Filed Under (Boat/Trailer Maintenance) by Debbie on 17-12-2007

There seems to be a bunch of readers looking for information on boat toilets and holding tanks, indeed there are more people looking for that subject than I ever imagined.  While I’ve talked about problems in marine toilets and I’ve explained how to winterize a head, I haven’t talked about a very basic topic which I find some have recently been looking for help with.  How to pump out the head.

In retrospect, I should have thought about a post on that subject as we too were not sure how to go about it when we first bought Whisper.  As a matter of fact, I called a mobile pump out business and they came to the boat and pumped us out the first time.  I thought it was pretty easy as all I needed to do was pick up the phone and leave a check in the cockpit.

I discovered by looking at the chart of the Columbia River that there are several pump out stations near our club, one is just at the entrance to the club although the owner of the facility is about as surly as they come.  While we were a bit intimidated the first time we did manage to pump out.  So for those of you like us, who haven’t done this before; I’ll explain the process, as I didn’t plan ahead (no pun intended) there are no photos.

Before you arrive at the pump out station walk around the deck and locate the deck cap that identifies the holding tank, it should be somewhere near the head.  Then make sure you have the key to open it with.

Once you’ve arrived at the pump out station tie off the boat to the dock.  This may sound like a stupid thing to say but be sure you’re tied off tightly.  Dock ape idiot, aka hubby tied us off once and didn’t do a good job which ultimately resulted in the bow swinging out from the dock, current against the keel with me holding the pump out hose, not a good position to be in.  Be sure you dock as close to the pump out as possible as the hoses are not all that long.

Once you’re sure the boat is secure, take the key up to the deck cap and carefully open it.  If you suspect the holding tank is extremely full then give it a quarter turn and check for pressure blow off, I’d wear boots to keep any yucky stuff from spraying on me. If you have blow off then pump out sooner you’ve too much in the tank.  Sadly, I don’t know what to do with a too full holding tank other than letting it blow, hopefully in as controlled a condition as possible.  I’d try having someone hold the running pump-out hose at the deck cap to capture as much as possible as you don’t want this going into the water.

Once you can take the cap off, do so carefully.  They generally have a chain inside that keeps them from falling into the water but as we all know Neptune likes to claim things and a deck cap while not as nice a prize as a T-bone steak, is still a prize and a pain in the butt to replace.  If your cap has a broken chain like ours did, you can get a replacement chain at your local marine store and it’s an easy fix.

Once the cap is off find a safe place for the key, remember Neptune is always looking for mischief and while you can buy another key it’s much nicer to spend those bucks on beer.  Step on the dock and get the pump out hose, carefully take the hose to your opening and insert the nozzle firmly, hold it in place the entire time.  Have your helper turn on the pump, there should be a start and a stop button.  Once they’ve turned on the pump (green button), swing the lever (red in the photo) on the nozzle to the open position and pump out until nothing more comes out.  Turn the lever to off and then shut off the pump.

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Your helper should go into the head and pump some water through the toilet to help flush out the line to the holding tank, just incase.  Just remember to keep the hose firmly in the pump out deck fitting until you’ve closed the red lever and turned off the pump.  If there is a water faucet there with a hose, run some water into the tank from the top side.  If you had a blow off then be sure to rinse out the holding tank vent as well, the vent is probably on the top side (side of boat).    If the vent is plugged you won’t be able to pump out at all as there needs to be air flow for the pump out to work.

Once you’ve run some water into the tank, pump out again.  We have a small bucket on a short line that we scoop up some water in so we can rinse the nozzle before we put it away.  After you put the pump out hose away, replace the deck cap and rinse the deck a final time with the bucket of water.

Congrats!  You’ve managed to pump out your boat’s toilet holding tank.  If you have additional advice to assist in this ‘oh so wonderful thing to do’ then please, leave a comment below. 

Read More about ‘problems in marine toilets’ click here

Read More about ‘the perilous potty’ a humorous story about an over full tank click here

Read More about ‘winterizing your boat head’ click here

3 Comments posted on "How to pump out a boat head"
marine toilet problems on May 19th, 2011 at 1:11 pm #

[…] Read more how to pump out your holding tank ‘click here’ […]

Vincent PUlcini on August 13th, 2011 at 11:00 am #

My boat has a manual pump with a through hull water connection for bringing water into the bowl. When pumping out at a dock should the valve to the water inlet be open or closed?

Debbie on August 15th, 2011 at 8:42 am #

When you pump out at a dock you are pumping out the holding tank. It doesn’t matter if the through hull is open or closed.