Troubleshooting Toro TMC 212 After Lightning Strike: Sprinklers Won't Shut Off

Lightning Strike Causes Sprinkler System Malfunction

A homeowner reports that lightning struck between two houses, causing all sprinklers to activate and refuse to turn off. The water supply was shut off, and the controller display is blank despite 120V power reaching the control box.

Diagnostic Steps

First, power off the controller completely, then turn the water back on. Observe the valves:

• If valves stay off: The problem is the controller itself, which likely needs repair or replacement.
• If valves activate with controller powered off: The issue lies in the valves, probably fried solenoids.

Next Steps

This simple test isolates whether the fault is in the controller or the valve solenoids. If the controller is at fault, consider professional repair or upgrading to a modern unit like an Irritrol Rain Dial or Rain Bird ESP series. If solenoids are damaged, replace them individually. Always ensure power is disconnected before inspecting wiring.