mixing valve that is not set to hot water, etc.
Temperature pipe contacts heating pipe or these two pipes are connected upon being covered by water
scale. In such a case, heat of heating pipe is directly transmitted to temperature sensing probe of
temperature limiter, thus resulting in faulty action. Actually, the water temperature is not high
adequately. Therefore, it needs to replace the heater.
Check whether operation is proper → Check whether power supply is electric → Open
overhaul cover
and whether wiring junction comes off → Check whether temperature limiter is running → Use a
multimeter to measure the circuit break between temperature limite
r and heating pipe → Measure
whether heating pipe is disconnected
Repair method:
1.
After excluding the likeliness of misoperation, pull the plug, measure whether the socket is
electric with a multimeter and measure voltage of all pins of the socket by the way, so as to
ensure null line on the left, live wire on the right and earth wire in the middle;
2.
Dismount maintenance end cap with hex screwdriver, switch on temperature controller and set
regulating power to grade 3 (if any) and measure with a multimeter whether the line from two
pins to heating pipe are conductive; if yes, it is preliminarily judged as damage of heater; then,
check whether the rest button in the middle of temperature limiter trips out; if yes, reset it
correspondingly; then, check whether temperature controller and switch work normally;
3.
If power of heating pipe is in reverse proportion to resistance, measure resistance to judge
whether the heater is normal; for instance, the resistance of 1500W heater shall be: R
＝
U*U/P
＝
32.3Ω;
4.
To judge whether hydraulic expansion typed temperature controller works normally, it needs to
place temperature sensing probe of temperature controller into a cup of water around 50℃, make
counterclockwise rotation to its end, measure that both ends are switched off, and then gently
adjust it to its high-temperature end along clockwise rotation. A normal temperature controller
will resound a slight "crack". At this moment, both ends are conductive; otherwise, the
temperature controller is faulty;
5.
If no problem is found through above procedures, use a multimeter to measure whether
input/output terminal of the switch is conductive, thus excluding the switch failure;
6.
In addition to above reasons, non-heating failure of an electric product generally results from
damage of components such as relay or electric transformer, so the output voltage of relay is null.
At this moment when other failures are excluded, priorities shall be given to cause of failure of
electrically-controlled board, so as to identify the component that is required for replacement. If
