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Marine Toilet Repair and Maintenance: Common Issues and How to Fix Them

Have you been having issues with your yacht’s sanitation system, especially the marine toilet? Any boat plumbing repair company will tell you this is a normal occurrence caused by an attempt to flush thick, bulky matter through the system or a lack of proper, regular maintenance.

In this article, we list the common problems that marine toilets face and some toilet maintenance tips to ensure smooth sailing.  

How Does a Marine Toilet Work?

Before we delve further into marine toilet repair and maintenance, let’s first review how a marine toilet works.

Traditionally, marine toilets work by flushing the waste into a holding tank to be then emptied onshore. Today, there are less intrusive and cheaper means of storage and disposal.

However, there is a general rule when it comes to sewage and waste disposal on a yacht or any other water vessel. According to the International Convention for the Prevention of Pollution from Ships, fecal matter and wastewater have to be collected in a waste tank onboard. The waste can only be disposed of when your yacht has reached a specific distance from the shore. Generally, no discharge of untreated sewage is allowed within one nautical mile or an island, reef, or the mainland.

a toilet in a private yacht

Types of Marine Toilets

Two basic types of marine toilets include: pump-out toilets and cassette toilets.

Cassette toilets store the waste in portable tanks which then need to be carried to a disposal point on land for emptying. If you opt for a cassette toilet, it’s best to keep spare cassettes on board to avoid situations where you are still miles away from a disposal point but your first tank is already full.

Pump-out toilets offer a more refined experience. They flush the waste into a tank built on-board, which is much bigger than a cassette tank. The tank is then emptied at a specialist pump-out facility using a suction hose. You’ll find companies that provide yacht maintenance in the Philippines that offer this service.

Common Problems that Need Marine Toilet Repair and Maintenance

leaky pipe in a marine bathroom

Water Leaks

Leaks next to the pump handle typically need marine toilet repair and maintenance, especially if they haven’t been serviced for a long time. But don’t worry about the mess it makes as the water that escapes here is the seawater used for the flushing system.

It’s usually easy to fix the leak. The problem typically comes from an old, broken, or perished seal around the rod where the pump handle is attached. To reveal the old seal, you can simply unfasten the plastic nut on top of the pump. You will only need an expert in marine toilet repair when the heads are flushed with salt water, accumulating scale deposits in the discharge hoses. Scale deposits tend to make it harder for you to flush water and allow water in the discharge line to stream back into the bowl.


One of the more difficult marine toilet problems to repair is that of the outlet pipework becoming clogged up with calcium deposits. This is a problem that manifests slowly so it’s easy to not spot the early signs of impaired toilet performance.

As a remedy, try regularly flushing with white vinegar to help slow the build up. The acidic vinegar (which also acts as a mild disinfectant) will dissolve the scale that’s inside the hoses and head. When the vinegar has passed through the marine toilet’s system, flush the lines by pumping a gallon of fresh water through them.

Joker Valves

Without proper marine toilet maintenance, the valves at the exit of the pump can become gummed up with calcium deposits. This will impair their operation to the point that the pump will no longer function properly, making it harder for you to flush away the contents of your toilet bowl.

You can replace the joker valves by using the replacements found in the service kits. If you need assistance, it’s best to seek help from a company that provides yacht repairs and maintenance.

a plunger for the bathroom

Bad Odors

There are two main reasons that cause bad smells in marine toilets. First is that the outlet hoses aren’t of a proper sanitary grade. If regular reinforced plastic hose was used, odors from the inside will transfer eventually to the outside and then to the cabin.

The second possible reason is the result of bacterial breakdown of organic matter in a space that lacks oxygen. This problem manifests itself when you don’t use your yacht often. You can solve this by installing a freshwater flush system or a chemical treatment in the inlet pipe.


This is one of the worst issues to happen but if you invest in regular marine toilet maintenance, there’s no need to worry. In case this happens, don’t use too much force to propel a blockage through your sanitary system.

Over time, most of the blockages will become more flexible and they’ll pass through the sanitary system more easily. In case the blockage doesn’t move, your only solution is to take the pump apart.

a yacht on the ocean

Additional Marine Toilet Maintenance Tips

  • To keep the pump’s smooth operation, follow your once a month vinegar flush with a dose of oil. You can use mineral oil but the best option is a lubricant appropriate for marine toilets.
  • Choose your toilet paper wisely! Many marine toilets can’t handle the luxury quilted paper you find in many stores so it’s best to use cheap, biodegradable toilet paper that’s lightweight. This will help you avoid toilet paper blockages.
  • Opt for a pump-out toilet instead of a cassette one. This ensures a more civilized emptying operation and a better refined marine toilet experience.

For more information and enquiries about marine toilet repair and maintenance, don’t hesitate to reach out to Marine Care today. We are experts in marine yacht plumbing and mechanical maintenance. Our plumbing experts and engineers will recommend the necessary and most efficient solutions and adjustments to ensure your vessel is always running at its best levels.

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