Today we’re going to look at electric water heaters, primarily for swimming pools although the smaller ones can be used in spas as well.

This particular one can be wired as three phase or as single phase, the star points are connected together for three phase and the three separate phases go onto each terminal.

The control systems incorporate a thermostat, an overheat protection stat, and inside the inner-tube a flow switch.

These three items should be connected as per the manufacturers recommendations to a system of two contractors.

If you get any problems with the heater the first to check is to see if there’s any earth leakage from the elements.

To do that you need a meter such as this one,a 500 volt insulation tester, and you clip one end on to the earth terminal, making sure the supply is fully isolated and disconnected, and then simply test each element in turn to see if there is any leakage to earth, and on this particular heater there is no problem swith the elements with regards earth leakage.

The next thing to check is to check the continuity of each element, to do that you need an Ohm meter, such as this one.

Clip the common onto the star point of the elements and then again, simply test each element in turn, and as you can see there’s only one element with any continuity, the other two are completely open circuit and have failed.

It is very important to make sure that the control systems are connected to the manufacturers recommendation.

If a heater such as this plastic body type was used without the correct flow, and the flow switch not working, this complete body would melt in seconds.

So it very important to make sure that the control systems are connected correctly.

If you have any more questions or require any more help with water heaters, please don’t hesitate in contacting us.