What coolant should I use in my Miller Coolmate 4 cooling system?

For GTAW welding or where high frequency current is used, use Low Conductivity Coolant (part 043810), distilled or deionized water (above 32°F), or Aluminum Protecting Coolant (043809). For GMAW welding or where high frequency current is not used, you can use Low Conductivity Coolant (043810), Aluminum Protecting Coolant (043809), or distilled/deionized water (above 32°F). Do not use conductive coolant. Using any coolant other than those listed voids the warranty on parts that contact the coolant.