Tag Archives: winterization

Sprinkler System Design: Automation, Costs, Contractors, more…

Almost Finished!


Well, if you are working through the Sprinkler Design Tutorial, you’re now pretty much finished with your irrigation design. Here are a few reminders and additional items to consider.

Automatic controllers: For automatic irrigation systems you will need a controller (often called a “timer”) with one “station” for each valve. If you have both lawn and shrub areas you should make sure the controller has 2 or more “programs”. Multiple programs are somewhat like having several “timers” in the same controller. This allows you the flexibility to run the lawn and shrub irrigation on different days. Study the different models and features available on various controllers. Some irrigation controllers and timers allow you to add more zones using irrigation system expansion modules. They range from simple timers to extremely complex computerized units that can monitor all the functions of your entire home!  I suggest you take a look at the article on Smart Controllers if you are interested in the latest innovation for saving you time and water.

Isolation valves: It’s a good idea to install a manual shut-off valve at the point where your irrigation system connects to the water supply. I know I already covered this, but not doing it is a big regret that I hear often.  An isolation valve allows you to shut down the irrigation for control valve repairs without shutting off the water to your house.  You will have to repair a control valve at some time.  I recommend using a “ball valve” for the isolation valve, as ball valves are the most reliable and reasonably priced shut-off valves.   Most inexpensive “Gate valves” will leak.

Wires for valves: For wires going to the automatic valves use wire made specially to be buried. Most people use a special direct burial cable made for irrigation systems. The cable contains 3, or more, separate, 18 gauge wires. On commercial systems, the standard wire used is “#14-1 AWG-UF” which is a single strand, direct burial type wire. One white color “common” wire goes from the controller to every valve, and one individual “lead” wire of a color other than white goes to each valve from the controller. Be sure to read the Irrigation Installation Tutorial.  Also, there is a sketch of typical irrigation system wiring that should help you understand the wiring.

Details: To further help you there is a collection of installation details. These simple sketches will help you figure out how to assemble your irrigation system. These installation detail drawings are normally included as a part of the design drawings for an irrigation system.

Filters: I recommend you install a screen-type water filter upstream of the valves.  Drip systems should always have a filter! This helps reduce maintenance problems caused by small bits of sand which are found in almost all water systems. These small sand grains can make the automatic valves malfunction and also clog sprinkler heads over time.  A $50.00 filter may seem expensive, but it is a lot cheaper than a $100 valve repair job or replacing a dead lawn.  I recommend a “150 mesh screen” in the filter. The filter can be installed underground in a box if you don’t want it visually cluttering up your landscape. On the other hand, it is nice to have it in a more convenient above-ground location for maintenance. Remember, you need to clean the filter screens at least once a year if not more often! For tons of more information on filtration see the Irrigation Water Filtration Tutorial.

Cold Winter Precautions:  Unless your irrigation system is in an area where it never freezes you should insulate the backflow preventer and any other above-ground equipment. Backflow preventers are very expensive, you don’t want an unexpected freeze to catch you off-guard. A few years back that happened here in California and thousands of backflow preventers had to be replaced because the water froze in them and they split open! I usually use foam insulation tape to wrap the backflow preventers and above-ground valves, then wrap the insulation with a layer or two of 10mil black plastic tape to protect it. There are also some pretty neat backflow preventer blankets (essentially a big insulated bag), that are made to fit over the backflow preventer like a big coat. They work well, I use them. (I have a small one in my truck that I use to keep cans of soda cool when I’m on the road. It also makes a great pillow!) If the backflow preventer has air vents or a water blow-off outlet it is extremely important that they not be blocked by insulation! There should be instructions that come with your backflow preventer.

Winterization:  In areas where freezing weather occurs you need to take precautions to protect your irrigation system from freezing. There is a whole tutorial on winterizing your sprinkler system in areas where it really freezes hard. It covers the various methods used, the advantages and disadvantages of each, and what you will need to install as part of your new sprinkler system for each method.

Pumps: Thinking you might need an alternative water source for your sprinklers such as from a pond or lake? Check out the Irrigation Pumping Systems Tutorial.

How much will it cost?

That’s hard to say. I priced out the materials for the little sample irrigation system at the top of this page at $375.00. That included reasonably good quality sprinkler heads, “funny pipe” type risers, Cl 200 PVC pipe, anti-siphon valves, and a very inexpensive $50.00 controller. That comes to about $0.25 per square foot of irrigated area. You may need to add extra for a better backflow preventer and better controller. I would suggest in most cases that you estimate at $0.25 per square foot plus the controller and backflow preventer cost.

