[C320-list] Head leaks and cannot empty tank properly

[clburti at gmail.com]

Ken,

I’ll address the last questions first. It has been ages since I disassembled a macerator pump for repair, but believethey are designed to prevent backflow. Look online for a tech drawing of your pump and you can verify this. That said, the through hull valve on the discharge, should never be left open. First for safety reasons, second, in US waters you would be in violation of MSD discharge laws.


We have a cheap Jabsco head. It doesn’t leave water in the bowl after flushing, so I don’t know whether pulling water out when pumping the macerator is a problem or not. It seems logical that it might do so normally as I can not recall any check valve in the discharge side of the head plumbing.


There simply should not be any water leaking back into the boat when pumping water out of the vent. I cannot remember what the vent looks like on Commitment as it has been such a non issue for us that I confess that I have neglected to clean it for some time. So I can’t offer any meaningful suggestion other than to figure out how to get it out of the boat so that you can inspect it properly.


Rereading your original post with this one leaves me a bit confused. Your vent sounds like it is not blocked anymore and even if a bit restricted, should not be affecting operation much. What confuses me is that the vent goes to a separate fitting in the tank than the deck pump out fitting. Pouring water down the deck pump out shouldn’t cause a leak out of the vent unless your tank is full. You state that your tank is being emptied and is full when you return, how are you determining that? To eliminate one possibility, I have to also ask if you are checking to make sure that the through hull valve is actually open  when running the macerator?



Fair Winds
Chris Burti
Commitment
Catalina 320, #867



From: kspir4 at cox.net
Sent: ‎Sunday‎, ‎October‎ ‎13‎, ‎2013 ‎1‎:‎04‎ ‎AM
To: C320-List at Catalina320.com
Cc: clburti at gmail.com

Thanks Chris.  I've spent a bunch of time on this and found a few things wrong but I think the blocked vent is the biggest culprit and the problem I have yet to resolve.  I have removed the vent hose at the top (at the through hole) and put pressurized water into it.  I could hear the water entering the tank (the hose is clear).  I then reconnected the vent hose at the top and disconnected it at the bottom before putting pressurized water to that end.  The water exited the outside at weak but steady stream.  Unfortunately I also saw some water leak through the caulked seal on the inside near the penetration in the hull (NOT at the hose/hose clamp).  This must be where the smell is coming in the cabin.  After that, I hooked up all the hoses and ran the macerator pump.  I went topside and heard faint hissing at the vent and felt a very very weak suction pulling air in.  Also, the water in the bowl still empties as it is sucked out.   I think the problem is that the "hole" or slit in the vent at the penetration is too small to let a sufficient amount of air in when emptying the take and out when filling the tank.  The way to fix this is not apparent since the holding tank vent is not like the freshwater and fuel vents back aft - the ones with a screened opening on the down side of the vent.  The holding tank vent is a black plastic knob like piece with a indented section on the bottom quarter that does not have an visible opening (I have pictures that I can email to anyone curious and or think they can help).  Does anyone know if this is a standard vent and, if so, can the opening be made or opened more?  Is there a way to easily remove the vent? (I have tried to twist if off without success). I am thinking of drilling a hole in the plastic cover to let more air pass but that will be the last resort since I don't know if that will make matters worse or introduce new problems 

Also, I think I may be getting some leak by though the overboard discharge valve into the tank since I found the tank full after sitting  a week after it was emptied.  Has anyone experienced this?  Is there a check valve in the pump that keeps the water from coming in and filling the tank if the valve is left open or the valve leaks by?

thanks
Ken Spiro
Moondancer 
#1089
---- clburti at gmail.com wrote: 
> It is almost a certainty that your vent is blocked...the liquid coming out is being forced out and if the hose clamp is loose or the hose has been forced partially off, liquid will be running down the hose, bulkhead and elsewhere...that liquid is why the aft cabin smells.
> 
> 
> 
> Fair Winds
> Chris Burti
> Commitment
> Catalina 320, #867
> 
> 
> 
> From: kspir4 at cox.net
> Sent: ‎Tuesday‎, ‎September‎ ‎24‎, ‎2013 ‎11‎:‎37‎ ‎AM
> To: c320-list at lists.catalina320.com; C320-List at Catalina320.com
> 
> Hi Folks,
> I recently bought a 2006 320 and have had problems with the head from the start.  Many of the problems seem to contradict each other and I was wondering if anyone could help.  First off, I rebuilt the Tetford hand pump so I feel that is working properly (flushing water comes in and waste goes out of the bowl).  I have been using KO solution to help promote decomposition but I don’t think that will help until the problem is fixed.  The symptoms (I know many of them seem to be contradictory) of the problem are:
> 1. Waste smell under settee and in the aft cabin.  I believe it is coming from a leak behind the head bulkhead.  I think it only leaks when I pressurize the system with the hand pump.  I do occasionally see some liquid coming down along either the pump out line or the vent line to the bilge near the waste tank.
> 2. When I use the macerator, it appears to be able to put a suction on the holding tank since it will usually draw out a little bit of waste.  However, at the end, it will always empty the bowl of any water that was in it.
> 3. I have tried to flush the holding tank by putting water in the topside pump out access but it will accept no more than a half-gallon before the tube is filled up and causing some liquid drip from the air vent.
> 
> I wouldn't think the air vent is blocked since I have some liquid coming out when I fill the pump out tube.  If that is the case, why does the bowl empty when I pull suction with the macerator pump.
> 
> There doesn’t seem to be any real inspection port to look into the holding tank for blockage or channels.  Is the only means to inspect the inside (without remove the tank entirely) to remove the small air vent port and look through that tiny hole? 
> 
> Is there an easy way to access the upper hose connections for the pump out hose and air vent to see where the drip is comming from and correcting it when found?  There appears to be an access panel above the shelf that is above the medicine cabinet but it looks like removing it would involve removing some factory caulking that seals the head.
> 
> Ken