A canister vacuum cleaner has its own set of repair procedures. Here they are:
Servicing an On/Off Switch: Like the switches on most small appliances, the on/off switch on a canister vacuum cleaner gets a lot of use. Considering the ease of repair and its low replacement cost, this switch is one of the first components to check if a vacuum doesn't turn on or off correctly. To test and replace the switch:
Step 1: Open or remove the canister housing to access the back side of the switch.
Step 2: Use a continuity tester or multitester to ensure that there is an open circuit when the switch is in the OFF position and a closed circuit when the switch is in the ON position.
Step 3: Also check the wiring and terminals to ensure that they are connected properly.
Step 4: If the switch doesn't test correctly, remove it and replace it. Some switches are fastened to the housing with screws, others with clips or friction snaps. A few are riveted in place.
Servicing a Power-Head Wire Connection: An advantage of the canister vacuum is that the part that is pushed and pulled across the floor is lighter than with a single-unit upright vacuum. A disadvantage is that power must be delivered first to the canister, then to the separate power head.
The wire connection between the two units is often a source of problems, even in better-quality canister vacuum cleaners. The reason is that there are four sections to the connecting wire: from canister to hose, from one end of the hose to the other, from one end of the power-head tube to the other, and within the power head itself. The end of each section of wire has a connector. If the connection is not made sufficiently, the power head doesn't operate or operates intermittently.
In most cases, servicing the power-head wire connection simply requires that each connector be checked and tightened as needed. If a specific connector frequently makes a poor connection, you can clean the male and female connections with a small piece of emery paper and a can of compressed air.
Broken wires or worn insulators can sometimes be reconnected and wrapped with electrical tape. However, the wire may be located inside the hose, requiring that the hose be replaced as well.
Servicing a Beater Bar: The beater bar on a canister vacuum cleaner is serviced in almost the same manner as one on an upright unit. Here's how:
Step 1: Remove the clips at each end of the beater bar, and pull it and the drive belt from the power-head case. In many cases, all you have to do is clean the brush and the two ends. Remove any excess pet hair or carpet fibers that get wound into them.
Step 2: If needed, remove the beater bar end cap and flange to remove the brush from the shaft and clean or replace it.
Step 3: Also check the drive belt and replace it if it is worn or damaged.
Step 4: When reinstalling the beater bar, make sure there is sufficient tension on the drive belt to rotate the bar by pulling on the belt. If the belt is loose, adjust it following the instructions in the owner's manual.
Servicing a Motor: The motor for a canister vacuum cleaner is easy to access on most models. To test and replace the motor's brushes:
Step 1: Open the canister's top cover and remove the motor cover to expose the motor itself.
Step 2: Place the probes of a continuity tester or multitester on the two wires that lead to the motor from the on/off switch.
Step 3: Rotate the motor shaft a few revolutions by hand. The motor should test as a closed circuit with some resistance. If an ohmmeter indicates no resistance or infinite resistance, the motor is probably damaged.
Step 4: Check the motor's brushes in the same manner, if they are accessible. Replace the brushes if needed.