Step1: Disconnect power at breaker to prevent electric shock and verify voltage is isolated.
Step2: Remove control panel and note wiring configuration, document connections carefully.
Step3: Disconnect old switch and install new infinite switch kit in same orientation, avoid damage to terminals.
Step4: Reconnect wires securely per diagram, ensure terminals tight, double-check grounding.
Step5: Reassemble panel, restore power, test heat control function and confirm smooth temperature control operation.