Appliance Repair Glossary of Service, Repair and Parts Terms

AERATOR
A device used to infuse air into a liquid. An example is the aerator on the tip of a water faucet. This feature may also be found on some dishwasher faucet adaptors.

AGITATOR
A device that is used to stir or shake up a mixture. Typically used to move clothing through water containing detergent. Sometimes called a GYRATOR.

AIR CONDITIONER
Appliance used to control air temperature and as a byproduct also reduces humidity.

BAKE/BROIL VALVE
An electrically operated valve, that opens and closes by means of a bimetal, to control the flow of gas to a gasoven burner. Sometimes referred to as a oven safety valve.

BIMETAL
A device that is composed of two dissimilar metals bonded together to form a single metal strip. Each metal will expand differently to a change in temperature and cause the single metal strip to bend when heated or cooled. This movement can act as an actuator in various types of switches.

BRITSH THERMAL UNIT (BTU)
The amount of heat energy required to raise the temperature of one pound of water one degree Fahrenheit.

CHILL-PLATE
An evaporator that is in the refrigerator compartment which defrosts each time the thermostat cycles off.

COLD CONTROL
A switch that controls an electric current in response to changing temperature. More properly called a THERMOSTAT.

COLD
The absence of heat. A refrigeration product does not add cold, but merely removes the heat.

COMPRESSOR
An electro-mechanical device used to circulate refrigerant through a refrigeration system for the purpose of transferring heat.

CONDENSATE
Moisture which is recovered from humidity when warm air is cooled.

CONDENSER FAN
An electro-mechanical device used to force air through a condenser to aid in the transfer of heat.

CONDENSER
The part of a refrigeration system where high pressure, heat latent gas is condensed into a liquid by means of heat transfer to the surrounding air.

CYCLE-DEFROST REFRIGERATOR
A style of refrigeration appliance where a portion of the evaporator, usually the chill-plate, defrosts whenever the thermostat switches off.

CYCLE
A series of events which have a tendency to repeat in the same order.

DEFROST TERMINATION THERMOSTAT
A bimetal switch used to open the electric circuit to the defrost heater once a set temperature is reached. The defrost cycle will continue until the timer advances into the cooling cycle, however the heater will no longer be energized. This thermostat will reset to a closed position once a set colder temperature is again reached. May also be called a DEFROST LIMIT SWITCH.

DEFROST TIMER
An electro-mechanical clock device that periodically switches from cooling to defrost to remove the buildup of frost from the evaporator. A possible compressor run time of 6 – 12 hrs. with defrost duration time of 20 – 30 minutes is common.

DEHUMIDIFIER
An appliance designed to extract moisture from the ambient air by means of a refrigeration system. Warm moist air is drawn by a fan across the cold evaporator which causes the water vapor to condense onto the coil and drop into a container. The cooled air is then passed over the condenser where it is warmed before being passed back into the surrounding area.

DOOR SEAL
A resilient or flexible material used between mating surfaces to provide a leak-proof seal. May also be called a DOOR GASKET.

DRAIN PAN
A pan-shaped panel used to collect condensate from the evaporator during a defrost cycle. It is usually located above a condenser coil or atop the compressor. May also be called CONDENSATE PAN.

DRAIN TROUGH
A trough-shaped panel used to funnel defrost condensate, from the evaporator coil, to the drain tube leading eventually to the drain pan.

DRIP PAN/TRAY
A pan-shaped panel used to collect drips, spillage or condensate.

ELECTRO-MECHANICAL
A term used to describe any device that turns electrical power into mechanical work or vise versa. One example is a automobile generator that turns mechanical rotation into electrical power.

ENERGY SAVER SWITCH
REFRIGERATOR-A switch that when activated opens a circuit to an electric cabinet perimeter heater, to turn it off, to save electricity.
AIR CONDITIONER-A switch that when activated allows the thermostat to cycle the fan motor on and off at the same time as it cycles the compressor.

EVAPORATOR
That part of the refrigeration system in which the refrigerant evaporates, absorbing heat from the surrounding area. Sometime mistakenly thought to be that point where the drain pan evaporates the condensate water.

