Winterizing a lawn irrigation system?

[Simple Sam]

So I just bought a home that comes with an irrigation system for the yard. I live in an area where it doesn't freeze during the winter so I am not familiar with prepping for freezing conditions. The new home is in Reno NV which gets below freezing on a regular basis. The home will be mostly vacant this winter although we will use it on occasional weekends.

The attached photos show the water supply, the sprinkler valves, and another valve that I'm not sure the purpose of. The last valve is in the white pipe with the black cap and is at least one foot below grade. My biggest concern is that the above ground pipes are made from PVC. Are they going to burst the first time the temp gets below freezing? I have shut off the two valves that are above ground but I am not sure about the valve that is below ground. I wasn't thinking at the time to check but I assumed that if I closed that valve it would shut off water to the house which would do in a pinch but wouldn't work if we were staying in the home.

Do I have a problem and what should I do about it? Is there a reason that the above ground pipes are PVC instead of lead or copper?

 

[Mattguy]

I've owned a irrigation company here in Indiana for 22 years and my best advice is if you have a small compressor hook up a air hose to the pvb test port. Use the bottom port on the pvb. Then open up each valve one at a time. Twist the solenoid a quarter turn. This will get water out of pvb and valve assembly. The shut off valve should be for just the pvb. In the other pvc pipes there should be a drain port. We have special keys to turn off, but you can notch a piece of galvanized pipe and make your own. Hope I helped.

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[jimindm]

I do not have a sprinkler system, but by the looks of your pictures, there is likely a valve in side that will shut the water supply of. Somewhere in the line will be an air fitting that you use to blow any water out of the line. You will have to manually activate the valves in the second picture, using the control panel.

In Iowa irrigation companies use the large tow behind air compressors for this. High volume of compressed air is used.

If I did not understand what I was doing, I would call a company to come do it the first time. Watch intently and make notes, for doing it in the future.

On the bright side if it should happen to freeze and break somewhere, usually a home owner, can repair it.

 

[Mattguy]

This is one of my trucks. This is how we do it up north.

185cfm

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[CNGsaves]

Been blowing out my own sprinkler system for 15+ years. Only got burned once when we turned water back on too early in late February and wicked windy cold front came through and cracked my backflow valve with 20 degree temps.

Not sure by your pictures whether you have separate well for lawn irrigation purposes, or whether you are on city water. Can you post up more pics of any other side near the house??

Like above post says, use medium to large air compressor to blow out those lines. Turn off water supply (either well or city water) and use whatever method you have to apply air pressure. If all you have is schrader air valve (ie like valve stem on car), then I guess you could use it but they ****.

Instead, best method is use a port somewhere and get fittings to have an air compressor quick connect. Then just get pressurize the compressor, and connect hose to quick connect on sprinkler system at same time as you set control panel to turn on zone 1 for a couple minutes. When all water is out of zone 1 sprinkler heads, then change control panel to open up zone 2 sprinkler heads, etc until you've got all zones blown out. Make sure the last zone you blow out is the lowest zone physically on the entire yard so all water is out the entire system.

If compressor is strong enough (like 25 gal or larger) then you'll likely not have to wait on compressor to build up pressure between zones. Your little 3 zone system should not need one of those giant tow-behind compressors landscaping vendors use - - - way overkill.

Once all water is blown out of all below and above ground pipes, then replace the quick connect fitting with a plug. For any outdoor shut-off handles, be sure to leave those open, or at 45 degree angle so any water that's left can get out of ball valve. For any water in pipe leading up to backflow preventer (ie indoors), make sure you open any draincock so that water can drain out of there as well.

 

[kbs2244]

The key is volume vs PSI.
You need to keep the air blowing.
I see the jack hammer type compressors used ariund here.
I would call a service co to see what the charge would be.

 

[cgall]

Sprinkler system can not take high PSI, water pressure is only 40-50. Set your regulator to 40 PSI output, my 5 HP compressor easily blows out my 8-zone system, set each zone to 2 minutes and run thru them twice. Did mine last week and we have had several sub-freezing nights.

