Pipes sometimes bang when sprinker system comes on

Pipes sometimes bang when sprinkler system comes on

I've done a search and understand the problem is likely water hammer but am at a loss what is causing it.

When the sprinkler system comes on at 3am the pipes in the kitchen sink bang VERY loudly. However, this has just started recently and doesn't happen each time the sprinkler comes on. In the last month it has happened twice (2 times out of 12 times the sprinkler system came on.)

The banging stops as soon as I turn the sprinkler system off manually.

The kitchen plumbing has a reverse osmosis water filter and the refrigerator ice maker connected under the sink.

Thanks for any ideas.

quote; The banging stops as soon as I turn the sprinkler system off manually.

Does this mean the noise is continual when the irrigation is working? IF so, the problem is usually with the valve itself. IF it only occurs when the valve opens, then it is often caused by the valve opening too quickly for the water to overcome inertia and begin flowing.

Yes, it starts when the sprinkler system comes on and bangs continuously until I turn the sprinkler off manually. One thing to be aware of is that each station cycle is only three minutes (requirements of living in the desert - have to water slowly to prevent runoff). So the definition of 'continuously' may be different for a 3 minute cycle vs a 15 minute cycle.

So, to make sure I understand, one of the sprinkler valves may be causing the problem? If so, do you have an idea on why this would be occurring randomly? Is the valve possibly going bad?

There could several reasons why it happens, ranging from a failing valve, to a transformer in the control box that cannot keep the valve open continually, so it closes and then opens again.