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HEADS UP HOW DOES MY MARINE HEAD WORK?
When it comes to power boat system questions they come in waves, right now it is marine head questions. How does my marine head work? There are four types of marine heads that production power boats generally install (not one of them will work like your home toilet). At home gravity, a few gallons of water and a siphon effect do the job. With the waste being carried away in large 3 inch pipes. On a power boat things are totally different, there is no gravity or siphon effect and certainly not a 3 inch drain pipe.
Power boats are set up with a Porta Potty, Manual Pump Head, Electric Head or Vacu Flush Head. Each one of these heads represents a completely different way of flushing away waste and have there own unique good and bad characteristics. Only two of these heads are truly interchangeable with out a large amount of additional modification to the vessel. As a matter of fact a Porta Potty does not even qualify as a marine head in some jurisdictions when it pertains to power boat laws.
If your boat has a PORTA POTTY:
A Porta Potty install will mean that your boat is not equipped with either a fresh water system or a waste holding tank (BLACK WATER). This is the most basic head installation that you can have on a power boat. The Porta Potty provides a place to go, however the filling of water for flushing and handling of the waste tank is manual. The Porta Potty latches to the floor with two brackets, one on each side at the bottom of the unit so you can remove and dump the waste. The issue with this is the dumping of this waste, you have to locate a place to do this that is safe and convenient. Some boat owners and manufacturers have manufactured a system where the Porta Potty has been modified. There has been a waste hose attached to the bottom waste holding tank complete with a waste discharge fitting installed on the deck. All of these modifications allow you to pump out the Porta Potty tank at the waste pump station at your local marina.
NOTE: FOR DETAILS ON THIS MODIFICATION CONTACT boatnutmedia@gmail.com REFERANCE/ PORTA POTTY PUMP OUT MODIFICATION
A Porta Potty works with a trap door system where by the waste simply falls into a holding tank on the bottom half of the unit. There is a small water tank on the top half of the toilet so you can pump water into the bowl with the waste, providing a cleaner flush. Porta Potty is an emergency head as far as I am concerned, the holding tank is very small and the system is notorious for odors if you try to use this as a fully operational head.
If you want to upgrade from the Porta Potty set up, you may or may not be able to do this. Any other marine head installation will require a waste holding tank complete with a two inch discharge (flush) hose from the marine head, a water pick up line from the bottom of the hull complete with through hull and a waste tank vent installed in the side of the hull. If your power boat is to small or designed without an area for a small holding tank you maybe out of luck. The other consideration is you must be able to run all the hoses and the through hull valve required to make the head system operational. If you are looking at a boat with only a Porta Potty on board and plan to use the boat in a fashion that would require a more conventional marine head then be sure to have the boat looked at for the possibility of installation before you buy.
A Porta Potty with or without a way to pump out at the dock quite often does not qualify as a marine head in the case of drinking on your boat be sure you know the laws in your region do not assume that as long as you have a porta potty you are legal.
If your boat has a Manual Pump Head:
This will mean that your vessel has a waste holding tank (Black Water) and a through hull in the bottom of the boat for the head to pick up raw (fresh) water to flush the waste away. This style of head has a manual pump to remove the waste and to draw fresh water from the lake, river or ocean to flush. This pump maybe a handle that you move up and down or a upright manual pump that has a handle that you pull up and push down.
This is the most basic and popular complete marine head system. The manual pump head works well and is relatively bullet proof. Most of the designs and makes of heads are completely serviceable, and easy to maintain. Manual flush heads are actually damaged or broken more often than not by the technician or boat owner by over tightening the hardware that holds the pump pieces together. These head pumps are an all plastic body with a ceramic bowl. They are designed to be disassembled for repair, mistakes made when reassembling the plastic pump bodies will lead to cracking at the screws.
Thus creating leaks.
A Manual Flush Head works on a push/ pull system were every pump of the handle is either pulling the waste toward the discharge hose or pushing the waste toward the discharge hose. At the same time you are pulling lake water to the head through the bottom of the boat. Most manual pump heads have a switch located beside the pump handle allowing you the option of a dry flush meaning no lake water is added to the bowl, or a wet flush meaning you are flushing with lake water entering the bowl. This option allows you to flush fluid waste with out the addition of extra water reducing the volume of liquid filling the waste holding tank. This is a genuine concern if you have a small waste holding tank on board. The reason for the popularity of the manual flush head is they will always work, no power is required to operate. More advanced marine head systems require 12 volt power to flush the waste away. No power no flush!
Manual Flush Heads are the easiest marine heads to correct a plugged issue. You must remember that any marine head has a two inch discharge hose and relies on one method or another to push or pull waste from the head to the holding tank. For this reason you should not flush anything but human waste down any marine head. It is important to place a waste basket beside the bowl for paper products or any other waste that could normally be flushed away at home. If you post a sign or purchase a decal that shows what the head will not accept for discharge and educate your guests you will save yourself many head aches and service calls. As a matter of fact technicians will quite often charge a premium to work on a head system, due to the environmental factors that they face in opening up a waste system. Do not use drain cleaners or an auger to clean a plug, use a shop vacuum, complete with running water to flush the system. This way you will not damage components.
