In article s.com, "EXT" wrote:
I have found little need for a check valve. I live in an area that freezes
in winter. If you install a check valve it will hold water in the pipe
allowing it to freeze and then the pump cannot remove any water.

That's why you put the check valve indoors, and angle the pipe downward so it
will drain. I, too, live in an area that freezes in winter -- and I've
*never* had that problem. Your problem was caused by poor drainage of the
discharge line, not by the check valve.

When I originally installed it without the check valve, I found that the
discharge end would end up submerged in the ditch and would siphon water
back into the sump causing it to cycle on/off every couple of minutes. I had
to break the siphon.

That's why you use a check valve: so you don't siphon the ditch into your sump
pit.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.