Temperature Control Switch on a Water Heater‌

The ‌temperature control switch‌ on a water heater operates through ‌mechanical or electronic mechanisms‌ to precisely regulate water temperature. Its core functions include ‌temperature sensing, circuit on/off control, and safety protection‌.

I. Working Principle of the Temperature Control Switch‌

Mechanical Temperature Control Switch‌

Uses a ‌bimetallic strip or thermal sensor tube‌ as the temperature-sensing element.

When the water reaches the set temperature, the metal strip bends, breaking the circuit and stopping heating.

After cooling, the contacts reset and restore power supply.

Some models (e.g., KSD302) are ‌normally closed (NC) switches‌, conducting electricity at normal temperatures and automatically disconnecting when overheated.

Electronic Temperature Control System‌

Adjusts temperature via a knob, which changes the internal spring pressure.

A ‌thermal sensor tube‌ detects water pressure changes and controls the contact state.

The tube must be installed at a fixed position (e.g., 12 cm near the heating element) without bending, as this affects temperature accuracy.

II. Fault Detection & Maintenance‌

Continuity Test‌: Use a multimeter (buzzer mode) to check if the switch conducts at room temperature. When heated to the set temperature (e.g., 93°C), it should automatically disconnect, then reset when cooled.

Installation Precautions‌:

Turn off power and water supply before replacement.

Reconnect wires in the same order or reassemble the valve properly to avoid leaks.

For ‌gas water heaters‌, ensure the ‌air pressure switch tubing‌ is correctly installed.

III. Common Issues & Solutions‌

Temperature Adjustment Failure‌: Check if the thermal tube is misaligned or damaged, or if the mixing valve core is clogged.

Frequent Tripping‌: Verify if the temperature switch activates correctly or if the circuit is overloaded.

This summary provides a clear guide to ‌how water heater thermostats work, how to test them, and how to troubleshoot common problems‌. Let me know if you need further details!