Think your spa heater element isn't working? Here's a few very basic things that can be checked (by a qualified person). This is all for 220-240V systems. As with any electrical diagnostics, this is a very rough guide, and manufacturer's specs should be used. This is no-means everything to be checked, but a very basic run-down! 

Note that heaters use varying methods of 'activating' such as dual temperature probes (testing In vs Out temp differential), pressure switches, flow switches, vacuum switches, or optical water sensors. These must all be checked to be operating before doing the following:

  • Ensure spa is connected to an RCD (Safety Switch). This is for safety, and is required by Law in all States of Australia. Just last year, a man was electrocuted to death, where a simple safety switch would have saved his life.
  • Remove filters.
  • Check pump has plenty of flow, and ensure impeller is clear.
  • Ensure sufficient water flow from suctions/filter area, and back to the spa.
  • Disconnect power, and inspect heater element and terminals. Any rust, corrosion, coating-damage, or discoloration can suggest problems. (if it appears 100% OK, go to next step.
  • Using a multi-meter, check that 220-240V AC is going to the element terminals (if so, continue. If no power, you may have other issues. You can send control system to us, including touchpad) 
  • Test amperage draw from one post of the terminals. They should approximate the following. (if so, continue. If they are out of that range, you may have other issues. You can send control system to us, including touchpad) 
    • 1kW=~4.3A,
    • 1.5kW=~6.5A,
    • 2kW=~8.7A,
    • 3kW=~13A,
    • 4kW=~17A
    • 5.5kW=~24A
    • 6kW=~26
  • Remove power, and disconnect heater. 
    Test resistance between the element terminals. They should test close to the following. (if so, continue. If they are out of that range, you may have other issues. You can send control system to us, including touchpad) 
    • 1kW=~52Ω
    • 1.5kW=~35Ω
    • 2kW=~26Ω
    • 3kW=~17Ω
    • 4kW=~13Ω
    • 5.5kW=~9.5Ω
    • 6kW=~8.8Ω 

If any of the above are out of acceptable range, you may have an element issue. There a dozens of varieties of elements, and there always is a possibly of other problems, such as a faulty relay/contactor, power issue, control issue, etc. 

  • An electrician should also test for earth leakage, and other electrical faults.

If in any doubt we always recommend to have the control system disconnected and sent to us at:

Heater & Spa Parts
Factory 1 / 10 Industry Blvd
Carrum Downs, Vic 3201

Failures of heater elements can be caused from corrosive water (common when using Bromine), calcium, age, dry-firing, and even ferrobacillus bacteria!