Need to stop sprinkler system from siphoning from water treatment

Users who are viewing this thread

sp00kster

New Member
Messages
15
Reaction score
0
Points
0
Seems the more I attempt to fix - the more unanswered questions arrise.

I removed the dual check valve to have tested / replaced - the house water would not quit draining out - noticed after long period of time that water was getting warm, then hot. I had to finaly had to go close the shut off valve at the hot water tank upstairs some 30' + away. This does not seem right.

I have described to the local plumbing supply house of my plight and they were as supprised / disbelief as the most of you all were / are. They talked well over my head with many ideas then sold me some sort of inexpensive flow meter / gauge to be installed right where potable water enters house past all water treatment. They explained to me in laymans terms to my best understanding that I needed to find out first if it was truely drawing off of the house water and not simply de-pressureizing (sp) the water conditioner tanks (ie.. carbon, green sand and softner tanks). As well I should lower both pressure switch settings to more truely match the well pump capacity.

I am about to throw my hands up - I now know more than I ever wanted to know about plumbing and at the same time know less than when I started. I think it is perhaps time to get out check book and start getting estimates to find out what is going on here.

Thanks everyone!!
 

Marc

New Member
Messages
21
Reaction score
0
Points
0
I noticed one other thing... I thought chlorinating water before a softener was a bad idea? Perhaps I'm just mixing the order up in my head.
 

sp00kster

New Member
Messages
15
Reaction score
0
Points
0
Nope - chlorinate first then syn. carbon to remove chlorine then softner
 

rickford66

New Member
Messages
18
Reaction score
0
Points
0
Location
Michigan
Just wanted to chime in with an uneducated question. I've been reading some of these posts trying to learn something. I've also looked at the diagram here and I wonder if the retention tank is similar to the pressure tank. Does it also have an air bladder in it? If so, it would explain the slow bleed of pressure... but like others have said, the check valve must be leaking.
 

Gary Slusser

That's all folks!
Messages
6,921
Reaction score
22
Points
38
Location
Wherever I park the motorhome.
Website
www.qualitywaterassociates.com
A retention tank with captive air wouldn't cause the problem as long as the check valve was sealed closed B U T...

I wonder if the water treatment is backwashing and regenerating while the irrigation is running; especially the largest zone.

If so, the irrigation should be changed so it is not running at the same time; at least the largest zone.

Assuming both are running at the same time, then the check valve must open to feed the water treatment/house so it can backwash and regenerate. That will/can/could allow chlorine backflow back through the check valve. And a substantial amount IF the flow to the large zone is equal to or greater than the DLFC gpm of whatever piece of water treatment is in backwash. A softener will have the lowest gpm (drain line flow control) as little as 1.5 but as much as 3 gpm, but the carbon filter can be as much as say 5-10 gpm. The greensand filter is redundant and should not be needed with a chlorination system.... but will flow at maybe 5-10 gpm also.

AND the pressure tank is supplying both water uses, irrigation and water treatment, while the pump is NOT running. Meaning that the backflow will be higher when the large zone is running with say the the softener is in backwash. So most flow from the pressure tank, and then the pump, will be to the large zone as opposed to the softener. And when the softener is in slow rinse/brine draw (for up to an hour plus), the flow is .25 gpm (read point 25) and the check has to open to supply it.... and stays open, so in effect there is no check valve when this happens!!!

So the question is, does back flow happen every time the irrigation is on or only sometimes; which would be when the softener is regenerating? Which can be from every night to every 2 or 3rd night and I could see the irrigation running on about the same schedule....

A leaking toilet or RO or ice maker would also cause a small flow and the pressure tank or pump to feed it through the check valve.

I haven't spent a lot of time on coming up with this theory, but it seems logical and very probable especially IF there is no other explanation as to how chlorinated water gets backward through a check valve; regardless if it is a double or X stage check.

So change the time of irrigation and see the outcome. Or timer the power to the pressure switch controlling the solution feeder so it can't run while the large zone is running.

Another fix may be to tap off the irrigation ahead of the pressure tank and control the pump with a pressure switch on the irrigation line. I'm not sure of this though, and would have to think it through more than I have now.

Just change the time these things operate and I think that will solve the problem.

This problem will have nothing to do with the pump, its capacity or the pressure tank or the pressure you operate the system at etc..

Ah yes... The more I think on this, the more I see the check valve open feeding the water treatment while the irrigation is on...

That's until I think of testing the irrigation water and finding chlorine and none of the water treatment is in backwash or regeneration.... ummmm

Well, at least you know you don't need the greensand filter. :)
 

rickford66

New Member
Messages
18
Reaction score
0
Points
0
Location
Michigan
How can the check valve be open and still allow water to flow backwards through it? What I mean is, water will only flow from higher pressure to lower pressure. If the higher pressure is on the treatment side and the lower pressure is on the irrigation side, then how can the valve be open? I'm a newbie, but I think a spring check valve requires a small amount of forward pressure differential before it will even begin to open. The resting spring pressure has to be overcome to unseat the ball. Going out on a limb, I think the valve either has to be leaking, or there is another path. Is there a service bypass that might have been installed incorrectly that doesn't appear on the diagram?
 

Gary Slusser

That's all folks!
Messages
6,921
Reaction score
22
Points
38
Location
Wherever I park the motorhome.
Website
www.qualitywaterassociates.com
Yes I've thought about another source (like a cross connection) feeding the larger zone too but... this problem goes away and there is no change in the flow of the large zone when he shuts off the water to the house AFTER the water treatment.