FAUCET ADAPTOR
A male connector that attaches to a water faucet to allow a female connector (dishwasher unicouple) to attach to it. This device sometimes includes an aerator and is often called a TAP ADAPTOR.

FILL VALVE
An electro-mechanical device that opens a valve to allow water to flow. The electric current causes a magnetic field to develop in the solenoid coil which in turn then moves a metallic plunger. The plunger is attached to a diaphragm which opens the valve. May also be called a WATER VALVE or WATER FILL VALVE. If the valve is malfunctioning in any way, replacement solenoid valve products can be sourced on websites like Tameson.com where a wide variety of parts are available.

FILTER DRYER
A device containing screens and absorbent material through which refrigerant gas is passed in order to remove moisture that would be detrimental to other components and the functioning of a refrigeration system.

FILTER
A device containing a porous material or a material itself, through which a liquid or gas is passed in order to separate suspended particulate matter. Common filter materials are activated charcoal, polypropylene and HEPA (high efficiency particulate air [filter]).

FREON
Trade name for a family of synthetic chemical refrigerants manufactured by DuPont. Sometime mistakenly called FreeZone.

FROST-FREE REFRIGERATOR
A type of appliance that automatically defrosts by means of a timing device.

FSP®
An abbreviation for Factory Specification Parts. Used by Whirlpool to differentiate genuine factory replacement parts from those of after market or universal replacement parts.

FUSE
A safety device that protects an electric circuit from excessive current. It consists of or contains a metal filament that melts when current exceeds a specific amperage, thereby opening the circuit.

GASKET
A resilient or flexible material used between mating surfaces to provide a leak-proof seal. May also be called a SEAL.

GYRATE
To revolve around a fixed point or axis.

GYRATOR
See Agitator.

HEAT
A form of energy, the addition of which causes substances to increase in temperature.

IDLER PULLEY
A free wheeling (unpowered) pulley used to put tension on the belt of a dryer or washingmachine.

IGNITOR
A solid state semiconductor that could have been developed through a software similar to Upverter, usually made of Carborundum that produces heat when a current is applied. Typically used to ignite natural gas or propane in heating appliances such as ranges, dryers and water heaters.

INFINITE HEAT SWITCH
A switch that controls the amount of heat generated by an electric range surface burner. It accomplishes this by quickly cycling the voltage on and off to achieve an intermediate range (e.g. at medium it may supply 100% voltage for only 50% of the time it is switched on). It does not act like a rheostat and reduce the voltage, to lessen the heat generated, as sometime mistakenly thought.

LATENT HEAT
The heat energy absorbed in the process of changing the state of a substance (e.g. from solid to liquid, from liquid to gas, or vice versa) without changing the temperature or pressure.

LIMIT SWITCH
A bimetal switch used to open the electric circuit once a set temperature is reached. This thermostat will usually reset to a closed position once a set colder temperature is again reached. May also be called a LIMIT DISC. Also see DEFROST TERMINATION THERMOSTAT.

MANUAL-DEFROST REFRIGERATOR
A type of refrigerator that does not have a mechanical defrosting system and must be defrosted manually. This type of appliance usually has one main outer door with a small door inside, covering the evaporator box.

MICROWAVE OVEN
An appliance that uses microwaves (radio waves in the microwave spectrum) to create friction at the molecular level, to generate heat in food.

MICROWAVE
A high-frequency electromagnetic radio wave, in the spectrum between infrared light and short-wave radio wavelengths.

MOULDING
A piece of plastic used to cover the joint between the inner and outer cabinet of a refrigerator or freezer. May also be called a BREAKER STRIP.

MULLION HEATER
An electric heater mounted inside the mullion to prevent moisture from forming in humid weather.

MULLION
The stationary part of a structure between two doors.

OEM
An abbreviation for Original Equipment Manufacturer. Usually used to differentiate replacement parts supplied by the appliance manufacturer and those of after market or universal replacement parts (e.g. FSP® is used to denote genuine Whirlpool OEM replacement parts).

