What is involved in turning a inground, home lawn sprinkler system on? Last fall we had the system ‘blown out’. I wasn’t there, so I don’t know exactly what the guy did. I assume he shut off the main valve, opened the drain valve, and then pumped compressed air into each sprinkler head.
I found the main valve to send water to the system, but are there other valves that might be turned off? Specifically, are there valves in those little green boxes that are burried in the yard? They don’t look like they have been opened recently, so I am guessing I just need to kick on the main.
Is it likely that there is a seperate main valve for the front and back yards?
I just did mine over the weekend. There is one main valve. When you turn it on you hear the water rushing in to prime the system. I have seven different zones but I just need to flip the one valve. There are not separate valves for each zone, or if there are, the service guys did not turn those off.
The easy way to find out is to start the system up and see if it feeds all the zones (sounds like you have two, front and back?).
You’d think, having grown up in some of those snowy places, I would have remembered that. Here, we just cut back the watering to two or three times a week during winter.
Mine doesn’t have shutoffs in the sprinkler heads. There might be a shutoff in the backyard and front, I’ve never checked. Is your’s computerized, or just a manual turn-on switch? My timers need complex programming.
I never would have suspected that graduate degrees in computer science would come in handy for watering my lawn.
There are likely small petcocks on the Vacuum Breaker and or check valve (backflow prevention). These may have been left open after the blow out, but it’s not likely.
Also, in each valve box, it is likely that there is one drain valve. If you have more than one valve box, there may be a drain valve on the main line between them. They would be accessible though a little ‘valve box’ or a little cover about 3” in diameter that can be removed. Then there is a special tool to use to reach them to shut them off (if its two small for your hand).
I used to design and install these things. And if you do it right, there is really no need to blow them out (it’s not a bad idea though).
Go to back flow preventer. Ensure all drains are closed. Ensure all valves are closed.
Go to water supply valve ( located where your house water is diverted to the sprinkler system, usually near the backflow preventer (which is just outside the house water supply). The water supply valve is probably inside the house, but close to the backflow preventer which is outside the house.
Backflow preventers ‘prime’ in different ways. Some, you just run on the water and it’s primed, then you turn on the valves at the backflow preventer, then just use the comp control to turn on the zones.
Some backflow preventers require you to turn on the water suddenly, or slowly and then turn on the valves in a certain order. If the backflow preventer doesn’t leak out the top, you are good to just turn on the valves.
Thanks a lot for everyone’s help. I tried Sailboat’s idea first, but my sprinkler system ‘wasn’t in the mood’. So I read the rest of the posts and the link. My system was pretty easy, I turned on the water shut off valve then the computer control and the water started pumping. I guess the backflow preventers primed themseleves.
What is the key to creating a system that doesn’t require a blow out? Are sprinkler systems more forgiving than say standard plumbing pipes?
Getting a professional (such as myself) to do it is the way to go. A pro will observe the operation of each sprinkler head and is better than you are at spotting problems and repairing/adjusting.
Last week one of my customers turned on his own system. There was a drain valve he didn’t know about which was left open all night and his crawlspace ended up with quite a lot of water in it.
Does this mean the feeds to the sprinkler heads will automatically drain into the ground when the water is shut off? Wouldn’t there still be a problem between the house and the backflow preventers? Or do you still do the drain-out for that line, but not the blow-out for the lines in the yard?
Was this a drain valve left open from the previous year’s blow-out? Or was this a valve he opened in the process of turning on the system?