For water to get to the water treatment equipment, whether the pump is running or not, the check valve has to open.

During the brining cycle of both the greensand filter and the softener, which lasts up to 60+ minutes normally, the flow is usually at .25 gpm. During backwash. All 3 pieces of equipment will be flowing for at least 6-18 minutes at up to 10 gpm. During final rinses, they will be flowing at up to the same 10 gpm for 4-8 minutes. A backwashed only filter will usually be done in 20-30 minutes. A softener will take an hour and 15 minutes to an hour and 30 minutes.

When the check valve opens, and yes most check valves have a cracking pressure of up to 5 psi, the chlorinated water can mix with and flow backwards due to the flow to the irrigation. Especially with a single check check valve... they invented the double check to prevent that BUT... again, both checks have to be open or the water treatment equipment can not get any water.

I can't recall what the term for this is but it is used in backflow prevention courses. I've seen colored water demos of the problem. You'd be surprised, I was amazed, by what water currents exist inside pressurized water pipes when valves are opened and closed on main lines and branches of the same system. The display used clear PVC pipes with clear and colored water and backflow currents would flow backwards against the flow direction for quite a distance.

Here we have two simultaneous flows in opposite directions with varying pressure and pressure fluctuations in and between both sides of the check valve. Both sides actually go to open discharge, or at least the house side does, with very low flow and pressure individually, and then the pump comes on. Thereby there should be a lot of currents formed at/before/in/after the check valve as it opens and closes.
 

rickford66

New Member
Messages
18
Reaction score
0
Points
0
Location
Michigan
Kind of like a riptide, eh? If you've seen it, then I believe it, but I sure can't see how. :O)
 

sp00kster

New Member
Messages
15
Reaction score
0
Points
0
Well have installed a pressure vacume breaker in place of the double check valve and seems to be doing good. For the posts about the softner system regenerating during the irrigatiing (causing the back siphoning) - all regenerating is timed during late night. I am now going to attempt the last part of this problem but not exactly what area to post this question.

Now that siphoning appears to be stopped. I need to figure out how to shut off the chlorinator when sprinklers come on as not waste chemicals as well as excessive wear on injector. Chlorinator is 220vac liquid injector model that is wired directly into the well pump switch. So it runs whenever the pump runs - regardless house or irrigation. My thought was an attemp to reverse the normal use of a PSR (pump start relay) wired to the sprinkler controller. So instead of using the pump start relay sending a start signal to the 220vac well pump but rather a stop signal to the 220vac chlorinator. My problem is that standard PSR's are normally open I need to either find one that can be modified to be normally closed or possibly used in conjuntion with a DTDP (double throw double pole) relay as to reverse the normal usage.

As I said before any ideas on what might be the best forum for posting this please advise as well feel free to chirp in with any ideas.. As you can tell I am not a plumber and/or an electrician just too damb poor and try to do as much as I can myself.

Again a big thanks to all!!
 

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,771
Reaction score
1,191
Points
113
Location
New England
If you can find a normally closed relay, put it in series with the power to the chlorinator. When the irrigation system is running, have it also open the new relay to the chlorinator.
 

Gary Slusser

That's all folks!
Messages
6,921
Reaction score
22
Points
38
Location
Wherever I park the motorhome.
Website
www.qualitywaterassociates.com
sp00kster said:
Well have installed a pressure vacume breaker in place of the double check valve and seems to be doing good. For the posts about the softner system regenerating during the irrigatiing (causing the back siphoning) - all regenerating is timed during late night. I am now going to attempt the last part of this problem but not exactly what area to post this question.

Now that siphoning appears to be stopped.

I may be misunderstanding, but if the two systems weren't using water at the same time... there shouldn't have been a back syphoning problem; but finding chlorine in the irrigation water said there was a problem. Are you sure the solution feeder is working now?

Now that there is no problem, why do anything, especially something electrical?

I don't know of a better place to continue this than here in the same thread.
 

sp00kster

New Member
Messages
15
Reaction score
0
Points
0
Even though the back-siphoning appears to be stopped. I would like to remove the secondary pressure switch and wire the chlorinator back directly into the well pressure switch. But I cannot without it constantly running when the sprinkler system is on making a very very strong consentration (sp) in the retention tank approx 100 fold stronger than it should be - much wasted chemical, excessive wear on injector, etc....

Seems it would be much better just to have it electrically shut down whenever sprinklers come on.
 
Last edited:

Bob NH

In the Trades
Messages
3,310
Reaction score
9
Points
0
Location
New Hampshire
This seems to be reduced to the same question with slightly different words that you asked in the Irrigation forum with the Normally closed PSR? thread.

Does that answer about how to hook up a DPDT relay solve the problem?

I don't know what controls your sprinkler system because you haven't described that. But turning off the chlorinator depends on getting an electrical signal of some kind when the sprinkler is running.

If the sprinkler is running on a timer that drives multiple independent valve curcuits, and therefore doesn't give you a single signal when it comes on, then getting an electrical signal to shut off the chlorinator may be a little more complicated, but that is what you need to do.

Describe the irrigation system a bit more. If you can't get one signal when the irrigation systems comes on, how many independent valve circuits do you have?
 

sp00kster

New Member
Messages
15
Reaction score
0
Points
0
Yes same question in other forum - Another member posted that a flow switch would be a good alternative and I think that I will do some research on that lead.

Thank everyone for all your help - this is a super forum!!
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks