I have a 50cm x 50cm x 80cm water tank and I am heating water with two 1500 watt water heater resistances. I think they are stainless steel or chrome plated but I am not sure about it, I can't contact with the manufacturer. Also, they work at 220V AC.

My question is how do I know that there is an electrical leakage in the water in case of deterioration of the coatings of resistances?

Can I simply measure it with multimeter, like one probe connected to the ground and other is in the water? Or can I build a circuit that will alert me if there is a electrical leakage?

  • \$\begingroup\$ Single phase or split phase? \$\endgroup\$ Dec 25, 2019 at 8:28
  • \$\begingroup\$ @Jasen Single phase. \$\endgroup\$ Dec 25, 2019 at 8:48
  • 3
    \$\begingroup\$ Surely the heater elements have an earth connection on the element casing? That will direct any leakage current to earth. \$\endgroup\$
    – Transistor
    Dec 25, 2019 at 9:45
  • \$\begingroup\$ @Jasen Product looks like this one. timg.china.cn/3/1_12_53718_600_600.jpg I can't see any grounding at plug side. Is it possible for it to be grounded inside? \$\endgroup\$ Dec 25, 2019 at 11:41

1 Answer 1


This type of heater has a thin resistance wire inside a stainless/inconel/other corrosion resistant metal tube, insulated by a ceramic.

These elements normally have some leakage, especially as they age.

Measuring the leakage to the water is hard. You'd have to measure the two phase lines, accurately, and subtract to the the difference, or use a doubly wound transformer coil like in an RCD. Or isolate the water and put a resistor between the water and ground.

I expect for your purposes, earthing the stainless tube is you're best option, then any leakage will flow to earth, hazards avoided...


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.