Garbage disposal runs but water backs up into the sink; grinding seems normal but sink drains very slowly or not at all.

Safety first: Turn off power to the disposal at the switch and breaker. Do not run the disposal while the drain is blocked.

• Step 1 – Check for simple sink blockage: Remove standing water with a cup. Do not use chemical drain cleaners in a disposal-equipped sink.
• Step 2 – Inspect discharge elbow: Loosen the slip nut on the disposal discharge elbow and remove the elbow. Check for packed food debris and clean thoroughly.
• Step 3 – Verify dishwasher knockout: If a dishwasher is connected, remove the hose and confirm the metal/plastic knockout plug inside the disposal inlet has been removed. If still present, carefully knock it out with a screwdriver and hammer (with power disconnected), then remove the loose piece from inside the disposal.
• Step 4 – Clean P-trap and drain line: Place a bucket under the P-trap. Remove the trap and horizontal drain arm. Clear any sludge or food buildup and reassemble.
• Step 5 – Test for proper drainage: Restore power, run cold water, and briefly operate the disposal. Confirm that water flows freely down the drain.
• Step 6 – If drain remains slow: There may be a deeper clog in the wall drain. Use a drain snake or contact a plumber; this is beyond the disposal itself.