Whole house water filter: Concerned about backwash from sewage

[montisqu]

I had a Aquat softener and filtration system put in last week. I believe the connection is as follows:
incomings line -> filter -> softener -> house

I think both the filter and softener has drain lines connected to a sewage/drain pipe.

This week, the filter started flushing water nonstop so the plumber came and shut it off. He will be back later this week to fix it and he will need to contact the company to diagnose because he doesn't know what the issue is.

My question is...can the sewage/drain line backwash into the filter? Aren't there any engineering/plumbing/safeguards to prevent this from happening?

 

[Cacher_Chick]

Softener or filter backwash drain lines should never be hard-plumbed to the drain system. There must be an air gap between the end of the discharge line and the drain system, which here is commonly done by using a standpipe or a laundry tray, much like a clothes washer.

 

[Sponsor]

 

[Bannerman]

Both the filter and the softener need to restore capacity or flush out the media on occasion.

The filter, depending on the type, capacity and water conditions, will likely backwash for approx 15 or 20 minutes, usually every 3 to 7 days. The softener will perform a regeneration cycle for roughly 2 hours, probably weekly. As these proceedures are normally programmed to occur during the night when minimal water is being utilized in the house, you would usually not be aware of when this occurs. The discharge from both units, flows to the drain.

 

[montisqu]

Yes, the manual says the regneration occurs at 2am (the clocks are set correctly).....however, it was flushing nonstop for the entire day. This suddenly happened.

Here is the entire system:
https://drive.google.com/open?id=0By7XFUbeHnu5dzN4RFpsZjZsaHM

Here are the lines going in and out of the system and the interconnections between filter and softener:
https://drive.google.com/open?id=0By7XFUbeHnu5c25lR1NyRDRNbms

Can you check if the lines are correct?


Also, on the first day the system was installed....there was a massive flood on the floor. The plumber had put the filter drain tube "half way" into the PVC drain pipe. So half was going into the drain pipe, the other half was on the floor. I fixed it by putting the drain tube into the PVC drain pipe.

My concern is that drain backwash coming up the PVC pipe and going up the filter drain tubes back into the filter and ruining it. What if the plumber accidently switched the input/output lines?

 

[Reach4]

Yes, the manual says the regneration occurs at 2am (the clocks are set correctly).....however, it was flushing nonstop for the entire day. This suddenly happened.

You want to change that. You don't want them backwashing at the same time.

You are supposed to have a gap where the drain tubes could not suck in anything, even if the standpipe was flooded. Since these are under pressure, sucking is unlikely. Still, you should read up on the subject.

Are these on your lowest floor?

 

[montisqu]

These are in the lowest floor...garage (1 floor house). The person that built the house said something about a gravity fed system (not sure if he was talking about the water or heating system).

So why would the plumber install all the drain tubes from the filter system inside the PVC tube? Should I tell him to leave a "air gap"? Although that
sounds dangerous because if the angle changes if the tube moves slightly....it would flood the garage.

 

[Reach4]

So why would the plumber install all the drain tubes from the filter system inside the PVC tube?

It's easier, and it had been done routinely for years before that became not code.

Adding an air gap is easy as a DIY job . Post a photo of where the tubing goes.

The reason I asked about which floor is if the systems service a lower floor, you want a vacuum breaker.

 

[Bannerman]

I see 3 tubes shoved into the drain riser, with no air gap on any. What is the 3rd drain tube for? The softener and filter each need one. If the 3rd is connected to the overflow fitting on the brine tank, it appears the drain riser is higher than the brine overflow so the brine tank, if it ever overflows, will not drain to the drain riser.

Here's a link to a single appliance air gap fitting.
http://www.homedepot.com/p/Keeney-M...ain-Water-Softener-Air-Gap-PP855-69/204374532

There are also versions for multiple appliances.
http://www.airgap.com/airgapLargeImages/dialysis_5.htm

 

[montisqu]

Yes, the brine tank height is lower than the drain riser. Not 100% sure the 3rd line is from the brine tank overflow, I will check and report back.

