I mention summer because that is when we have water turned on to the irrigation system. Actually, it doesn't immediately start humming each year; this year it took about two months before the humming began.

If I turn off the water to the irrigation system the humming stops. When I turn the water back on, the pipes bang briefly, then after that all the sound coming from the pipe is the humming.

The humming is more of a middle to high range. It fluctuates, medium to high back to medium. Kind of like a siren. Actually sounds more like a dying cow.

Yes, I live in a northern climate.

When the water is turned on to the irrigation system and the system is actually running . . . there isn't any sound. As soon as the system operating cycles end, the humming starts. If I turn off the water to the system it also stops.

Thanks for your interest!

Hello,

Does your system have a boiler drain on it, if so does it have a atmospheric breaker on the hose part of it?

Below I am going to give you a link to my blog where I will post pics for you to look at of what I am talking about. I have seen two similar situations in the past few years and both had something in common.

You mentioned that you turned the water off and when you turned it back on the pipes banged for a bit. Did your timer go through any cycles while the water was off or was your timer off the entire time your water was turned off? If the timer and water were both off it sounds like you either have a small leak in your mainline or even more likely that you have a weeping valve since the mainline had to fill up with water.

It is currently 3pm est. Please wait until after dinner (after 7pm est) for the post on my blog w/ pics. I will then list a pic and the noises that I have seen from each device and how to eliminate the noise if they are the cause

Here is a link that might be useful: lawn sprinkler Blog w/ pics of parts for dbowers humming noise

Bob, I believe the source is the boiler drain. Bsaed on sound, and vibration, this appears to be the source. However, I am scared to attempt to tighten it any further as I have a past history of over tightening and breaking things. I will contact a plumber to see if the drain needs replaced. Thanks for your help.

Here is the link for the Dbowers pics if anyone else has a similar problem. The link in my above post just goes to my current subject of my blog. This link will take you to the Dbowers issue.

http://www.rilawnsprinklers.com/blog/2009/07/dbowers-question-regarding-humming.html

Here is a link that might be useful: Dbowers irrigation issue

when my sprinkler system came on i heard and felt a vibration near one of my toilets after i changed the faulty fill volve in my toilet the noise / humm humming has gone away