"David Martel" wrote in message hlink.net...
I agree with Ng that you may have a problem in the rotary valve.
Dismantle it and look for signs of wear on the rotor, and the wear strip.
You probably should replace the big o-ring too.

Dave M.

Thank you for all your responses. Very good troubleshooting tips.

I did solve my problem. I had to dismantle the main rotary valve (the
bulky one being held together by the 6 screws). Inside it .. I noticed
that atleast one of the gasket had mis-located. It was not in place. I
slid it back into place .. put the valve back together.

And then .. i started to feel the "suction" at the bottom of the
venturi valve unit. It took a few hours to empty out the water in my
tank .. but now everything looks great.

Thanks

SRao