diff --git a/succbone/succd/modbus.go b/succbone/succd/modbus.go
index a4d05e0..70fa22f 100644
--- a/succbone/succd/modbus.go
+++ b/succbone/succd/modbus.go
@@ -101,6 +101,11 @@ func (d *daemon) modbusUpdate() {
 		// TODO: Input mapping goes here
 	}
 
+	// We must wait between reading and writing to the -KEC1 relay board
+	// because otherwise it chokes and times out the write registers
+	// command.
+	time.Sleep(time.Millisecond * 10)
+
 	// KFA1-KFA8
 	var relayState [8]bool
 	d.mu.Lock()