Drain Cleaner: Auger not Turning

The armature is the power-producing unit of an electric motor, which is located inside of a magnetic field. The armature has a commutator on its shaft, with brushes riding on it, supplying power to the armature.

To inspect the armature for damage, and to test, start by pulling the cable out of the drum and remove all of the screws on the outside of the drum. Separate the two halves of the drum. Remove the crown nut, washer, and the rear drum. Remove the screws on the gear case. You may have to gently tap the gear case off, or in some cases, use a puller. Separate the two halves of the handle then locate the brush holders and remove.

Remove the armature from the housing and clean it thoroughly with thinner and dry completely. Check the commutator for missing bars. If any are missing, you will need to replace the armature. Next, inspect the commutator for burn marks. You can clean the commutator lightly with a file or sandpaper.

Stand the commutator up on a bench. With an ohmmeter, attach the two ends to both sides of the commutator. This allows you to measure the resistance of the windings. As you move it around the commutator, the reading number is not important. You are looking for a consistent reading, indicating all the windings are good. If it varies radically, reading a zero or open circuit, then the armature is bad. Another test is reading. If the ohm reads zero, or open circuit, then that indicates a bad armature. A final one you can do is a bar to ground test, which is done by placing one end of the ohmmeter to the tip of the shaft on the armature and the other to the commutator.

If the armature is bad, install a new one. Install the armature in the housing, reinstall the brushes and then reattach the two halves of the housing. Reattach the gear case, rear drum, crown nut (with washer), the front part of the drum and tighten. Reconnect the cable by pulling up on the power grip shield, inserting the cable in the drum. Use an up-and-down motion until the cable begins to bend and starts to install in the drum. Install the entire cable with the grip shield in the “up” position.

A field coil is an electromagnet, used to generate a magnetic field in an electro-magnetic machine. To inspect and test the field, start by removing the cable from the drum. You can do this by simply pulling it out. Next, clear off all screws along the perimeter of the drum and separate the front of the drum from the rear. Remove the crown nut, washer and the rear drum from the unit. Remove the screws on the gear case. You may have to gently tap the gear case off, or in some cases, use a puller to get the gear case off. Separate the two halves of the handle and locate the brush holders and remove. Remove the armature from the housing. Clear off the screws that are securing the field to the housing and take out the field.

To test the field, place one end of the multimeter (set to ohms) on the inlet wire side, and the other on the outlet wire side. Do this procedure for all the field coils on the field. The readings should be the same – zero or close to. If they are different, or the multimeter reads infinity, then replace the field.

Once replaced, reinstall the armature into the housing, as well as the brushes, and reattach the two halves of the housing. Reinstall the gear case, rear drum, crown nut (with washer), the front part of the drum and tighten. Reconnect the cable by pulling up on the power grip shield, inserting the cable in the drum. Use an up-and-down motion until the cable begins to bend and starts to install in the drum. Install the entire cable with the grip shield in the “up” position.

A gear is a rotating machine part that has cut teeth, which meshes with another toothed part to transmit torque. If one, or more, of the gears becomes stripped, or has missing teeth, it will not be able to make proper contact with the other gears. This will result in the auger not rotating. If there is a problem with the gears, you will usually hear a noise, such as a grinding sound.

First, you must remove the cable from the drum by simply pulling it out. Take out all of the screws along the drum’s perimeter and separate the two halves of the drum. Remove the crown nut, washer and the rear drum. Take out the screws on the gear case. You may have to gently tap the gear case off, or use a puller to remove. Install the new case and reinstall the rear drum, crown nut (with washer), and then reattach the front portion of the drum. Reconnect the cable by pulling up on the power grip shield, inserting the cable into the drum. Use an up-and-down motion until the cable begins to bend and installs into the drum. Install the entire cable with the grip shield in the “up” position.

The switch allows you to control the flow of electricity to the electric motor. If the motor is not receiving power when you pull the switch, it may require a new switch. To inspect and test the switch, separate the two halves of the housing on the handle. Locate the switch and disconnect any wires at the switch as well as any fasteners that hold the switch to the housing.

With the switch now removed, inspect it for burn marks. If you notice any, replace the switch. If the switch looks good, you can test it by attaching a multimeter set to an ohmmeter and then to the connection points on the switch. While the switch is in the “on” position, the ohmmeter should read zero, or close to zero. In the “off” position, it should read infinity. If your switch is reading infinity in both positions, the switch will need to be replaced. Install the new switch and fasten it down, reattaching any wires. Rejoin the two halves of the handle back together.

The brushes supply the motor with electrical power by riding on the commutator. As the brushes wear down, it can impact their ability to supply power to the armature via the commutator. If the brushes have a lot of dirt and grime build up, it can also disrupt the flow of electricity. To inspect the condition of the brushes, separate the two halves of the handle on the drain cleaner. With the motor exposed, locate the brush caps, or holders, at the rear of the motor and remove them. Inspect the brushes. If the brushes are less than 1/8 of an inch from the wire, they are worn out and require replacement. If they have a heavy build up of dirt, you can clean and reinstall them. Install the brushes back in the caps, and then back in the motor housing. Reattach the two halves of the unit back together.