Step1: Disconnect electrical power and verify zero voltage using a multimeter for safety.
Step2: Remove access panel and document existing wiring connections before disassembly.
Step3: Detach faulty thermostat assembly carefully to avoid damage.
Step4: Install new unit in position ensuring secure fit.
Step5: Reconnect wiring exactly as noted, matching labeling.
Step6: Secure mounting hardware and replace panel, tighten screws.
Step7: Restore power and test temperature control accuracy, verify calibration.