Installing a Water Softener - Proper Draining

[Aikouka]

I'm looking to finally install my water softener. I've had it lying around for a while, and my major hold-up has been how to properly drain the unit. I do have an existing water softener in my (rather tall) crawlspace that has been disabled for quite some time; it was bypassed when I got the house, which (arguably) was a bit of a red flag. Anyway, the problem is that it was likely never installed properly as it doesn't have any sort of up-to-code drain solution. It looks like their previous implementation drained to a clean out plug as the drain tube is dangling over top of it.

My current plan -- and what I'm looking to make sure is acceptable -- is that I'd like to move the water softener to be near an existing drain pipe that I can modify to serve as two separate drains. The current pipe comes up vertically from the main sewage line into a sanitary tee. The vertical of the sanitary tee connects to a vent. The horizontal of the sanitary tee connects to a p-trap, which then goes up and into a washing machine box to serve as a washing machine drain. My plan is to replace the existing sanitary tee with a double sanitary tee. The two existing sides would effectively remain the same, and the added horizontal opening would somewhat mirror the washing machine drain except it would terminate at a dual air gap (has two 3/8" connectors).

So, I guess the questions are...

1. Is a double sanitary tee the correct solution? I did a bit of research and it looks like this is the correct choice over something like a double wye. It appears that the difference is in the orientation of the pipes.
2. In regard to codes involving proper p-trap installation, it looks like the only rule in play is that the vertical section shouldn't be more than 24"? Given that the one drain is gravity fed, I need a relatively short vertical piece anyway.

Also, I'll try to add in a photo later that I took of the existing drain setup. This drain setup is fairly recent as it was added in a few years ago, and was done by a professional. Although, in my experience, that doesn't always mean much.

 

[herm0016]

could you use a saddle like this above the p trap on the washer drain? as long as you are above the p you should be fine with an easy solution like this.

Drain Saddle Clamp with Quick-Connect Fitting for 3/8 in. Tubing

 

[Aikouka]

could you use a saddle like this above the p trap on the washer drain? as long as you are above the p you should be fine with an easy solution like this.

Drain Saddle Clamp with Quick-Connect Fitting for 3/8 in. Tubing

Huh... I haven't seen anything like that before. I take it that you just drill a hole to facilitate using the opening? Although, looking into it a bit more, I'm not sure if that will work due to the existing drain line being for a washing machine. I believe washing machine drains are supposed to be 2", and I know the one installed is 2". These devices appear to be designed for kitchens, and as a result, only support up to 1.5". I'm poking around Amazon, so I'll see if there's a variant for 2" piping. It would certainly save a ton of time!

EDIT:

I'm not sure if they make them in a larger size, but I did find a 3D model on Thingiverse. Although, it's 1/4" and also likely for smaller drain pipes. So, I'd have to modify it to work with larger pipes.

 

[Aikouka]

Here’s the drain in question. Unfortunately, replacing it will likely require some cutting and rebuilding, but you do what you gotta do.

 

[Sukhoi]

Can't you just get a PVC saddle tee?

 

[Micrornd]

It looks like their previous implementation drained to a clean out plug as the drain tube is dangling over top of it.

This is the correct way to install it. Drain lines from water softeners are not supposed to be directly connected to sewer drain lines. An air-gap is required by code to prevent contamination in case of sewage backup. Normally this is done by running the softener drain line to the vicinity of a floor drain, laundry tub or an open drain pipe (that has a p-trap in it) and suspending it above it.
All of this should be very clearly stated in the installation instructions of your water softener and examples of how to do it given, as this is a requirement of the NPC (National Plumbing Code).

 

[Aikouka]

This is the correct way to install it. Drain lines from water softeners are not supposed to be directly connected to sewer drain lines. An air-gap is required by code to prevent contamination in case of sewage backup. Normally this is done by running the softener drain line to the vicinity of a floor drain, laundry tub or an open drain pipe (that has a p-trap in it) and suspending it above it.
All of this should be very clearly stated in the installation instructions of your water softener and examples of how to do it given, as this is a requirement of the NPC (National Plumbing Code).

