Zone short cycling

[Fort Gates]

I have a 10 year old Hunter irrigation system with four zones. Three of the four zones work fine but zone three short cycles with the pump cutting on and off. Water does come out of the heads but not properly. The system has a two HP motor which draws water directly from a large river. The whole system is on a timer. I dug up the valve and the solenoid seems to be operating properly (it clicks when power is applied) and there are no visible obstructions. The last time this happened it was a different zone and the culprit was a tiny gar skull gumming up the works. Could it be a broken/cracked pipe? I'm to the point of calling a professional to check it out unless someone can give me some guidance.

Thanks,
Rich

 

[WorthFlorida]

As you stated, something got jammed somewhere. When drawing from a river or lake, you be surprised what’s get past the screened inlet. Broken pipes will not cause this. At this time, remove all spry heads on any pop ups you might have. They can get plugged up with sediment, rotten vegetation and anything else. With the heads remove turn on the irrigation to flush the zone. Then check the spray heads.

Is this pump part of your domestic water? Irrigation and domestivc well pumps are different. Just sounds like you have a pressure switch. Irrigation pumps do it need a pressure switch or pressure tank.

 

[Sponsor]

 

[Valveman]

Like Worth said, if you are running this off a timer there should be no pressure tank and pressure switch. If you need to run hoses sometimes, a pressure tank/pressure switch is needed, but then you have to make sure every zone uses enough water to keep the pump from cycling, or use a Cycle Stop Valve to do that for you.

A settling pond with a screened inlet can help keep fish bones and stuff out of your system.

 

[Fort Gates]

Thanks for the replies. The irrigation pump is used exclusively for the sprinkler system and has both a pressure switch and a small bladder tank. The bladder tank appears to be in good shape and was put on at the suggestion of they crew that installed my system. I do have a T with two spigots to hook up a hose if needed. I pulled the heads off the nine spray heads on the zone and cleaned the screens some of which were pretty clogged. The system still cycles off and on. I have also adjusted the pressure switch both up and down without any change.

Plus, now the fourth zone refuses to come on at all. The pump cycles on then cuts off without any of the heads activating. If I open one of the spigots the pump will cycle back on providing plenty of pressurized water out of the spigots but still none out of the sprinkler heads. When I close the spigot the pump shuts off.

I'm still trying to locate two of the heads in zone four since it hasn't been run in quite some time and vegetation has grown over the pop up rotors.

Again, thanks for the suggestions.

 

[WorthFlorida]

Zone four solenoid may be bad. Irrigation controllers can detect a solenoid when it has a short but not an open. Open a spigot to run the pump, at zone four valve, turn the solenoid counter clockwise a 1/4 to a 1/2 turn. Water should flow. If not it may also be clogged up or the diaphragm is too stiff and needs to be replaced.

The cycling zone there still has to be debris somewhere. If you know where the last pop up is in this zone, remove the spray head and run the pump. If it still cycles then work back to the next pop up. But perhaps you need those other two pops that you’re trying to find because of just too much back pressure. This is one reason to use an irrigation pump that doesn’t use a pressure switch. Pressure tank does nothing for irrigation. It might have been recommended because you already had a well pump.

 

[Valveman]

A lot of people still use pressure switches and tanks on irrigation pumps so they can also use yard hydrants.

 

[WorthFlorida]

Hi Cary, I’m sure you know this but it is for the DIYer who may read this and I value your comments highly. I’ve learn a few things from your posts.

I’m sure there are thousands of homes using hydrants connected to their irrigation system but here is the problem. If it’s not a potable water source then it can become a health hazard. There is a garden hose connected to a spigot and you want to water a garden area. You the adult knows not to drink that water but the next homeowner doesn’t know it and on a hot day may want to take a drink of water from this hose. Worse yet the grandchildren want to help grandma water the garden or use the hose to play on a hot day. Very easy for a kid to wanting to take a drink from this hose.

Another is since sprinkler heads are buried in the ground and when the pump is off, contaminates can enter the system through the sprinklers. This is highly covered when taking a course for an irrigation license. The hose is opened, the pump turns on and someone could drink contaminated water. Not very good after the yard was treated with chemicals. I know at every pump there is a spigot for priming and running the pump after maintenance so you alway need to be careful.

Orange County (Orlando), Florida where I live has reclaimed water system for irrigation installed when the neighborhood was built. It is written in code that connecting yard hydrants or spigots to a reclaimed water system is prohibited. Every two years by law the entire system is smoked tested so that no one had tapped into and illegally connected it to the domestic water system. I learned this from the guys doing the test one day and a note from the water company that water may be disruptive for a short time.

 

[Valveman]

I agree never connect a hose to a purple water line.

But many irrigation systems are connected to potable water where hoses are OK or are even the only means of irrigating. Kids will and need to be able to drink from hoses. Lol. So just don't connect hoses to a system without safe water.

Reclaimed water scares me. Estrogen, antibiotics, and other drugs are not being filtered out of waste water. Run off gets into everything, meaning all of us are on the pill, like it or not. I have even heard that some lakes have 90% female fish these days. When 100% of our fresh water is polluted, I guess we will finally realize the earth cannot sustain 7.5 billion parasites.

 

[Fort Gates]

Zone four solenoid may be bad. Irrigation controllers can detect a solenoid when it has a short but not an open. Open a spigot to run the pump, at zone four valve, turn the solenoid counter clockwise a 1/4 to a 1/2 turn. Water should flow. If not it may also be clogged up or the diaphragm is too stiff and needs to be replaced.

The cycling zone there still has to be debris somewhere. If you know where the last pop up is in this zone, remove the spray head and run the pump. If it still cycles then work back to the next pop up. But perhaps you need those other two pops that you’re trying to find because of just too much back pressure. This is one reason to use an irrigation pump that doesn’t use a pressure switch. Pressure tank does nothing for irrigation. It might have been recommended because you already had a well pump.

 

[Fort Gates]

OK, I finally got to mess with my system again the other day after finishing up some other projects. Happy to say everything seems to be working as designed. I ended up increasing the pressure at the pressure switch by two full turns and that solved the zone from cycling off and on. That was after I had pulled and cleaned all nine spray heads.

Now for the zone four problem. I dug up the switch again and checked the solenoid which appeared to be working fine. Since the zone still did not work I started taking apart the valve. I partially loosened one screw then started loosening a second at which point water began to flow out of the valve body, which I expected. But when that happened the pump came on and the zone heads popped up and starting working. I tightened the screws back down and the zone stopped. I started loosening again and the same thing happened so, again, I tightened the screws back down and the zone shut off. I went to my timer (Hunter Pro C) and the dial was in the System Off position with "OFF" showing on the LCD screen. So how did the system work if the timer was off? I switched it to RUN, then back off again and let it sit a minute. I then ran zone four manually and it worked fine. I have since run all four zones and everything seems to be working.

I will be leaving the pressure switch in place but am thinking about removing the small bladder tank on top the pump and plugging the hole. This pump is not hooked to anything other than the irrigation system which draws directly from the river. Does anyone see any problem with that? I really don't know what function the tank provides since when the system is running the pump is constantly running.

Thanks to all those who looked at my posts and for the suggestions.

Richard

 

[WorthFlorida]

The Hunter controller opens the valves only. You probably do not have motor start relay installed (all controllers have this feature) because the pressure switch operates the motor. With any hydrants connected, by opening the spigot will allow the pump to turn on as pressure drops. Do not remove you tank, cycling will likely occur when the system is turned off. Pumps with pressure switches from the factory are jet pumps where as irrigation pumps are centrifugal. A picture of your setup be helpful.

If you haven’t check the voltage at the solenoid you may not be getting voltage to it. A quick test is at the controller swap zone 3 and 4 wire. Then turn on each zone. If zone 4 now works and not zone 3 it’s the controller. Depending on your model you can use zone 5 if it exist on the controller or if it’s a plug in module it can be replaced. The controller can be programmed to skip zones. If zone 4 still does not work it’s the solenoid, a slim chance of an open wire. All operate on 24v ac but will usually operate as low as 16-18v.

You said the solenoid seems to be working fine? How? If you can have someone at the controller to turn on the zone, you may feel or hear a click from the solenoid, then it is usually ok. Sometimes by completely removing the solenoid debris can be flushed causing the problem.
Did you loosen the solenoid a 1/4 turn or so and did water flow. If yes then the valve is good and the solenoid is bad.

 

[Fort Gates]

OK, the picture process was a little convoluted so I hope it came through. And I checked the solenoid the same way you described. I touched and listened while my wife activated the zone. Clicked like it was supposed to.

And I guess I'll leave well enough alone and leave the tank on since it's now working the way it has for the past ten years.

Whereabouts in Orlando are you located? I lived there for about 47 years starting out in Pine Hills (when it was safe) then moved up to Wekiva Hunt Club in 1976. Retired in 2008 and came up to northeast Florida on the St. Johns in the middle of the Ocala National Forest.

Thanks for the help.

Richard

 

[WorthFlorida]

You do have an irrigation pump. If you remove the tank you’ll need to the pressure switch. If it works for you then just leave it.