Lavac Pump Whistles

BellaMcDaniel · #1 (**permalink**) 01-23-2009

Our 42' Tayana has a 2 year old Lavac Henderson pump in head. In high/rough seas the head "whistles". Any suggestions on what to do? We tried using vegetable oil to see if that help (in head) but no luck.

Valiente · #2 (**permalink**) 01-23-2009

Do you mean it whistles when it's dry or wet? From the feed hose or from the pump hose? Is the diverter valve to the holding tank set to the tank or to the "offshore option"? Do you have a syphon break and could it be this or a joker valve "whistling"? Do you drain the bowl and shut off the intake seacock in rough weather?

I haven't had this problem with my Lavac, but as you can see, I had six supplementary questions occur to me as fast as I could type them...including the possibility of a slight break in your vacuum lid gasket with the moving water forming a "bellows" effect.

Pump it dry and see if it keeps up. I tend to pump dry in a seaway anyway. Even if it's clean, I don't want standing water sloshing around underway, nor do I necessarily want the open seacock.

BellaMcDaniel · #3 (**permalink**) 01-24-2009

It happens either in holding or offshore option. It seems to be a backflow issue when it forces air back into the pump it whistles or whines. We don't have an anti syphon value. Thanks for the questions. We'll keep narrowing down the answers/questions.

soulesailor · #4 (**permalink**) 01-24-2009

On my lavac set-up I have an anti-syphon valve on BOTH the water feed line and the outflow line, just after the pump. This way all hoses on both sides of the head will empty completely and no syphon will occur.

It sounds like your outflow hose may be still full and trying to create a syphon but can't get past the pump with any success.

BellaMcDaniel · #5 (**permalink**) 01-25-2009

Thanks. That sounds like it could solve our issue. We will give it a try. Happy Sailing.

Valiente · #6 (**permalink**) 01-25-2009

Quote:

Originally Posted by soulesailor

On my lavac set-up I have an anti-syphon valve on BOTH the water feed line and the outflow line, just after the pump. This way all hoses on both sides of the head will empty completely and no syphon will occur.

It sounds like your outflow hose may be still full and trying to create a syphon but can't get past the pump with any success.

This is to my knowledge the "bulletproof" installation. Just make sure the anti-syphon doesn't contain a spring-loaded piston-style vent, but rather just a barb with a hose you can run above the waterline.

To truly make it a thing of beauty, put a one-way "joker" valve on the vent line so that if you are over on your ear (hopefully with a head pumped dry!) you won't syphon water down the vent line into the toilet.