Here is what the service manual says:

• If the unit is located where the drain line must be elevated, you may elevate the line up to 6 feet (1.8 m) providing the run does not exceed 15 feet (4.6 m) and water pressure at conditioner is not less than 40 psi (2.3 bar). You may elevate an additional 2 feet (61 cm) for each additional 10 psi (0.69 bar).
• Where the drain line is elevated but empties into a drain below the level of the control valve, form a 7-inch (18-cm) loop at the far end of the line so that the bottom of the loop is level with the drain connection. This will provide an adequate siphon trap.
  
• Where the drain empties into an overhead sewer line, a sink-type trap must be used.
• Important: Never connect drain line into a drain, sewer line or trap. Always allow an air gap between the drain line and the wastewater to prevent the possibility of sewage being back-siphoned into conditioner.

I don't know what the pressure is...but shouldn't standard water pressure in a new house be 40 psi or higher?

 

[Bannerman]

Water pressure is not a concern for your drain configuration as your drain riser is directly behind the units. As a softener or filter are usually installed where the main water line enters the home, in some homes, there is no drain nearby. In those situations, the softener and filter drain tubes maybe run upwards to the basement ceiling, across a distance and down to where a suitable drain is located.

The loop mentioned, is used when the drain line is raised but then drops substantially below the level of the softener/filter. The lower discharge level could result in syphoning, causing a negative pressure situation in the tank during regeneration/backwash.

Depending on a municipality, town water service is often pressurized to 60 psi. Some areas require pressure reducing regulators in each house to reduce the pressure if the municipal feed is over 100 psi. If the water source is your own private well, then your well pump pressure switch would be typically set to either 30 psi on - 50 psi off OR 40 psi on - 60 psi off.

 

[montisqu]

Sorry.......are you saying that the current setup shown in the photos is OKAY? (besides the air gap thing which I will fix)

 

[Bannerman]

Yes, Great! (other than the lack of an air gap and the ? drain line)

 

[Cacher_Chick]

So why would the plumber install all the drain tubes from the filter system inside the PVC tube? Should I tell him to leave a "air gap"? Although that
sounds dangerous because if the angle changes if the tube moves slightly....it would flood the garage.

The discharge hose should be secured to a mounting bracket which holds it in place and allows for the required air gap.

 

[montisqu]

Great, thanks everyone!

On a side note....can someone tell me how this particular air gap works?
http://www.lowes.com/pd_159865-72906-SF1913___?productId=3961589&pl=1&Ntt=air+gap#3d

The tube goes into that "cap" and then the cap is placed inside the standpipe? How is that different from putting the tube directly into the standpipe (like in the photo)?

 

[Reach4]

On a side note....can someone tell me how this particular air gap works?

That is a cap for one of these:

 

[Bannerman]

The Lowes link is to a cap only. That is not the air gap assembly but is a replacement cap incase the original cap is ever damaged.

As your drain utilizes a standpipe, you would be best to obtain an airgap intended for that purpose as opposed to the counter mounted version which Reach included a photo of.

 

[ditttohead]

UPC states that an air gap must be installed no less than 1" or 2x the diameter of the pipe, whichever is greater.

 

[Mikey]

Check with your local building official to see what your local code requires to be sure, since not all jurisdictions follow UPC. There are air gaps specifically made for water softeners:

 

[Cacher_Chick]

Securing the hose to any functional mounting so that the end is secured 1-2" above the opening of the standpipe fulfills the requirement without having to purchase any specifically designed air gap fitting.

 

[Bannerman]

@ cacher_chick:

While what you stated is true, as the discharge is under water system pressure, the risk of splattering is high. As the closet is enclosed by drywall and is located on the main floor and I expect a floor drain is not close by, the damage realized through misdirected water would most likely cause major damage. The price of an appropriate air-gap fitting would be a cheap method to ensure the drain water, all flows to where it is intended.