Professional Installers:

Irrigation system installation labor generally costs about 1.5 times the cost of the materials. So a sprinkler system needing $1000 of materials will require around $1500 of labor to install. That would be a total cost of about $2500 including materials and labor if it is professionally installed. Installation costs can vary wildly, be sure to get 3 bids.  If any bid is significantly lower than the others it should be regarded as extremely suspicious and it would be wise to use extreme caution before hiring that cheap contractor.  Never pay a deposit upfront unless you are willing to risk losing that money.  If the contractor needs upfront money insist that he/she deliver materials equal to the deposit value to your house prior to payment.  Remember if the contractor needs money upfront to buy supplies that mean the suppliers won’t sell to him on credit.  Irrigation suppliers sell to almost everyone on 30-day interest-free credit, so if they don’t trust him/her to pay them that should be a huge warning to you!  The irrigation installation business is very easy and cheap to get started in. As a result, it has a huge number of contractors that are under-financed, who don’t have the money to buy the materials needed to do the work they get and then fail.  Understand that property laws in the USA allow the supplier who provided the materials to the contractor to place a lien on your home for the value of any materials the contractor buys for your sprinkler system but does not pay for.  It does not matter if you paid the contractor already for those materials.  The supplier can still make you pay for them again.  Fair or not, that is the law.  Be smart, protect yourself!!!


Now you’ll probably want to move on to the Sprinkler System Installation Tutorial.  It covers in more detail the various irrigation parts you will use, like sprinkler risers. It also teaches you to “talk sprinklers” (so you can sound like you know more than you do!), helps you make a list of the materials you will need to buy, provides some helpful forms you can print out, explains which tools can make your day or break your back, and a few other tips and tricks! Be sure you read it before you buy anything or start digging!!! (Just when you thought you were finished!)

End of Tutorial


Tutorial Credits:
(As you will note, I’ve enlisted some assistance from my family members!)

Written by Jess Stryker, Landscape Architect, unless noted otherwise

Constructive Criticism:

  • Julie Stryker, the love of my life!
  • Nathan Stryker, my son.
  • Dan Fahndrich of Farwest Gardens, Inc.
  • The many tutorial users who have asked questions and pointed out unclear topics.
  • And even a few jerks who have kept me (sorta) humble!!!

HTML Coding and page design:

  • Jess Stryker & Nathan Stryker
  • WordPress
  • NoteTab Pro by Eric G.V. Fookes, www.notetab.com


  • Jess Stryker
  • Nathan Stryker
  • Steve Brinkman

Other individual credits are listed on the pages of the tutorial.


This article is part of the Sprinkler Irrigation Design Tutorial
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All Valves Come on and Stay On Continuously

Q.  I just restarted my sprinkler system after it had been winterized. When I turned on the water to the system, all the valves stations came on at once, as if by-passing the timer unit.  Even when I turn the timer unit Off, the sprinklers keep running.

A.   This is a common problem when restarting after your sprinkler system has been winterized, or after the system has been turned off for an extended period of time.  It also often occurs with brand new solenoid valves that have just been installed.  There are a  couple of possible problems that can cause this, so we’ll look at a couple of solutions.  One of the tricks below should get your irrigation valves opening and closing properly again.

Air Trapped in the Valve:

The valves may have air trapped in them.   A small bubble of air becomes trapped in the tiny water ports of the valve, this stops the water from flowing through the port.  Since the water flowing through the port is what holds the valve diaphragm closed, the valve stays open.

1. Turn on the main water supply.

2. Now go to the individual valves and using the manual open & close control on the valve.  The manual open & close control is either a lever on the valve (most often it is under the valve’s solenoid), or it may be a screw on the top of the valve bonnet.  If it is a screw don’t fully remove it, just open it until water starts squirting out.  Set it to open, wait a few seconds, then set back to closed.  If the valve doesn’t close within a minute, try it again.  It may take several tries to get the air bubble to “burp” itself out.  Try tapping the valve to dislodge the air while the valve is open if needed.  Note: old plastic valves may become brittle and crack when tapped, so if the valve is plastic and old don’t tap on it except as a last resort if the air doesn’t come out.

3. If that doesn’t fix the problem, you can almost always force the air out using the manual flow control on the valves.  Unfortunately, some inexpensive valves do not have a flow control.  The flow control is a handle, similar to what a manual valve has, that is on the top of the valve.  It works just like a regular faucet, turn clockwise to close.  Most flow controls have a hand operated flow control, others have a cross handle that is turned using a tool (pliers will work if you don’t have the special valve opening tool.)  A few valves have a screw for the flow control that requires a screwdriver to turn.  Try completely closing and then reopening the manual flow control on each valve.  That should force the air out and fix the problem.

Valve Needs to be Throttled:

If air in the valve doesn’t seem to be the problem it is possible that your valves don’t have enough pressure differential and they need to be throttled in order for them to close by themselves.