 

[CNGsaves]

Sprinkler system can not take high PSI, water pressure is only 40-50. Set your regulator to 40 PSI output, my 5 HP compressor easily blows out my 8-zone system, set each zone to 2 minutes and run thru them twice. Did mine last week and we have had several sub-freezing nights.

^ ^ ^ +1 as no need for super high pressure . . . just enough volume to push out water in minute or 2 on that zone.

Last year neighbor's oil-less 26 gal Craftsman did both his sprinkler system AND my 6 zone sprinkler system blown out in short time.

Absolutely no reason to pay someone for this simple task.

Heck, some years I've blown out system and turned on water early when no real winter weather arrived. Then a 'Northeaster blew in and re-did the sprinkler system blowout before the storm arrived. Thus, that year I blew out the system twice.

 

[jfdegnan]

Matt, the pvc test port looks like a 1/4" male flare. What do they actually call the brass bleeder valves that are opened/closed with flat blade screwdriver?

I had trouble finding a 1/4" female flare fitting to mate to that port to get to pipe to allow attachment to an air line compressor quick connect. Where might I find the 1/4" female flare fitting?

It might be easier to remove the small brass brass bleeder that terminates with the 1/4" male flare so he can blow it out and then reinstall bleeder valve.

Either way. I would think that the homeowner should be able to do this him/herself if they have even a pancake compressor.

Thanks for the help.

Jim

 

[gayler]

Sprinkler system can not take high PSI, water pressure is only 40-50. Set your regulator to 40 PSI output, my 5 HP compressor easily blows out my 8-zone system, set each zone to 2 minutes and run thru them twice. Did mine last week and we have had several sub-freezing nights.

Bingo! around 40psi is right. I shut off the water, hook up my are hoses and regulator and set my controller to run about five min per zone.

 

[Midnight_America]

Everything mentioned above is great advice. The hardest part is choosing a modality to connect the compressor to the system. These two warnings were already mentioned but well worth repeating: Isolate the system from the home/municipal water supply before blowing it out & make sure to leave all outside water valves in their open positions for the winter season.

 

[Simple Sam]

Thanks for the responses. I have some work ahead of me one my next trip to the house.

 

[sr71]

around here - $35 cash (185cfm unit is in and out) ...not even worth thinking about doing an 8 zone myself.

 

[stigedis]

Here in mn, the charge is $12.00 per zone and $5 hook up fee. My 8zone cost me $101.00. I am tired of paying this year after year when they come with pull behind compressor and it takes 10 minutes from start to finish. Guy always puts the fear in me that my 26 gallon, 160psi craftsmen upright compressor will not completely empty lines. He said volume is not great enough and as a result air will just skim over the water and not "push" it out. Is he in fact full of BS? Will my unit do the job? Lines are 1inch black pipe, with mostly saddle valves for heads. A few heads moved with 1/2 inch funny pipe. 8 zones with 4 heads each zone. Thanks for any info!

 

[AndrewDouglasBird]

I've helped my father blow his 5 zone system for the last 5 years now with a Craftsman 25 gallon compressor. We just hook up the air, turn the sprinkler valve on manually and when the sprinkler heads stop blowing water, we move to the next zone. If the tank drops below 50 psi or so, we wait for the pump to catch up then keep going. We also run through a second time to make sure. Never had a problem, even with sub zero temps.

The way I figure it, as long as the entire pipe isn't filled with water, even if it does freeze, there will be room for the water to expand but not burst the pipe.

 

[Mattguy]

Unscrew the flared test port, these should be fine thread 1/8 or 1/4. Congrats to all that winterize yourself, I've seen the damage first hand from home compressor blowouts. You spend 2500-4000 for a system, I think spending 70 bucks to make sure it's done right is worth it. Unless you have at least a 50-80 cfm compressor, the heads will pop up for a few seconds and go right back down. The unseen underground leaks from split elbows, risors, etc. That's what service calls are for!




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[CNGsaves]

^ ^ ^ Nice try Matt . . . . but law of physics and 20 yrs real-life experience has proven that there's absolutely no need for monster 50 to 80 CFM to blow out small residential sprinkler systems. If I had spent $100 a year to blow out my sprinkler system, I'd have burned $2,000 for no reason.

