Sundancer 240 (2000) Vacuflush issues/mysteries

[Ian Pace]

Hi All,

I think this is my first post here and it unfortunately has to be about the head….

I have a 2000 Sandancer 240 which came from factory with a Vacuflush system. I have searched all over the forum and internet but can’t seem to find anyone with my same issue…..

The Vacuflush system does not have an external holding tank and only has an overboard discharge, in the head i only have a key switch with on/off as per below:

I have replaced all 4 duckbill valves, bellows and o ring kit, however I have a VERY strange issue:


With Seacock Open:
Flushes, builds vacume in around 30 seconds and shuts off. Works perfecrtly.



With Seacock Closed:
Sometimes wont have much vaccume and on occasions it does. When It does, pump shuts off after 3-5 mins. Other times it keeps running. If during this process I open the seacock, it will build up the vacume within a few seconds.


It’s totally confusing…. As I expect it to lose vaccume and not build up pressure when the seacock is open and not the other way round!

It seems that it needs some kind of vent for it to build vaccume…. Which is strange as it wasn’t designed that way.


Altough I am not in the US, we still have the 3 mile regulation, so I don’t wish to have the seacock open unless I need to discharge when out at sea….. don’t fancy swimming in our own poop anyway



Anyone ever experienced anything similar?

 

[Lazy Daze]

Actually, that vacuum "issue" sounds right to me. Vacuum builds up between the pump and the head but the displaced volume of air has to go somewhere. In this case, instead of a vented holding tank, it's going into the ocean. But with the seacock closed, it has nowhere to go so things "back up". Your best solution is to probably toss a holding tank in there and then add a pump-out fitting. You could add a transfer pump or a macerator if you still wanted the overboard discharge feature. But if you have access to a pump-out facility, that's obviously the best.

 

[Ian Pace]

i assumed that it can still be used and then discharged when the vacuum tank is full..... unfortunately we have no access to a pump out facility, so my only option is an over board discharge.

Is it possible that this was only designed for the waste to go out straight to the sea everytime you flush?? that i find very strange!

 

[Lazy Daze]

i assumed that it can still be used and then discharge when the vaccume tank is full..... unfortunately we have no access to a pump out facility, so my only option is an over board discharge.

Is it possible that this was only designed for the waste to go our straight to the sea everytime you flush?? that i find very strange!

Yes, you're correct. That's the way it was designed (at least this particular style). It's not the only option out there, of course, but that's how the original owner (or selling dealer) spec'd it out when they ordered it.

You can still do an overboard discharge - just put a holding tank in there. They're not that expensive. A regular macerator would be less expensive than a transfer pump, as well.

Or... convert the head to a regular portapotty - they're about as simple as simple can get.

 

[Ian Pace]

Will just add another item to the shopping list ..... waste tank +carbon filter + mecerator

will this shopping list ever end?

 

[unsalted]

Is it possible that this was only designed for the waste to go out straight to the sea everytime you flush?? that i find very strange!

I wondered that as well but I looked up the spec sheet on your boat and it does have an option:

Direct Overboard VacuFlush® Head (Int’l)

So maybe that’s how it came originally.

 

[Ian Pace]

yes its a standard extra.... still find it silly but anyway hehe.

at least i have space for a black water tank.

 

[Lazy Daze]

Will just add another item to the shopping list ..... waste tank +carbon filter + mecerator

will this shopping list ever end?

It's like the tide - it ebbs and flows but it's always there. It's all about making the boat the way YOU want it.

FYI, there appears to be number of old screw holes in the bilge shelf. Be sure to plug them. If water has already gotten down in there, it can cause issues.

 

[Ian Pace]

Yeah those holes are on my todo list before the season..... one of many hehe