| My irrigation system pipes just started humming when the automatic zone-valves cycle off. Any idea as to what is going on? Is it a defective anti-syphone valve? |
| It could be a faulty anti-syphon valve, or it could be that the water is draining slowly before it bubbles out of the sprinkler head; perhaps because there's air in the pipes. You can try flushing the pipes out to see if that fixes the problem. If not, anti-syphon valves are relatively inexpensive. I'd replace it. |
