ensure that the mounting surface is flat, rigid, and strong enough to support the weight of the new toilet.
• Prepare the new toilet: Follow the manufacturer's instructions to assemble the composting toilet, if necessary. This may include adding a composting medium such as coconut coir or peat moss.
• Install the new toilet: Place the new toilet in the desired location, ensuring that it has sufficient clearance and that the seat can swing up without hitting any obstacles. Secure the toilet to the mounting surface using bolts and washers.
• Connect the vent hose: Composting toilets typically use a fan system to control odours. Connect the vent hose to an appropriate outlet, such as an old pump-out port. Ensure the fan is wired into your boat's electrical system and test it to make sure it is working.
• Test the toilet: Once the toilet is installed, test it to ensure it functions properly. This includes checking that the fan is running, the trap door opens and closes smoothly, and that all waste is directed into the appropriate containers.

Maintenance

• Emptying the liquid and solid waste containers: The frequency of emptying will depend on usage, but it is recommended to empty the liquid container daily and the solid container every 8-10 days or when it becomes full.
• Stirring the compost: To promote decomposition, stir the compost after each use.
• Wiping down the toilet: Keep the toilet clean by wiping it down after each use.
• Spraying diluted vinegar: Spraying diluted vinegar onto the toilet every few days can help to control odours and maintain cleanliness.
• Changing the composting medium: The composting medium (e.g. coconut coir) should be changed regularly to prevent it from becoming too wet or foul-smelling. The exact frequency will depend on usage and the specific medium used.
• Dealing with insects: Insects can sometimes be attracted to the waste. To mitigate this, use products such as diatomaceous earth or Rid-X Septic Tank Treatment Packs to deter insects and break down waste more quickly.

Benefits of Composting Toilets

• Eco-sustainability: They do not discharge waste into the sea, which is more environmentally friendly.
• Odour control: The combination of the fan system and composting medium effectively controls odours.
• Easy installation and maintenance: Composting toilets are typically easier to install and require less maintenance than traditional boat toilets.
• Regulation compliance: Composting toilets, such as the Air Head model, comply with international regulations, allowing you to travel worldwide.
• Space-saving: Composting toilets do not require holding tanks or extensive pipework, freeing up space on your boat.
• Reliability: Traditional boat toilets can suffer from blockages and critical part failures. Composting toilets do not have these issues, providing simple and reliable waste management.

Installation instructions

The Jabsco Manual Marine Toilet can be installed in both power and sailing craft, either above or below the waterline, for use on the sea, river, lake or canal. The waste can be discharged overboard (if national and local regulations allow it), into a treatment system, or into an onboard holding tank.

The toilet is delivered assembled for right-handed operation. If you wish, the pump mounting can be changed from right to left-hand operation. To do this, first pull off the hose that runs from the pump to the bowl. Then, remove the four screws that secure the pump assembly to the base. Leave the base valve gasket on its three locating pegs. Remove the four bolts that secure the bowl to the base. Rotate the bowl 180 degrees and re-secure it, using the nylon washers to protect the ceramic from the stainless steel washers and nuts. Rotate the pump assembly 180 degrees and re-secure it. Rotate the push-fit intake elbow 180 degrees and refit the hose between the pump and the bowl.

Select a location that will give sufficient clearance all around and above the toilet. Ensure there is room to operate the pump and access the drain plug at the end of the base. The mounting surface must be flat, rigid, and strong enough to support a man's weight. It should be at least 50mm (2") wider and 50mm (2") deeper than the base of the toilet. There needs to be sufficient clearance below the mounting surface to be able to secure the mounting bolts. The seat and lid should be able to swing up and over at least 110 degrees, so that they will not fall forward when the craft heels or pitches.

You will need the following:

• 4 x 8mm (5/16") diameter stainless steel bolts of the length to suit the thickness of the mounting surface.
• 4 stainless steel nuts, preferably self-locking. If you do not use self-locking nuts, you will need some nut-locking compound.
• 8 large stainless steel washers not more than 21mm (13/16") diameter.
• A small tube of white silicone sealant.

Offer up the toilet in the selected position and, using the holes in the base as a guide, mark the positions for the four bolt holes on the mounting surface. Remove the toilet and drill four vertical holes of 9mm diameter through the mounting surface. Apply a bead of white silicone sealant to the outer rim of the bottom base. Bolt down the toilet and tighten the fastenings securely. If you are not using self-locking nuts, use nut-locking compound.

Through-Hull Fittings

You will need a 19mm (3/4") bore seacock for the flushing water inlet, and, if you are discharging the waste overboard, a 38mm (1.5") bore seacock for the waste outlet. Follow the seacock manufacturer's instructions concerning materials and methods of installation. Ensure the inlet seacock is positioned where it will be below the waterline at all times when the craft is underway, and also ensure that any outlet seacock is both aft of, and higher than, the inlet seacock.

Frequently asked questions