Especially for the OP's piddly little 3 zone system, a massive 50 to 80 CFM compressor might blow sprinkler heads clean out of the ground, or damage them. Also, any brittle PVC pipe subject to cracking might get blown out just like a hillbilly PVC airline system in garage would fail.

As earlier post indicated, hardest part is figuring out "port" that you'll use to get air into the system. For mine, the down PVC pipe below backflow preventer has union with a 1/2" threaded port that I just remove plug and screw in my quick connect that matches hose on air compressor.

Worst case scenario, the OP can cut the PVC pipe and re-do with union with 1/2" threaded hole and glue everything back together, especially if he gets frustrated with trying to find fittings for the 1/4" ports.

 

[Mattguy]

If you only have 3-4 heads a zone that's fine. I'm talking about 8-20 heads a zone. I do this stuff for a living, not just once a year for my house. 22 years experience, no need to make this **** up.

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[TireTracks]

And remember, you don't need high pressure less than 60 is good.

At work my boss got impatient and cranked the IR compressor trailer into full speed( over 120 psi).
Blew a toilet( winterizeing a park bathroom and sprinkler system) into toiled shrapnel and blew a sprinkler clean off the cast iron t it was stuck on and launched it 30ft in the air.

 

[CNGsaves]

Agree Matt, that your monster compressor is perfect for big business sprinkler systems, or golf courses, etc. However, it's way overkill for the OP in Reno, NV who only has piddly 3 zone sprinkler system.

There is greater probability that super high air pressure WILL damage the OP's piddly little system and he will have water leaks next year caused by the winterize air blow out.

Weather in Reno, NV is very mild anyway as I researched what weather service has recorded for average lows and highs. Looks like only about 4 months during year even drop below freezing (Nov thru Feb, with March being borderline). See at:
http://www.weather.com/weather/wxclimatology/monthly/graph/USNV0076

 

[jerseywild]

I set my zones for 2 minutes each and run through each zone twice. The compressor is just a small craftsman 220volt 5hp. The second go around is really not needed since all the water is cleared on the first round. It takes more time to run the hose and hook up.

 

[gball]

If no one has already said it, don't leave the ball valves on the back flow fully open. Set the at a 45. Fully opening can trap water on the sides of the ball causing the outer housing of the valve to crack.

added... that goes for the bleeders as well.

 

[Falcon67]

I'd offer advice, but I have water here during winter. All I do here is shut off the pump and let the water out of the faucet risers.

 

[Mattguy]

I love to winterize!

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[Mattguy]

Here is how to put valves.

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[James E]

Thankfully, all of the zones of my system are above the backflow so gravity draining handles my setup.

I do wonder though, wouldn't it be a good idea to have disconnects on both sides of your backflow valve? Since it's above the ground in an area where you have hard freezes. The darned things are so expensive that instead of worrying about the residual water in them freezing, most of my neigbors and I just remove them in the winter, move them into the garage and reinstall them in the spring.

Plus, removing them reduces the possiblility of them being stolen by about 1/3 (4 months in the garage out of 12).

 

[AirJunky]

Bingo! around 40psi is right. I shut off the water, hook up my are hoses and regulator and set my controller to run about five min per zone.

Just did it last night. My wife gave me a 33 gallon air compressor for Christmas last year. Then I built a soundproof enclosure for it in the garage. It was sure nice to just flip on the compressor, pull the air line out to the yard, & manually go thru each zone till they were all blowing air.

 

[gball]

James, I am in northern Michigan, it was 19 deg. here already yesterday morning and we have already had snow too. I work for a friend that has a Irrigation company. Out of the 400 or so blow outs we did this year, about half of those being non-pump systems with a back flow, i think there are two customers that have us pull the back flow. I guess it can't hurt it unless it gets broke taking it off and on, but don't see the need especially in a warmer climate than here.

 

[Mattguy]

No need to pull pvb. Rpz yes.(double check)

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[Mattguy]

Just wondering, people who have systems winterized professionally, what are the companies charging? We charge $70 for up to 12 zones.

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[gball]

$60 for a standard hook. Some are a double hook, We have one that is one hook but 6 controllers and a lot of walking... so 60 and up.

