I have recently installed a whole house water filter, water softener, chlorinator and sediment filter. This was all easy plumbing with 1" PVC. My problem is that the filter has a Fleck valve with a 1/2" ID flexible plastic pipe that is used to recycle the filter. It backwashes overnight a few nights a week to recycle the filter. My problem is how to correctly install this line to my house drain line with the proper air venting that needs to be done. My main drain line is roughly 3" PVC (haven't actually read the measurement off the pipe). Currently I'm just running this drain line outside the house, but I'd really like to run it into the drain line and to my septic system so that all this water that is being pumped onto the ground doesn't become a huge mud puddle. Thanks!

Do not connect it to the sewer, you may get a cross connection. If you must, use an indirect connection with an air gap and a trap in the tubing.

Quote:

---

Originally Posted by doug238

do not connect it to the sewer, you may get a cross connection. if you must, use an indirect connection with an air gap and a trap in the tubing.

---

Yes, basically he would install a 3x2 combo aimed upright on a horizontal portion of the existing drain, then install a 2x1-1/2x2 Sanitary Tee into the top of the combo.

A 2" P-trap would be installed into the side of the tee, and an AAV would be installed into the top of the tee.

I would also recommend a 3x2 reducing coupling be installed into the riser of the 2" trap to make a funnel drain, and then hold the drain hose of the filter/softener a minimum of an 1-1/2" above the top of the funnel drain to prevent sewage from entering the filter/softener drain should the sewer line ever back up.