Not sure what the answer will be on this but I'm open. I had black water coming up the tiolet. I would pump it down and then it will come back up. I pumped the system when off shore but it didn't pump all the way out. it resolved the problem short term. I went to the marina pumpout station and put the hose on and nothing was coming out, not even a drop of water. (waste). I can see that there's waste in the tank but nothing was pulling up. OK now what the heck is going on here. Am I missing something ? Any Ideas ????
We had this happen to us on a Grand Banks we owned. We had let it go to long between pumpings and the charcoal filter in the vent line had gotten plugged. I am not sure if that could apply here or not, but replacing the filter solved our problem.
The vent is plugged or the charcoal filter if you have one. When you try to add waste to the tank with the vent plugged the pressure builds up in the tank and forces the waste back out the easiest path. Use a dental pick to remove the screens in the overboard vent. As a test, leave the waste pump-out cap loose when you flush and everything should work properly. With the vent plugged you cannot pump the tank empty either. You may even collapse the tank. Been there, done that. Capt. George
My first question is what year and model Tiara do you own?
Most Holding tank systems have a few components that you need to deal with when emptying the tank. If your vessel has a Y-Valve (I bet it does), then you need to make sure it is in the correct position (either overboard discharge or to the deck pumpout fitting). If the valve is in the wrong position and you try to empty the tank, you can actually invert the one way duck valves and then the system needs to be dissasembled in order to repair the system (not a pleasant job!). The other item is the overboard discharge thru-hull valve needs to be open in order discharge the tank overboard.
1) Overboard Discharge (pumping into the ocean) w/ Y-Vavle - first turn the Y-Valve to (from tank to overboard discharge), then open the overboard thru-hull waste valve. Make sure you are the designated distance from shore and the boat is safely in forward at idle (make sure someone is at the wheel). Turn on the Waste Macerator switch. It should not take more than 3 - 5 minutes to empty the tank. When you are done, shut off the macerator switch, turn the Y-Valve back to (from tank to deck pumpout) and then shut the Overboard Thru-hull (make sure to secure the handle closed with a tie-wrap or cable lock so you are Coast Guard legal). Add waste tank chemicals to each toilet and flush - Done!
2) Station pump out with Y-Valve - first make sure the Y-Vavle is in the correct position (from tank to deck pumpout). Open the deck fitting cap and place the pumpout hose firmly in the fitting and then open the valve. It should take 3 to 5 minutes to empty the tank. I then fill the waste tank with water (do not use a drinking water hose to do this or you can contaminate it!). Then pump the tank empty again. Add waste tank chemicals to each toilet and flush. Done!
If you overflow the tank and it seems you have, you will likely have to replace the charcoal vent filter. Once this filter gets wet with waste it will no longer work and your boat will be in a continuos cloud of stink.
If you did try and pump overboard with the valves in the wrong position and you did invert the duck bill valves, you will have to have them taken apart and repaired. If you do not know exactly what you are doing, I would hire this out. Warning, it is not going to be cheap. This is essentially a hazardous clean up situation that requires special suits and respirators.
Do not try and flush the toilet once the tank is full. If you overpressurize the plastic tank, it is possible to rupture it. If that happens, you will have more of a mess than you can imagine and the repair bills will be extremely high.
Hopefully you just had the valves in the wrong position and you did not do any damage to duck bill valves. Good Luck!
Not sure what the answer will be on this but I'm open. I had black water coming up the tiolet. I would pump it down and then it will come back up. I pumped the system when off shore but it didn't pump all the way out. it resolved the problem short term. I went to the marina pumpout station and put the hose on and nothing was coming out, not even a drop of water. (waste). I can see that there's waste in the tank but nothing was pulling up. OK now what the heck is going on here. Am I missing something ? Any Ideas ????
Lets start simple.
If waste is coming back into the tank, you probably need a new duckbill valve.
Most are pretty easy to change. Pump the tank down first (we'll get to this in a minute), and flush several times to ensure only water is in the line.
You pumped overboard offshore, so your Y-valve was turned towards the macerator. Make sure the valve is turned towards the pump out. There will always be a little left in the bottom of the tank. Once the level dips below the top of the discharge hose you loose your suction. You can get a little more out but not all. You can also try to run water from a hose down the pumpout connection and see if the tank fills.
If the Y-valve is in the correct position, have someone try pumping why you look at the tank. If it is plastic you should be able to see the top suck down with vacuum. If you see this and nothing comes out, check the vent and filter (if applicable) for clogging. You may or may not have a inline filter. I've heard of cases where fluid got into and essentially blocked the filter.
If the vent or filer is clogged I could see the duckbill valve inverting. The system would need to draw air from somewhere and that would be the path of least resistance. I'm not sure how having the Y-valve in the wrong position would do that. On my system the Y-valve would effectively block off the path the the tank and the bowl but there could be other designs that I'm not familiar with.
He mentioned that he tried pumping overboard and at a pumpout station and there is still waste in the tank. That tells me he had the valves in the wrong positions.
I have seen a Y-Valve in the wrong position when trying to overboard discharge invert the duck bill valves.
Scenario - Thu-hull open, Y-Valve in the to deck fitting position, turn on the discharge pump. The pump pressurizes the lines, but the Y-valve is in the wrong possition with the cap on and waste can't go anywhere. When you shut off the pump, the pressure in the lines, forces the waste back towards the tank and inverts the duck bill valves.
The only scenario that I can see where he could not pump out through the deck or overboard is this.
Thru-hull shut, Y-Valve in the (from tank to overboard discharge). This would keep you from pumping overboard and from pumping through the deck fitting at a pumpout station.
A clogged vent line could keep you from being able to pump the tank out, but if the tank is full enough to back waste up in the toilet, some waste should have come out when trying to pump out at least until the vacuum in the tank overcame the pumps ability to suck the waste out.
I couldnt pump out threw deck fitting and found out the y valve was in the overboard pos. turned the y valve to deck and pumped out in minutes. Make sure to lock y valve in deck pos.
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