I think there’s a misunderstanding here because I was never suggesting to directly connect it to the waste line. My problem with what appears to be the existing solution is that there’s absolutely no guarantee that the softener’s drain line will actually drain into the waste line because it’s simply dangling over a board mounted between two joists. From what I’ve seen, the drain line should still be mounted to avoid it being knocked off/away from the drain. For example, I've seen these products for sale that are essentially wode plastic funnels with hose clamps built in so you can properly mount something like a water softener's drain to a floor drain.

I did consider using the clean out for the newer water softener install, but two things came to mind...

1. Do I need a vent? That sewer line starts at the kitchen sink comes down, and mostly travels along ground level (at a slope, of course). The clean out is probably a good 6 feet from the point where it starts traveling along the ground. If I recall from the kitchen remodel, the sink is properly vented.
2. Is it even a good idea? One aspect that I never card for in regard to using the clean out is two-fold: (1) It will introduce a bunch of suspended piping off the main waste line, (2) without proper planning, I can end up blocking the clean out port for that waste line. This is part of the reason why I wanted to rework the washing machine's drain as I thought it seemed like the more "proper" setup rather than hacking in a solution.

Can't you just get a PVC saddle tee?

Do they make them in the right size? I took a look, and I could easily find saddle tees for 3" or 4" Schedule 40 DWV PVC, but there didn't seem to be anything for 2". Although, from what I've seen, that's expected as saddle tees are usually reductions. However, there's nothing that says that I cannot use 1.5" PVC for the water softener. So, I could use the 2"x1.5" Saddle Tee like this one.

Although, it looks like they're kind of rare. I don't really have a qualm with reworking the PVC. It's definitely a pain compared to one of these retrofit devices that a few of you have mentioned. The biggest thing is... if I do decide to redo the PVC piping, is my plan of using the double sanitary tee correct?

 

[herm0016]

I think the T will work great, its not like its having to handle a ton of volume. IMHO, its just a matter of if the softener will produce enough water to keep the trap full. though, I live in a very very dry place and its not an issue most places.

 

[Aikouka]

I think the T will work great, its not like its having to handle a ton of volume. IMHO, its just a matter of if the softener will produce enough water to keep the trap full. though, I live in a very very dry place and its not an issue most places.

Hm, that's a good point, and I'll admit that I don't really know how much water is dumped by these systems. I know the one drain is an overflow, which should theoretically see little if no use. I don't really know how much the discharge will use, but I believe the idea is that it will get used more depending on how hard your water is.

In that regard, would it be better to try to work it into the washer's straight pipe? Now, I'm having trouble finding a good saddle tee... or rather, a readily available one. (I did find this one, but whew... they want $15 or more for any decent sort of shipping.) I should be able to just cut out a chunk and add a normal fitting to that downpipe, right? If I do that, would I want a wye instead of a sanitary tee? I figured I could do a wye to a 45 and then put the air gap in there in what should end up being a vertical orientation.

I think the only consideration that comes to mind is whether the potential combined velocity of the washing machine + water softener brings it over the limit of a p-trap?

 

[herm0016]

on 2 inch, and with modern appliences, i would not worry about the p trap. i think the y and air gap before the washers p trap would be fine. leave a few inches between the trap and the y.

 

[Aikouka]

So, I was down in the crawlspace last night working on getting the area level for the water softener, and there was one thing that I was curious about. Essentially, one advantage of the saddle-tee that people suggest is that it's probably one of the least disruptive methods. One thing that I wanted to look at was the piping going from the existing sanitary tee to the original iron waste pipe.

It looks like what they did was removed the iron pipe (there's still a bit coming out of the cinder block foundation), and use a rubber coupler to join the iron pipe to the PVC. The part that stuck out to me is that there's a decent amount of pipe before you reach the sanitary tee. I didn't have my measuring tape with me, but I'd guesstimate around 8-10".

This made me wonder... is there any rule about having two consecutive sanitary tees? I could make a single cut in that initial vertical pipe a bit close to the existing tee, and insert a sanitary tee with some pipe on the bottom to go into the existing rubber coupler. I recall there being something about the p-trap being far enough off the ground though.

One reason why I'm liking this idea is that the overflow line isn't very high up on the unit, and it's only gravity fed. So, I want to avoid setting the air gap too high.

EDIT:
I’ve done a bit of reading, and it looks like my consecutive sanitary tees would effective create a went went, which it sounds like they aren’t allowed outside of bathroom situations?