 

[hedhunter9]

around here, $50-60. But we got a card in the mail from "Bills Irrigation" that does it for $35 and if several in one area, will do it for $32 each...
Bob

 

[rponfick]

I see recommended above using only 40-50 lbs pressure to operate your sprinkler system. Around my neck of the woods the home improvement guys on tv/radio recommend using more water pressure to operate the sprinkler system. They suggest tying sprinkler connection into city main supply ahead of the pressure reducing valve you have for household appliances. They say you get more water out and better coverage.

This winter I am thinking of re-connecting my system to operate ahead of the house reduction valve. I normally blow out my system with my 130 lb. max compressor, and I have never damaged anything. I would not use this much pressure on my sprinkler system, but I think 75-80 should be OK. Plan to plumb additional pressure reduction valve in the new system connection just in case the pressure is too high.

Am I asking for trouble? Ralph

 

[RickP]

I wouldn't go above 50 or 60 psi air pressure on my system, but you can do what you want on yours. Just remember that air pressure is harder on piping than the same water pressure (water is non-compressible).

I just winterized my system with a 5hp 60 gallon compressor. It took a LOT longer than with the tow behind compressor (15 zones) but it cleared out all the water.

 

[sailah]

Hoping for some advice here. New homeowner and working through the winterizing steps I need to take. I have a 12 zone sprinkler system with 1" black plastic pipe.

Here's a pic of the RPZ (at least that's what I think it is) as well as what I think is the blowout port.





From my exhaustive internet research and YouTube watching, I'm now educated enough to be dangerous

I've heard the horror stories about small compressor setups, I have an 80 gal 2 stage Jet Air as well as a 40 gal HF spare compressor I can gang together. I know it's not tow behind CFM, but is this workable?



I plan to shutoff the water using the yellow handle ball valve in the top pic. Turn off the right Watts ball valve. Hook up air to blow out port which is 2' upstream of that Watts valve and cycle through the zones using my Hunter Pro-C controller for 2 minute intervals.

After that, what else should I do with this RPZ valve? I have no idea how to drain it. Leave the valves 1/4 turn open?

Thanks

 

[kbs2244]

What is the frost line in Reno?
Freezing air temps do not always mean freezing ground temps.
Ask around.
You may not need to do it at all.

 

[sailah]

I'm in Hingham MA. Def gets freezing here. The valve is under the barn in a stand up crawl space. Out of the weather but no heat in there. I would have to think it would get below freezing during the depths of winter

 

[CNGsaves]

^ ^ ^ Sailah . . . what is the source of water ?? This from a well or city water ??

ALL . . . absolutely all . . water that's down there needs blown out, not just water beyond the yellow handle shutoff valve on left side. Did prior owners just take the chance that copper water pipe wouldn't freeze that is BEFORE the shutoff valve ?? With strange weather we're getting, I would not take that chance in your climate. Deep freeze storm of 10 below zero could freeze EVERYTHING in the crawl space.

Either compressor will be fine.

Upstream (BEFORE water gets above ground to the yellow handle shutoff), see if there's shutoff and blowout port so you can blow out that segment also all the way through backflow valve.

Take out plug and get plumbing fittings so a quick connect air male fitting will be screwed in there. That way your air compressor hose with female quick connect just snaps right on.

 

[sailah]

Thanks. The barn has an apartment above it so that water stays on. What you see to the left feeds to mechanical room and up to "living" space. It's a different water feed than my house. Both are city water.

Plan on blowing out this weekend with the warm weather.

It's been this way for a decade in an unheated space. Not sure what else I can do for it.

 

[CNGsaves]

Crawl space probably stays warm enough then to "protect" water supply up to the shutoff.

Once you shutoff water and blow out all your sprinkler lines outside, I'd leave plug out - - - with reminder note to yourself to put in next spring when you turn on water again !!

A cheap makeshift solution to prevent any freezing down there is build "HOOD" structure from 2x4's and plywood shaped like a tent. Close up ends with tarps or custom shape wood around the pipes. Just lay trouble light on ground with 75w Edison light bulb that you turn on when temps are low. Lightbulb will create enough heat that the cozy "tent" area with pipes won't freeze.