SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

It will not prevent backflow. Many use it just for an added protection. Unless you have a poly mainline, I really see no use of having a master valve.

I agree with RVLI. There are pros and cons with the master valve. Usually your system is running early in the morning. Unless you check your system every so often you will not know if you have a problem like a stuck valve or a main line leak until your lawn start to show indications of a problem. Then it will act like a bandage. The problem is still there but you just won't see it. On the other hand, if you go on a 2 week vacation and a problem occures it will not be a continues problem until you get back. Examples: stuck valve running 24/7 for 1 week staight or a main-line break. That would be a problem unless you have some very good neighbors who will watch out for you and will know what to do if something happens.

Not wanting to start an arguement here, but I disagree. A master valve is a plus for for your system. The cost is minimal and piece of mind is hard to beat. But to each his own.


SamIV

A master valve is not necessary at all, infact its just another thing that may go wrong. There are certain situations that require this, howevery installing a master valve on a new installation is not necessary

I am of the new way of thought and believe that a master valve is an awesome idea. I walked through a yard two days ago that made my mind concrete! This guy lived out of two homes. One in the USA and another in Italy. He was offten gone and never had time to check his sprinkler system. He returned a week ago to a crator sized hole in the side of his house. His neibors just looked on as if nothing was wrong. His water main had been running for six straight days! it was quite the site. For less than a hundred dollars he could have really saved himselfs some time and effort. Master valves are a definite Plus. Never put a system in w/o it!

Well, I'm gonna vote against a master valve. Main reason is that if you have a master valve installed, you force a homeowner to be available whenever service is required. As a contractor, that restriction would make doing service work very difficult from a scheduling perspective, and at peak times, would force customers to go without their system for a substantial period of time. I do put a manual shut off valve on the outside of the house so that the water to the irrigation system can be turned off in an emergency (or if the valves need service), but a properly installed and maintained system isn't going to spring a leak for no reason.

I'm going to respectfully disagree with bobw. So long as the master valve is installed outside (right where all the rest of the valves are installed), then the only issue a master valve creates for servicing is just making sure the contractor is aware of its presence (so they don't start trying to "fix" a valve that's "not working").

Otherwise, I definitly see the benefit of a master valve to reduce the troubles caused by a valve that gets stuck open. I know that half my irrigation system is for drip irrigation, so if something gets stuck open, I might not know it for days.

Here's a quote from the www.irrigationtutorials.com (the internet bible for irrigation as far as I'm concerned) on the subject...

<i>Actual master valves are used on very sensitive irrigation systems where a valve failure might cause enormous damage, such as a steep slope. If the valves were to stick "on" the slope might wash out. No need for them on the average irrigation system.</i>

Otherwise, the only other comment I think I've heard on this issue is something like some people have timming problems with automatic master valve. I don't remember the specifics, but its something about having difficulties getting valves to properly work when you have two of them in series.

I'd rather spend the master valve money on valves with flow controls, if I wanted to chase some extra reliability.