"Roger Long" wrote in message
...
Yes, eliminate the check valve. They can easily disable one of the most
important safety devices on your boat as you have discovered. They serve
no useful purpose on a pump that pushes the water out unless your hose to
sump volume ratio is such that the water flooding back down the hose when
the pump stops will reactivate the float switch and send the system into
an endless cycle that runs down the battery. Even in that case, no check
valve sucking up the stuff that floats around in bilges can be relied upon
to stay tight. It will still cycle, just slower. There are also
significant head losses through the check valve the reduce the amount of
water the pump can move.

If you are having cycling problems, the vented loop Bob suggests can
reduce the hose volume if you get the loop close enough to the pump.

I do have a check valve on my diaphram hand pump just because it makes it
easier to get it primed and started. It's the rubber flap valve from
extra parts for the same Guzzler pump bolted together and inserted in the
end of the hose. If it jambs, I can just pull up the hose and stick my
finger in to clear the clog or yank the check valve out.

Check valves have no place in a bilge line other than right at end of the
inlet hose.

As to why the old valve worked and the new one doesn't, welcome to the new
world order of Chinese manufacturing domination. Don't bother returning
it for another just like it.


I was thinking about a loop, but how the heck to I install one? It's a
fairly shallow bilge, and I would have to vent it somewhere... another hole
in the boat?

--
"j" ganz @@
www.sailnow.com