Here’s how to throttle them using the flow control adjustment:

Note: some inexpensive valves do not have a flow control adjustment feature on them.  If that is the case you are not going to be able to do this.  You will need to replace the valve with a better quality valve that has a flow control.

1. Use the manual flow control on each valve to close all of the valves.  Now the main water supply should be on, but none of the valves should be allowing water through.  So no sprinklers are running.
2. Start with just one valve at a time.  Rotate the manual on/off lever to the on position.  Open the manual flow control knob all the way (turn as far as it will go counterclockwise). The valve should come on and sprinklers run.
3.  Next rotate the manual on/off lever under the solenoid to the closed position.  The valve should close (it may take it a minute or two to close) but probably won’t, because that is the problem, they won’t close!   If the sprinklers turn off the valve is working correctly, go to the next valve and start again with step #2.  If the valve does not close by itself, you need to throttle the valve.  Continue to step #4.
4. To throttle the valve you partially close the flow control knob.  Start by turning it one full turn clockwise.  Wait a minute for the valve to close.  If it doesn’t close, turn the handle another half turn clockwise.  Wait again.  If the valve still doesn’t close turn it another half turn.  Keep doing this, at some point the valve should suddenly make a whooshing noise and close.  If the valve is broken it will never close by itself and eventually as you close the flow control more and more the sprinkler radius will start becoming noticeably reduced.  If that happens you need to repair or replace the valve.  But in most cases the valve will close by itself after you have partially closed the flow control.  It might take 4-5 complete turns before this happens.

You shouldn’t see any significant change in the sprinkler performance with the valve flow control in the partially closed position, except that the sprinklers may mist a little less (which is a good thing.)  This is called “throttling the valve” and some valves won’t close by themselves unless they are throttled.  The way a solenoid valve works is that the pressure differential as the water goes through the valve is what the valve uses to power itself into the closed position.  If there isn’t enough pressure differential the valve will not close by itself.   Often there is not enough pressure differential when there aren’t very many sprinklers on the valve circuit. When you throttle the flow control you are simply increasing the pressure diferential.

You can leave the flow control in a partially closed position permanently, it will not hurt the valve.  The valve is designed to allow you to do this.  The sprinklers should still operate well as the amount of water throttled when you partially close the valve is not significant.

For valve repair instructions see  how to fix a solenoid irrigation valve.

Winterization for Areas with Periodic Freezing

Q.  We typically have hot summers (month long +100 degree weather,) but recently we are also experiencing very cold winters (recently had 0 degree with -17 degree wind chills that froze a lot of pipes in the city.)  Do you have any suggestions that would be useful about winterization for  Southwest USA irrigation, or any particular materials that are specific to this area I should ask for?

A.  This is a situation which occurs all through the southern US, as far inland as Nevada (Reno sees this type of temperature extremes every year), and up the west coast all the way into the Pacific Northwest.   In these areas you see overnight freezing, which is typically followed by above freezing daytime temps.  To make it worse, it is often necessary in these areas to irrigate during the winter months due to drying wind and high daytime temperatures!  In these places we generally don’t winterize irrigation systems by draining the pipes in the winter, as the soil insulates them enough to prevent freezing.  Sometimes we bury pipes much deeper in these places, say 18″, to keep them below the frost level.   Any above ground equipment will need insulation installed on it to prevent freezing during the nights.  So generally I wrap the above ground pipes with foam or fiberglass insulation, extending down underground to below the typical freezing depth.  Where exposed to sunlight I wrap the insulation with a high grade pipe wrap tape that is UV resistant, or with metallic tape.  Without protection foam insulation degrades pretty fast from sunlight exposure.  Do not use standard duct tape, it is not UV resistant and will be a mess within a year or two.  For above ground valves and backflow preventers you can purchase insulating covers that can be placed over them like a big bag, (one brand name that comes to mind is Polar Parka) or you can wrap them in fiberglass pipe insulation wrap.  Just make sure water can drain out of the bottom someplace, in case there is a leak.  Fiberglass insulation must be wrapped with plastic tape or something else waterproof to keep it dry, it will not insulate if it becomes wet. You can also put thermostat controlled electric pipe heaters on the pipes as another option.

The killer problem is when you have hard freezes that last for several days.  Insulation doesn’t work very well during long duration freezes, as the cold has time to penetrate the insulation.   In areas where freezing weather lasts longer than over-night, but you still need to keep the irrigation system operational, it is a good idea to install electric pipe heaters on backflow preventers and above-ground valves.  If you don’t need to irrigate during the winter in hard freeze areas, then you should do a full winterization process that includes draining water from the pipes.  For more details on winterization see the Irrigation System Winterization Tutorial.