If your boat has a Electric Head:
An Electric Head is a swap out for a manual pump head! It will require the installation of a flush switch and a 12 volt circuit to be run to the head. However the head uses the same water pick up and the same discharge hoses. Remember there is no hole under the head for a waste pipe all waste leaves the head through the two inch discharge hose. All of the electrical and mechanical workings off the electric head are part of the toilet itself, at the back of the bowl near the bottom there is a 12volt electric motor that drives a double pump case. The case is divided into two parts the fresh water pump impellor which pumps the water from the lake to the bowl and a macerator with a stainless steel chopper blade to remove the waste. This type of head is extremely efficient at its job, it chops and pumps the waste away quickly.
When it is in action it looks a lot more like the operation of your home toilet than any other head. Of course you must remember that there is a large electric motor and flushing will be far from silent, so night flushes for those sleeping by the head wall can be annoying.
The electric head is a serviceable system, meaning the every once in awhile you will have to service the pump and have a new water pump impellor installed to keep the flushing water at the correct volume. The amount of time between service will depend on the amount the head is used. The worst thing you can do to an electric head is not use it the electric motor will begin to sieze and the water pump impellor can swell or lock up with some of the blades bent over. If the electric motor ever starts to trip the breaker due to lack of use or age you can purchase a new one and should! If you attempt to get a stuck motor going (which you can) it will not last long at all, you will experience problems with the breaker tripping when you flush. You must remember NO POWER NO FLUSH!
If you watch what you flush down the head, maintain and use the electric head regularly it can give you years of uninterrupted service. They really are reliable. If you use you boat for charters or just have a lot of guests this is the head to have. The electric head is very efficient at moving waste down the discharge hose, which may not seem like a big deal, however it is! Waste left in the discharge line for extended periods of time can do two things. One- It can dry out between uses and create narrowing of the hose diameter inside leading to plugs. Two- This is the more important, odor, the waste in the rubber line will eventually leach its odor through the hose material. Once this happens every time you close up the boat and leave for days a time when you return you will have that waste smell lingering in the air. The new white triple wrap waste is line is far and away better than the old black waste line for odor protection. The use of cheap discharge hose on any marine head is a bad mistake.
If your boat has a Vacu Flush Head:
Honestly you have a bucket load of parts between the head and the tank to go wrong. Vacu Flush works with the same size discharge hose as any other marine head. Do not be deceived by that big trap door that opens in the bottom of the bowl. I have had boaters who think that the trap door opens and there is a huge pipe to swallow the waste, not so! The black area you looking at is the bottom of the bowl. When the Vacu Flush system is working right it is awesome, but there are a lot of working parts to make this head function.
First at the bowl, there is a seal on the trap door that must make contact with the bowl opening if this seal is damaged or dries out the system is compromised and the pump that creates the vacuum will keep running (TIP: Keep the trap door covered in a small amount of water this will keep the seal from drying out) Next there is the Vacu Flush pump which is what you will hear running when the head is flushed this pump housing is made up of several key parts. From time to time these parts will need to be replaced. There are at least four duck bill valves split- two on the intake side of the pump and two on the discharge side of the pump, these rubber valves age or get damaged and no longer allow the vacuum to build in the system. Then there is the pump itself the piston that the pump operates is plastic and can crack with time, load and items that are to hard to crush travelling thru the body. If the bellows that seals the piston tight (allowing vacuum to build up) crack the pump will continue to work, if you all of a sudden notice a strong odor of waste one of the first places to check is the pump bellows. As the pump continues to run with the broken bellows there will be raw waste pumped into the area that the pump is located in the bilge. Depending on the year of the Vacu Flush system there maybe a separate vacuum tank and pump location on the vessel. Older tanks are white tanks that resemble a torpedo. The newer systems have the pump and vacuum tank as one unit. On the tank you have a vacuum switch which determines the amount of vacuum created to complete a flush, the amount of vacuum is adjustable. This same switch dictates when the pump is to start up or shut down when the desired vacuum in the system is reached. It is all these working parts that make this system a failure trap if misused or mis installed.
If you are buying a power boat with a Vacu Flush upgrade be sure to tell your surveyor that the system was installed post manufacturer. Quite often when the Vacu Flush is installed after market the runs to the pump are up hill or have to many turns for the Vacu Flush to be reliable. If the installer uses cheap discharge line the system may continually plug.
More so than any other marine head you must be sure that no one is flushing feminine products or hard objects through the Vacu Flush system, this will get very costly to repair. These products along with paper towel will damage the duck bill valves and the pump "no doubt". If your bowl continues to loose water then the seal at the flush door must be replaced. The foot pump flush switch is another area that must be watched. The Vacu Flush head works with the fresh water system of the vessel only. This valve that the foot switch is attached to is plastic, abusive use of the flush pedal will damage it. When this happens the floor of the head can continue to flood as long as the fresh water pump on the boat is left on or you have the vessel connected to active dockside water.
Of all the head systems this one is the one that will plug up the easiest due to the amount of flow restrictions on the way to the holding tank. This head will be as reliable as you treat it!
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