I have a 2018 270 SDX. I am confused...

[satterjm]

I have a 2018 270 SDX. I am confused about the vacu-flush system. With the water pump on, the toilet flushed at first for a few times, but then started backing up. There’s a key in the head compartment that I thought was only for overboard discharge. If you turn the key once to the right, it’s labeled “head” and a display shows the tank as empty and a motor kicks on. Is this the vacuum motor or a discharge motor? I was able to flush with the motor running. I’m just afraid to accidentally discharge sewage. Also, is the sink water supposed to go directly overboard?

Thanks,

Jason

[wingless]

Welcome to the forum.

According to the Owner's Manual for this boat, PDF page 31, there are three waste configurations: Vacuflush w/o macerator; w/ macerator and direct overboard discharge, no holding tank.

https://bbg1.my.salesforce.com/sfc/p/#E0000000Z21E/a/440000000bS9/majwdSaPWR6PzNNmSXSPEngD5uE456WR7yKtoLvWnB0

The no holding tank option / direct overboard discharge has lots of usage restrictions and is hopefully not the configuration on the boat.

If the boat has the optional macerator, then manually close the overboard discharge seacock and secure it in the closed position (to comply w/ requirements). A wire tie, padlock, or handle removal all meet the requirements for securing in the closed position.

There should be a removable floor panel that will permit viewing what system is installed.

Yes, the sink will discharge the "gray water" directly overboard.

[satterjm]

This is the switch I’m talking about. It I turn it to on, the empty light comes on and I hear a swishing pump sound. With the battery off, I tried to turn the key more. The next position for discharge is spring-loaded. So do you think it’s normal to have to have the key turned to on to be able to flush the head?

[wingless]

Thanks for the image.

Yes, there must be switches and overload current circuit protection for both the head vacuum pump and for the overboard discharge pump.

On my boat those are just additional breaker switches in the rows of dozens of other switches.

On your boat they instead have an ignition key switch style. My guess is that approach was selected because of the head options available on that boat, they just install a different switch plate assembly, appropriate for the configuration.

Yes, when the switch is turned on the system must build / develop vacuum. The motor should automatically turn off once sufficient vacuum is detected.

Ideally it should remain off until the head is used. It is possible that small vacuum leaks exist, causing infrequent cycling of that motor. Frequent cycling indicates excessive vacuum leaks that should be located and corrected.

[satterjm]

Thank you so much! I’ve really been stressed about this. Next time I take the boat out, I will test the auto shut off of the vac motor.

One more question. Should I leave the key switch in “on” all the time then?

[wingless]

If the system is working perfectly, with zero vacuum leaks, then leaving the switch on is fine.

If the system has minor vacuum leaks, then the infrequent motor cycling may become annoying, but other than consuming some electrical current not a problem for the boat.

The switch setting may be decided by the owner.

[satterjm]

You have made me so happy. Thank you so much!!!