Tech support from Eco-smart say you need two inputs (two hot wires) 120 volts each but no neutral making 240 volt. Here in Australia we have 240 volts which is Active (Red) Neutral (Black) and Earth (green/yellow). So will I need a transformer? Even my electrician is scratching his head!

  • I suspect that it will work fine with that voltage difference between the two wires, but a bigger concern is that Australian electricity is 50 Hz, while the heater might be expecting 60 Hz. Jul 27, 2019 at 1:00
  • 2
    If it's a heat-pump type with a motor, this is a valid concern. If it's a resistive heater it's a non-issue.
    – Ecnerwal
    Jul 27, 2019 at 1:05
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    How many kW is this Ecosmart? The largest ones may simply be too large for 5-continent residential services to handle... Jul 27, 2019 at 3:57
  • @Ecnerwal, "Ecosmart" is just branding. all their electric heaters are resistive
    – Jasen
    Jul 27, 2019 at 5:26

2 Answers 2


Apart from the question of whether it's got the appropriate certifications, etc. to be installed in Australia, which is a legal rather than practical matter...

It's a 240V-only appliance, it should be just fine. It is normal for everything operating on the US supply at 120V from ground to be rated for 250V to ground, so the insulation (electrical) should be safe with a 240V single-sided supply rather than a 120-0-120 supply. But your local electrical and/or plumbing inspector may object if it lacks the correct documentation for the local area.

  • maybe he wants to connect it to his 415V three phase supply? the ecosmart documents are a real mess when it comes to multiphase
    – Jasen
    Jul 27, 2019 at 5:36
  • Did you Read The Question? You know, the one that SPECIFICALLY MENTIONS 240V? On two wires + ground? I'm guessing not. Try doing that.
    – Ecnerwal
    Jul 27, 2019 at 15:46
  • Jasen's query is reasonable since 5-continent 240V power is supplied as 1, 2, or 3 phases of 415V 3-phase wye. This is why many on-demand water heaters have 3 banks of heater. Hooking them up "wye" if possible is vastly preferred, since it evenly loads the transformer. Jul 28, 2019 at 22:09

If boiler is resistive type and no neutral is required on the boiler itself you sould be able to install it across live and neutral with live on L1 and neutral on L2 (it still have 240V across the two terminals) and also frequency (50 vs 60Hz) won't be an issue. If it's heat-pump type (with a motor in it) it probaly will not work.

  • These comments help greatly - I think we are 50/60 hz. Thanks DDS and ecnerwal- It is wired ready to go just nervous about turning it on. Jul 28, 2019 at 4:49

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