When clothes dryers were introduced in the 1920s, they were simply cabinets filled with hot air in which clothes were hung on racks to dry. Their large size made them impractical for home use.
The spin dryer was a German invention. But American manufacturers were quick to adopt the technology. The combination washer-and-dryer, which did both jobs in the same unit, was introduced after World War II. But it had so many problems that people refused to buy it.Manufacturers found it easier to make and sell separate washers and dryers.
The dryer is an uncomplicated device, powered by an electric motor, that tumbles clothes in a steady flow of hot air. A fan pulls in air and circulates it past a heating unit, either electric or gas, into a rotating drum holding the clothes. The hot air absorbs the moisture from the clothes and is forced through a lint filter to the outside.
For the dryer to function satisfactorily, it has to be level and properly vented. Usually that is done on installation. But it is not uncommon for vibrations to upset the level, and if the unit has been moved it may need to be leveled again.
If the dryer is unlevel - that can easily be checked with a carpenter's level - it can be adjusted by turning either or both of the leveling legs under the front corners.
The rigid-tubing vent ducts and elbows should be at least 4 inches in diameter. There should be a minimum of flexible foil or plastic, they can trap lint and clog the vent. The duct should be as straight and as short as possible.
Most manufacturers recommend a maximum of 16 feet. All joints should be sealed with duct tape or clamps, not sheet-metal screws. The bottom of the exhaust vent should be at least 12 inches from the ground. If the dryer is in a small utility room, it is a good idea to install a vent in the door to allow fresh air into the room.
Disassemble the ducts yearly to remove lint. Lint buildup can stop airflow, reduce the efficiency and create a fire hazard. Besides cleaning the ducts, remember to remove and clean the filter with every load.
The motor rotates the drum by a drive belt. A worn belt will slip frequently, causing intermittent rotation. If the belt breaks, the drum will not turn. In either case the belt should be replaced. Remember to switch off the main power before maintenance.
Dryers have two basic belt configurations. The most common uses a single belt wrapped around the drum and motor pulley. The belt also winds around a spring-mounted idler-wheel assembly. The idler wheel maintains the proper belt tension between the motor and the drum. To change the drive belt you will have to remove the front panels.
The second configuration uses two drive belts. One passes around the motor pulley that drives a blower and an idler pulley. The second connects the idler pulley to the drum. To service that system you will have to remove the rear access panel.
For dryers with two-belt systems, open the rear access panel yearly and lubricate the blower bearings with nondetergent SAE-30 motor oil. Most dryers have a lubrication wick that can be saturated with the oil. That will keep the bearings lubricated for at least a year.
Check the configuration by removing the rear access panel, which is easier than removing the front panels. If there are no belts in the rear, remove the front panels.
You will probably have to lift up the cabinet top to free the front panel. The top may be secured with retaining screws at the rear corners or near the lint trap.
Remove the old belt and fit an identical replacement around the drum, motor and idler pulleys. Vacuum the inside of the cabinet to remove lint and dust.