Losing water when filter is running

[sztaylor]

I am losing approximately one inch of water per 5 hours of running pump/filter time. After researching, I learned that the spider gasket on the Pac-Fab multiport valve I have should be changed. Did that (did not glue down - a controversial subject). The water continues to drain out. Replaced the entire key assembly- still draining at the same rate. The equipment is approximately 12 years old. Any other ideas?

[BigDave]

Can you see that the water's going to the waste line on the multi port? Perhaps it's a leak in the piping between the valve and the returns.

[sztaylor]

Thanks for your reply...I cannot see the water moving from the multiport valve connection to waste, but can feel it moving through there. Also, the waste empties into a line connected to the sewer, and I can hear it emptying into the sewer there (and could probably see it if I crawled into the bushes).

[PoolDoc]

Verify that water is leaving via the filter waste. You can do this by drilling a 1/4" hole in the underside of the waste pipe -- and you can patch it later with a piece of rubber from a Fernco coupling and hose clamp, or by cutting and coupling there.

If it *IS* leaking significantly there, then is it IS a multiport valve leak. The question would be: why is a new multiport valve leaking?