Appliance Repair Glossary

Understanding these terms will help you diagnose error codes, follow repair guides, and decide whether to DIY or call a professional.

Error Code

An alphanumeric code displayed by an appliance to indicate a specific malfunction. Each brand uses different code formats (e.g., Samsung uses letters+numbers like tE, LG uses abbreviations like OE).

Control Board

The main circuit board (PCB) that acts as the appliance's brain, controlling all functions, sensors, and user inputs. Also called the main board or motherboard.

Thermistor

A temperature-sensing resistor used in appliances to monitor water, air, or component temperatures. Resistance changes with temperature, allowing the control board to read values.

Drain Pump

A small electric pump in washers and dishwashers that removes water from the tub/sump. Common failure point — often clogged by debris, coins, or lint.

Heating Element

A resistive coil that converts electricity into heat. Found in dryers, ovens, dishwashers, and water heaters. They can burn out, short, or develop open circuits.

Inverter Board

A circuit board that converts DC power to variable-frequency AC to control compressor speed in modern refrigerators and AC units. Enables energy-efficient variable-speed operation.

Door Latch Assembly

The mechanical and electrical mechanism that locks the door during operation (especially in washers and ovens). Includes a switch that signals the control board when the door is properly closed.

Water Inlet Valve

An electrically-controlled valve that opens to allow water into the appliance (washer, dishwasher, ice maker). Solenoid-operated with built-in screens that can clog.

Pressure Switch

A sensor that detects water level in washers and dishwashers by measuring air pressure in a tube connected to the tub. Tells the control board when to stop filling.

Capacitor

An electrical component that stores energy and provides the initial surge to start motors (start capacitor) or maintain efficiency during operation (run capacitor).

Diagnostic Mode

A special test mode built into most modern appliances that runs self-tests on components and displays error codes. Accessed by pressing specific button combinations.

OEM Part

Original Equipment Manufacturer part — the exact replacement part made by or for the appliance manufacturer. More expensive than aftermarket but guaranteed to fit.

Aftermarket Part

A replacement part made by a third-party manufacturer, not the original brand. Often cheaper but quality varies. Check compatibility before purchasing.

Multimeter

A testing tool that measures voltage, resistance (ohms), and continuity. Essential for diagnosing electrical components in appliances without guessing.

Continuity Test

Using a multimeter to check if electricity can flow through a component (wire, switch, element). No continuity = broken/open circuit = component needs replacement.

Ohm Reading

The resistance measurement of a component. Each part has a specified ohm range — readings outside that range indicate failure. Check the service manual for specs.

Hard Reset

Unplugging the appliance for 1-5 minutes to clear the control board's memory and reset error codes. Fixes temporary glitches but won't solve hardware failures.

Service Manual

The technical document with wiring diagrams, error code lists, component locations, and test procedures. Available from the manufacturer, usually by model number.

Wiring Harness

A bundled set of wires and connectors that routes electrical signals between the control board and components. Can develop loose connections, corrosion, or breaks over time.

Tech Sheet

A folded instruction sheet found inside the appliance (often behind the front panel or inside the console) with wiring diagrams and diagnostic procedures.