Replacing a Heat-Damaged Hardie RD-600 Sprinkler Controller in Arizona

The Hardie RD-600 controller’s display failed after prolonged Arizona heat exposure. The unit unplugs easily, making replacement straightforward. Here’s what to do:

Where to Buy a Replacement

• Big-box stores: Lowe’s, Home Depot carry Rain Bird, Hunter, Orbit controllers (Hardie is now Irritrol).
• Irrigation supply houses: Ewing Irrigation, SiteOne, John Deere Landscapes—staff can match your wire count and features.
• Online: Amazon, Sprinkler Warehouse, DripWorks. Search “6-station irrigation controller”.

Installation Tips

1. Photograph the existing wiring (label each wire with zone number).
2. Turn off power at the transformer (usually a plug-in near the controller).
3. Disconnect wires, remove old controller, mount new one.
4. Reconnect: common wire to “C” or “COM”, each zone wire to its numbered terminal.
5. Plug in transformer, set date/time, program schedule.

Prevent Future Heat Damage

• Mount the new controller indoors (garage, laundry room, utility closet) if possible.
• If outdoor mounting is required, choose a shaded north/east wall.
• Build a simple shade hood: a 12×12″ plywood roof on brackets, painted white.
• Consider a smart controller (Rain Bird ESP-TM2, Hunter Hydrawise) with a weatherproof cabinet rated for direct sun.

Total cost: $80–$180 for a basic 6-zone controller; $200–$350 for a smart model. Installation is DIY-friendly if you’re comfortable with low-voltage wiring.