Head pump running

JPGator

Active Member
Apr 25, 2019
495
Treasure Coast
Boat Info
2008 Sundancer 40
Engines
Cummins QSB 5.9 425HO
Ok folks. ‘07 340

My head pump runs on and off every 10-15 minutes or so for a few seconds. I changed and cleaned the head and replaced all the seals. The head flushes, refills and holds the water but the pump still runs. No leaks anywhere I can discern.
My question is what is my next step. Duck bill valves, pressure sensor, what.

JP
 
JP... Here's my story, the year we bought our boat the PO had just replaced the duckbill valves and the system would cycle once 1-2 hours sometimes more or less. This past winter I shut down the head system and then I poured Norflex Digester 1/2 bottle down both heads. It sat until the 1st May when I recommissioned the boat and we have spent 7 days now on the boat and the heads have not cycled once unless we were flushing it.
https://www.amazon.com/BoatersMate-...66980&s=gateway&sprefix=NORFLE,aps,217&sr=8-1
 
Thanks TBC. Before I dive into poo Ill give it a shot. I doubt the valves have ever been changes but I’m not keen on playing in poo either.
 
I'm assuming the seal you replaced was at the bowl. The duck bill valves, as JimG mentioned, are a good place to start. They get dried out and don't close all the way. There are also a couple of O rings around the pump bellows housing that can leak. There's a Sealand/Dometic O ring kit that has both of them. Eventually, you'll have a spares kit of virtually every Dometic part that is out there for the darn vacuflush system. If you're on the hook somewhere, and the head goes kaput, it gets ugly fast without spares.

FLUSH THE SYSTEM WITH PLENTY OF WATER FIRST.

Oh yeah, have a few sets of rubber gloves, rags, and cleaning spray, maybe disinfectant available. A pan that will slide under the unit when you open those connections for the duck bills is handy. It'll make the bilge clean up easier later, a lesson learned the hard way...
 
Thanks TBC. Before I dive into poo Ill give it a shot. I doubt the valves have ever been changes but I’m not keen on playing in poo either.

I have an 07 310 and duck bill valves have been changed but still having the problem you have with yours. Mine cycles about every 5 -10 mins. Flushed and holds water fine, having it checked out one more time. Will let you know what they find.
 
I have an 07 310 and duck bill valves have been changed but still having the problem you have with yours. Mine cycles about every 5 -10 mins. Flushed and holds water fine, having it checked out one more time. Will let you know what they find.
Thanks LS. Please do.
 
I'm assuming the seal you replaced was at the bowl. The duck bill valves, as JimG mentioned, are a good place to start. They get dried out and don't close all the way. There are also a couple of O rings around the pump bellows housing that can leak. There's a Sealand/Dometic O ring kit that has both of them. Eventually, you'll have a spares kit of virtually every Dometic part that is out there for the darn vacuflush system. If you're on the hook somewhere, and the head goes kaput, it gets ugly fast without spares.

FLUSH THE SYSTEM WITH PLENTY OF WATER FIRST.

Oh yeah, have a few sets of rubber gloves, rags, and cleaning spray, maybe disinfectant available. A pan that will slide under the unit when you open those connections for the duck bills is handy. It'll make the bilge clean up easier later, a lesson learned the hard way...

BP is the kit standard for all vacuflush systems on our boats? I would order the parts just want to order the right ones.
 
I know that some vacuflush have 1.5 inch duck valves, and some have 2 inch. I think the pump o-rings are the same for either style pump. If you have an S-series pump, you have 1.5" duck bills, if you have a J-series vacuum generator, you have 2" duck bills.
Here are a couple of examples of repair kits, they are actually combinations of Sealand/Dometic part numbers into one kit, but you should identify the vacuum pump you have on your boat first:

https://seacoastservices.com/vg4-vacuum-pump-rebuild-kit/
https://www.westmarine.com/buy/sealand--vacuflush-toilet-maintenance-kit--2662724?recordNum=7
 
Does anyone know what size the toilet seat is on an 04 340DA? Ours broke from extensive use while underway. Our boat is about an hour and a half from where we live and I forgot to measure for a replacement.
 
Does anyone know what size the toilet seat is on an 04 340DA? Ours broke from extensive use while underway. Our boat is about an hour and a half from where we live and I forgot to measure for a replacement.

Look at the bottom of the toilet, you should have a placard on it with the model number. You may have to remove the plastic cover at the bottom (a couple of screws).
 

Forum statistics

Threads
112,948
Messages
1,422,821
Members
60,930
Latest member
Ebrown69
Back
Top