Full scene restart

Hey guys, so I got this small game I am working on and I am using PoolManager, I am not getting any errors but when I use my restart button using this code...

 using UnityEngine;
 using System.Collections;
 
 public class FullRestart : MonoBehaviour 
 {
     void OnClick()
     {
         Application.LoadLevel ("Level_1");
     }
 }

I am not getting it to again start the enemies to spawn, they don't spawn ever again and I am not getting any error. The code for my spawning enemies is this and its set to false until I press a button in game...

 using UnityEngine;
 using System.Collections;
 using PathologicalGames;
 
 public class EnemySpawning : MonoBehaviour 
 {
     public float spawnTime = 3.0f;
     float timeLeft = 0.0f;
     public static bool isSpawning = false;
     
     public Transform español = null;
         
     void Update () 
     {
         if (isSpawning != false)
         {
             timeLeft -= Time.deltaTime;
             if (timeLeft <= 0.0f) 
             {
                 Transform t = PoolManager.Pools["Enemy"].Spawn(español, transform.position, Quaternion.identity);
                 
                 timeLeft = spawnTime;
             }
         }
         
     }
 }

So if you guys ever faced a problem like this please I would love to get some help, thank you all in advance!