Water Hammer in the House from a Sprinkler Valve Opening

This residential home has a sprinkler system that connects to the utility water line at the street. The water supply in the garage shakes violently when the sprinkler zones in the yard turn on. This “water hammer” can be heard throughout the whole house.

I was able to isolate the problem to the water heater expansion tank. When the pressure drops at the street from the sprinkler valve opening, the pressure tank would send water backwards in the system. As the pressure builds back up, the back and forth caused water hammer or violent shaking of the pipes of the water supply lines in the house.

The issue was remedied by installing a dual back check valve before the pressure regulator right after the water supply line shutoff in the garage.

[quackassassin]

Always happy to see someone still using a torch