Waste pump problems

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folieadeux

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I took my (new to me) 2006 Meridian 391 a few miles off-shore yesterday into a legal discharge zone to dump my waste tank for the first time. Nothing will pump out from the tank. I have the seacock open and when I open the engine hatch in the salon, I can hear the pump working, but nothing is moving. I have the macerator switch turned on and I am holding both "discharge" switches, but no movement.

Before I start tearing apart the hoses, any suggestions that may be simple that I am missing? The vessel has a vacu-flush toilet.
 
you likely have a whale gusher overboard discharge pump. they have duck bill valves in them just like the vacuuflush generator does. if the pump does not smell when you are using it the diaphram is probably not broken. pull the hoses off the pump and clean up the duckbill valves. if they are in bad shape just replace them. assuming you don't have a blocked vent line you should be fine. FYI, i've found that there is not enough head pressure on the pump to use it while the boat is moving at any speed. another trick i've learned here is to flush a gallon of white vinigar down the heads and let that sit to clean up the mineral deposits on the valves. it seems to help.
 
we need to know what kind of pump/macerator you have... and make sure that you dont' have a shut off valve on the hose to the pump where it connects to the tank. some boats have it when the hose is at the bottom of the tank, instead of using a dip tube at the top.

also, some boats have only one pick up/discharge hose out of the tank with a Y valve to select pump out or overboard macerator. trace the hose to see if you have one.

if you have one of the Jabsco impeller type macerator, dont' waste any time with that POS, throw it out of there and install a Sealand bellow pump. it will be the last time you have to worry about it.
 
Vic, since you mentioned the "s" word (SMELL), the boat does it a bad odor in the cockpit when the vacu-flush toilet is flushed. Can that be caused by bad duckbill valves. Sometimes when sitting in the salon at night, I can hear the toilet pump working without being flushed.
 
if you get a smell outside when you flush, it's either that you dont' have a charcoal filter on the vent line or that it needs to be replaced. that has nothing to do with the DBs...

now, if the VF pump kicks in once in a while, it could be bad DBs. on a 2006 boat, they're liekly to be original and 4 ot 5 years is typically about as long as they last. they're easy to replace... jsut flush a few times to rinse, unclamp the hoses on the inlet and outlet of the vac pump, ujnscrew the fittings and replace. make sure you put them in facing the right way... teh VF pump has 4 DBs... the bellow discharge pump has only two.

now if water doens't stay in the bowl, it will also make the pumps run once in a while, if that's the case the problem is dirt in the bowl seal or worn seal.
 
Pascal

Water stays in the bowl after flushing.

I just checked the owners' manual and the diagram shows a charcoal filter. I will pull that filter and replace it. Sounds like I need to replace the DB's and filter.
 
the filter yes, the DBs maybe not although again if they're original they're due... if it just kicks in every hour or more, it's not a big deal. sometimes flushing some water thru will clear them.

when you install new DB, put some liquid soap on the flange where the DB sits, this helps making sure they don't get distorded when you reassemble the fitting
 
If the filter is plugged-up, you won't be able to pump out the holding tank. Air must be able to come into the tank, for the pump to be able to pump it out.
 
quote:
Originally posted by Vic Willman

If the filter is plugged-up, you won't be able to pump out the holding tank. Air must be able to come into the tank, for the pump to be able to pump it out.
Click to expand...


That would be the filter in the vent hose, right?

Not all boats have a filter in the vent hose but the vent or vent hose can become plugged. Overfilling the tank is one way to do it. Also, insects may build a nest in the thru hull for the vent. And if there's a screen on the vent fittin, it can corrode and become blocked. You don't need a screen, pull it out and discard it.
 
I have a SeaLand brand of pump I have searched everywhere and I can not locate a "slot for a screw driver". Where is this slot? When I turn on the discharge pump, I can see a large piston type of pump moving up & down trying to move waste out of the tank.

Yesterday I disconnected the discharge hose that goes to the seacock in the bilge and placed a bucket under the discharge hose when I turned on the macerator discharge pump, I got about 1 gallon of waste in 15 minutes, very slow output and I doubt the pump has enough pressure to force the waste thru the seacock.

Where are the "duckbills" located? Several of you have made reference to the "duck bills" but before I disconnect all the hoses on top of the tank, I would like to have some idea where I am headed.

In frustration, I took my boat to a marina with a pump-out station and when the pump-out hose is connected to the deck fitting, the pump-out would function for about 2 minutes and then the suction would be lost. This happened about 10 times. I finally gave up. Someone has mentioned the charcoal filter can effect the pump-out function, what's up with that.
 
Yes a cloged filter will affect pump out, think about it it s logic. As you empty the tank air needs to come inor you are building a vacum in the tank. Be very careful if that happens as those plastic tanks will colapse. With vacuflush you can try leaving the bowl open while pumping out (turn off ghe water first) This will act as a vent

try running the macerator with the pump out fitting open that will also serve as a vent unless you have a y valve to select macerator or pump out

the only issue I ve had withthe sealand is withthe DB reversing. I vebhad ghisnhappen twice. Not sure why although I wonder if a clogged vent wasn't the reason.
 
These might help you get a better idea of how things go together and what the parts look like: http://www.dometicsanitation.com/manuals.asp

The duck bills are located in/on the pump. Right where the hoses hook up to it. You remove the hose from the barbs and unscrew the barbs to get at the duck bills.
 
Neal, the SeaLand pumps don't have the screwdriver slot to get them going, only the Jabsco, Johnson, Sherwood and other macerator pumps with rubber impellers inside have the screwdriver slot. It is at the end of the motor, sometimes with a removeable cover over it. It is the actual back end of the electric motor's shaft.

The purpose of the screwdriver slot is to break loose the impeller if it should "stick" on the inside of the pump housing. When the pump isn't used for extended periods, the impeller has a tendency to adhere to the inside of the pump housing. Then when you turn the pump on, the motor is in a "stall" condition, and you blow the fuse.

With that type of pump, if it hasn't been used for a few weeks or longer, it's a good idea to put a screwdriver in the slot and turn the shaft 1/4 or 1/2 turn before trying to run the pump, to be sure the impeller isn't stuck inside the pump housing.

SeaLand pumps are diaphragm or bellows pumps and don't have the "sticking" problem.
 
Neal,

You can rebuild that filter for about a tenth of the cost of a new one. I have e-mailed you the procedure. I would have posted it here, but it is a Word document and I don't know how to post a word doc to photobucket.

HTH.
 
David

Thanks for the email on the instructions, I have purchased a new filter but saved the old one and your instructions so this winter I can cut it open and practice. Your plan makes a lot of sense.
 
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