Siphon break question

graham1 · #1 (**permalink**) 10-25-2003

The intake to my electric head is plumbed as follows: from the thru-hull to the siphon break to the pump that takes water into the head. (The siphon break is a rubber "duck bill" type). It seems to me that the suction the pump makes bringing the water over the siphon break will be enough to open the break and suck in air.

When I cover the siphon break with my thumb, it brings in water. When I stop pumping and take my thumb off, I can hear air bleeding in and then I can''t bring in any more water no matter how long I pump.

I don''t think a rubber type siphon break will work on the suction side of a pump and the only solution is to use a solenoid. Am I right?

WHOOSH · #2 (**permalink**) 10-26-2003

Graham, the set-up you''re describing is commonly done...and when the siphon break prevents the pump from working well (after all, it IS breaking the siphon...) then it''s either removed or defeated. You want the siphon break on the INcoming line to be between the pump and the bowl. That way the pump is not affected, yet the pump can''t feed the bowl and overflow.

Obviously, the other siphon break is downstream of the pump. Both breaks should be mounted above the dynamic waterline, meaning as high as you can get them for ease of mind.

A solenoid will make things even MORE complicated. You''ve already done this by virtue of using an electric head; no reason to compound the problem further.

Jack

graham1 · #3 (**permalink**) 11-12-2003

Thanks for the reply, Jack.
While I agree with the comment about an <electric> head, there were other considerations.
Graham