On Fri, 4 Feb 2011 08:35:54 -0800 (PST), Mikepier
wrote:

To simplify things in my furnace room I want to tie in my A/C
condensate drain into the 1 1/2" pvc coming out of my sump, and have
it drain outside. I assume I need some kind of check valve for this?
The A/C pump already has a built in check valve, but should I install
another one? How is this normally done?

In Baltimore Co. Maryland, my pvc pipe just goes down 2 or 3 feet, to
the wall, to the floor, along the wall, and then out to the edge of
the sump. The sump has a plastic lid that is sometimes in place, but
it doesn't fit tight and the water just flows around the edge to the
sump. (I don't think mine is ever dry, because I'm at the bottom of a
hill, but it can go long periods without the pump running.)

Condensate is pure water, no vitamins or minerals except what it might
pick up from running along the evaporator and pipe, but that's not
much if anything.

Condensate pumps are used when there is no handy drain lower than the
evaporator, when one has to go UP to the ceiling and across a doorway,
hall, or open space to the sink. Someone I know has her furnace int
he middle of hte basement, so it has to go up just to get to the sump
pump, unless people want to trip on the tube or pipe going across the
floor.