Discontinued: This item has been discontinued by the manufacturer. Remaining stock is available while supplies last.

The Gecko in.Therm 4.0kW Heater Tube (0603-421002) is a heating component designed for Gecko spa systems, delivering consistent water temperature.

Specifications:

• Brand: Gecko Alliance
• Power rating: 4.0 kW
• Part no: 0603-421002

Fits/replaces:

• Gecko spa systems using this heater tube platform
• Replaces part number: 0603-416001
• Replaces part number: 0603-409001

Common signs you need this part:

• Spa won't reach or hold set temperature
• "Heater failure" or flow-related error code on the topside display
• Visible corrosion or mineral buildup on the existing heater tube

Returns & installation: Heaters are electrical components and are non-returnable once opened, per our Terms & Conditions. Professional installation is recommended.

FAQ

Is this part still in production? No — it has been discontinued by Gecko. This listing reflects remaining stock only.

What older tubes does this replace? It replaces part numbers 0603-416001 and 0603-409001.

Can I return this if it's the wrong part? No — heaters are final sale once opened, so confirm compatibility before ordering.