Heater failure

Describe nature (details) of failure. What is your line voltage? What is the heater voltage rating? Does your heater respond accurately to the thermostat settings? Is the heater that fails the original type heater supplied with the water tank. Have you contacted your solar heater manufacturer and discussed the problem with them?

Some possible causes:

1. The actual voltage is higher than the heater's rated voltage.

2. The heater sometimes becomes unsubmerged (either from drop of liquid level or from boiling).

3. The watt density of the heater is higher than suitable for the medium. For water, a maximum of 45 w/in² rings a bell, but this should be rechecked.

4. The heater was intended for insertion into a pipe (circulating liquid) rather than into a tank (static or very low velocity).

Do you have dielectric unions installed on the copper pipes connected to the water heater? Possible electrolysis due to ground leakage...

Chesk pH of the heated water from solar panel/ Raw water.

Go for analyss of feed water.

Acidic pH can speed up corrosion.

If more anions like cholides, sulphates present in raw water, that can also add to speedy corrosion

Is the output voltage from the panels properly regulated?

If not, then as one heater comes up to temperature and the thermostat switches it off, the reduced load may cause the voltage to rise, thereby shortening the life of the other heaters.

Please try to be specific on the type of failure to enable a quick and direct responce.

Dickson.