OVERLOAD PROTECTOR
An electric switch that senses temperature or current (amperage) to stop operation of a unit if a dangerous condition arises.

OZONE
A form of oxygen (O 3) usually obtained by the discharge of electricity in air.

PRESSURE SWITCH
An electric switch activated by air pressure. This device detects air pressure exerted on it through a flexible tube connecting it to part of a water tub. When activated, this switch then opens an electrical circuit stopping further filling of the machine. May also be called a WATER PRESSURE SWITCH, WATER LEVEL CONTROL. The main reason why water pressure drops is because of pipe leakages, learn about epoxy pipe lining here to see how you can avoid this happening. It’s an easy to fix to what can be a big problem if left.

PUMP
A machine or device for moving or compressing fluids or gases.

REFRIGERANT TYPES
R12 (dichlorodifluoromethane) is typically used in some of the best rated refrigerators, freezers and older car air conditioners.
R22 (monochlorodifluoromethane) is used in window air conditioners.
R134a (tetrafluoroethane) is now used in many domestic refrigerators, freezers, dehumidifiers and car air conditioners.

REFRIGERANT
A substance used in a refrigeration system to absorb heat in the evaporator coil, by means of a change of state from liquid to a gas, and to release its heat in the condenser as the substance returns from the gaseous state back into a liquid. Also see Freon.

REFRIGERATOR
An appliance designed to transfer heat from the interior of the cabinet to the exterior.

RELAY
An electro-mechanical switch that diverts the current when the flow is changed or when an external current is applied.

SILFOSS
A silver-alloy solder containing 5-15% silver. It is used to weld copper to copper joints in refrigeration systems and able to withstand high pressures.

SILVER SOLDER
A silver-alloy solder with 35% or higher silver content. Used to withstand high refrigerant pressures in joints made between copper and steel tubing.

SOLENOID
An electro-mechanical device that produces a magnetic field, to move an internal metallic plunger, when power is supplied. When power to the electromagnet is discontinued, the plunger is free again to move by other forces. This plunger can be attached to other devices (levers, seals, etc.) to do mechanical work.

SOLID STATE RELAY
An electronic switch that diverts the current when the flow is changed or when an external current is applied. May also be called a TRIAC.

TAP ADAPTOR
A male connector that attaches to a water faucet to allow a female connector (dishwasher unicouple) to attach to it. This device sometimes includes an aerator and is more properly called a dishwasher FAUCET ADAPTOR.

Therm-O-Disc, Inc.
Therm-O-Disc is a manufacturer of temperature sensors, temperature controls and electrical switches for the appliance, HVAC, automotive and commercial industries and is a subsidiary of Emerson Electric Co. Probably most notably associated with their bimetal disc thermostats.

THERMODISC
A mechanical electric switch that is responsive to changing temperature by means of a bimetal actuator.

THERMOSTAT
A switch that controls an electric current or the flow of a liquid or gas in response to changing temperature.

TIMER
A mechanism used to control the on and off times of an electric circuit. Also see DEFROST TIMER.

TRIAC
An electronic relay that diverts the current when the flow is changed or when an external current is applied.

UNICOUPLE
Device used to attach the fill and drain hose of a portable dishwasher or washing machine to a faucet (tap) adaptor mounted on a sink faucet – Unicoupler

WATER LEVEL CONTROL
An electric switch activated by air pressure. This device detects air pressure exerted on it through a flexible tube connecting it to part of a water tub. When activated, this switch then opens an electrical circuit stopping further filling of the machine. May also be called a PRESSURE SWITCH.

WATER VALVE
An electro-mechanical device that opens a valve to allow water to flow. The electric current causes a magnetic field to develop, in the solenoid coil, which then moves a metallic plunger. The plunger in turn opens the valve. May also be called a FILL VALVE.

YODER HEATER
A heater (either electric or part of a refrigeration system’s condenser tubing) typically mounted around the front perimeter of a refrigerator cabinet to keep it warm and prevent condensation from forming.