Pumping and cleaning are one job on the grease device: remove everything inside, scrape the walls, leave it empty. Jetting is a different job on the pipes: high-pressure water scrubs grease off the drain and sewer lines downstream. Neither replaces the other.
Pumping and cleaning: the grease device
Pumping empties the trap or interceptor. Cleaning is the second half of the same visit. In Phoenix's FOG manual the requirement is that the device be "completely pumped out and cleaned," with the grease mat, liquids, sludge and wall scrapings removed and the tank left empty. A pumper who only sucks off the top has not met that.
This service is regulated. The city sets how often it happens, the person doing it must be a licensed pumper, and you keep the record for three years.
Jetting: the pipes
Jetting sends pressurized water through a nozzle down a drain or sewer line to scrub the inside of the pipe. It targets what the device did not catch or what built up before the device was installed or working properly. Phoenix's manual mentions "routine jetting of the sewer lines" as a cost that good kitchen habits reduce. Scottsdale explains why grease travels: hot water and soap wash it out of sight, but it cools and solidifies further down the pipe.
No city rule schedules jetting the way it schedules pumping. It is a maintenance decision, usually made after a slow drain or a backup.
Why one does not replace the other
- Pumped but never jetted: the trap is clean, yet grease can still coat the pipes between your kitchen and the tank, and beyond it.
- Jetted but never pumped: the pipe is clear today, while a full trap sends fresh grease downstream tomorrow. Chandler says that if grease is seen leaving the device, the cleaning frequency must increase.
What to do
Start with the device on its city schedule. Add jetting when floor sinks drain slowly, when the camera shows a coating, or after a backup. Our hydro jetting page covers the pipe side, and what happens during a grease trap cleaning covers the pump-out. If the same sink keeps backing up, read why a commercial kitchen drain keeps overflowing.
Backed up right now? Start with what to do when a grease trap backs up into the floor sinks. Grease still coating the line after regular pump-outs points to one of five causes past the interceptor.