What happens to grease after it goes down the sink
Fats, oils and grease leave the sink warm and liquid, then cool as they travel through the drain. They stick to the pipe walls and bind with food particles and soap residue into a waxy layer. Each layer narrows the pipe a little more until a clump of food or a burst of dishwasher water is enough to stop the flow.
The kitchen branch line often runs a long way horizontally before joining the main, sometimes under a slab in single-story Fullerton homes. Long, flat runs give grease more time to cool and settle. That is why the kitchen line is so often the first drain in a house to cause repeat trouble.
Kitchen line quick facts
- Common cause
- Grease, food solids and soap residue coating the pipe wall
- Typical symptom
- Sink drains slowly, then backs up when the dishwasher runs
- Why snaking fades
- The cable opens a channel but leaves most of the coating
- What jetting adds
- Scours the full circumference and flushes the residue out
- Access needed
- A cleanout on the kitchen line, or another suitable entry point
How a kitchen line is usually jetted
- Find access.The plumber looks for a cleanout on the kitchen branch, often under the sink, on an outside wall or in the yard. The trap and sink tailpiece are usually too small for a jetter hose.
- Check the line.A camera or test run helps confirm grease is the cause and the pipe is sound.
- Jet toward the main.The hose is run through the branch with a nozzle sized for the pipe, pulling grease off the walls and flushing it downstream.
- Flush and test.Hot water is run through the line, and the sink and dishwasher are tested under load.
- Confirm.If a camera was used, a second pass shows how much of the coating was removed.
Habits that slow grease buildup afterward
- Wipe greasy pans with a paper towel before washing them.
- Pour cooled cooking fat into a container for the trash, not the sink.
- Use a sink strainer and empty it into the trash.
- Run the garbage disposal with plenty of cold water and avoid sending fibrous or starchy scraps down it.
- Do not rely on hot water alone to carry grease away; it cools further down the line.
Questions to ask about a kitchen line
- Where is the access point for my kitchen line, and is it suitable for a jetter?
- Is the clog in the kitchen branch or further down in the main?
- Did you see grease, scale, a sag or something else?
- How long should I expect the line to stay clear with good habits?
Common questions
Why does my kitchen sink back up when the dishwasher runs?
The dishwasher sends a large volume of water into a line that is already narrowed. If the water cannot pass fast enough, it rises in the sink. Grease buildup in the kitchen branch is a common cause.
Can enzyme cleaners keep grease out of the line?
Some homeowners use them as maintenance. They are slow-acting and are not a substitute for clearing a line that is already badly coated. Ask your plumber whether one makes sense for your situation.
My kitchen line has no cleanout. Can it still be jetted?
Sometimes. A plumber may use another access point or recommend adding a cleanout. Ask what they suggest and whether a permit applies; check with the City of Fullerton.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.