# How to Unclog a Kitchen Drain

Source: https://cantleyvidanjoraltyapi.com/en/unclog-kitchen-drain/

> A blocked kitchen drain is usually caused by grease and food scraps that have hardened in the trap and the wall pipe. Bail the water out of the sink, soften the grease with hot tap water and washing-up liquid, and use a plunger, blocking the other bowl if you have a double sink. If the flow does not return, take the trap off over a washing-up bowl and clean it, then run a drain snake into the wall pipe.

Most people searching for how to unclog a kitchen drain are facing the same sight: the kitchen sink is blocked, the water will not go down and there is a greasy film on the surface. Unlike a bathroom sink, the main cause of a kitchen blockage is not hair but grease, which flows while hot and sets in the pipe once it cools. Starch from rice and pasta water, coffee grounds and small food scraps stick to this grease and slowly, almost unnoticed, narrow the pipe starting from the trap.

The kitchen drain also carries the dishwasher's outlet, so a blockage is sometimes noticed at the machine first. In this guide we start with methods you can try without taking anything apart, then cover cleaning the trap and the kitchen drain pipe, and finally the problems that come from the building's shared kitchen stack. We have also said clearly at which point you should stop trying at home, because one wrong step can turn a small grease blockage into a pool of dirty water spreading under the worktop.

## Why does a kitchen drain block?

A kitchen drain blocks because grease that flows with hot water sets in the colder part of the pipe, and food scraps and starch stick to it.

### Frying and cooking oil

Oil left in the pan is liquid while hot, but after travelling a short way down the pipe it cools and turns into a layer with a soap-like consistency. The thin layer added every day gradually narrows the inner diameter of the pipe quite noticeably.

### Starch and dough residue

Water from boiling rice, pasta and potatoes leaves a sticky sludge at the bottom of the pipe. When this sludge mixes with grease, it forms a rubbery plug that water does not easily dissolve.

### Coffee grounds and tea leaves

Grounds and tea leaves do not dissolve in water. They get heavier and settle in the bend of the trap. Combined with the grease layer, they turn into a filling that sets as hard as sand.

### Corrugated waste hose

The flexible, folding corrugated pipe often used under the worktop has a ribbed interior. Every ridge catches grease and crumbs, so it blocks much faster than straight-pipe connections and causes smells.

### Dishwasher outlet

The machine pushes greasy, crumb-filled water into the trap at a high flow rate. If the machine's filter is not cleaned or the outlet hose is kinked, both the machine and the sink drain are affected.

### The building's kitchen stack

In multi-storey buildings, the kitchens are connected to the same vertical pipe. Over the years, grease that builds up in the bends of this stack causes water to come back up in the sinks on the lower floors.

## Signs that show where the blockage is

What you see in the kitchen largely shows whether the problem is in your own trap or in the line inside the wall.

### Water stands in only one bowl

If only one side of a double sink fills, the blockage is most likely in the strainer of that bowl or in the short branch that connects to the trap. This is the easiest case to fix at home.

### Both bowls fill at once

If both bowls hold water, the blockage is in the shared part of the trap or in the pipe entering the wall. A plunger and cleaning the trap often work here.

### The dishwasher's water comes up in the sink

If dirty water rises from the bottom of the sink while the dishwasher empties, it means the machine's outlet and the sink are connected to the same blocked point.

### A smell rises from the drain opening

A smell from a kitchen drain most often comes from greasy residue sitting in the trap and the corrugated pipe. If the smell continues even after the trap has been cleaned, the source is the line or the stack.

### Your sink fills when the flat above uses water

If water rises in your sink even though you have not turned on the tap, there is a narrowing in the stack. This is not a problem you can fix from your own kitchen.

## How to clear a kitchen drain pipe

A kitchen drain pipe is cleared with methods that first soften the grease and then push it through mechanically. Work through them in order, and if you have poured a chemical down the drain, do not move on to these steps at all.

### 1. Bail out the water and clean the strainer

When the sink is full to the brim and the water is not draining at all, before every other method.

1. Use a jug or a bowl to transfer the water from the sink into a bucket, leaving a small amount at the bottom.
2. Lift out the strainer basket and remove the crumbs and grease lumps underneath with a gloved hand.
3. Clean around the ring the strainer sits in with an old brush and washing-up liquid.
4. Put the strainer back and run a small amount of water to see whether the flow has changed.

> The water in the sink is greasy and cold. Take care not to splash it onto the worktop or into the cupboard when bailing. If a chemical has been mixed into the water before, do not touch it with bare hands.

### 2. Dissolve the grease with hot water and washing-up liquid

When the water drains slowly and you think the blockage is caused by grease.

1. Squeeze plenty of washing-up liquid into the drain. The liquid binds the grease and makes it easier to break down.
2. Slowly run the hottest water you can get from the tap, or pour in a pan of warmed water a little at a time.
3. Wait for a while and repeat the process two or three times.
4. Then leave the hot tap running for a few minutes to carry the loosened grease further down the line.

> Boiling water softens the PVC trap and the corrugated pipe and damages the seals, so do not use it. The grease only loosens and can set again further down the pipe, so finish the process with plenty of hot water.

### 3. Use a plunger on a double sink

When water stands in both bowls, does not move with hot water and no chemical has been poured down the drain.

1. Block the drain of the other bowl firmly with a plug or a wet cloth. If it stays open, the pressure escapes through it.
2. If the dishwasher's outlet hose is connected to the trap, ask someone to hold the hose bent shut so the dirty water is not pushed back into the machine.
3. Leave enough water in the sink to cover the rubber cup of the plunger, seat the plunger over the drain and work it with firm back and forth strokes.
4. Pull the plunger away suddenly. If the water drains quickly, flush the line with hot tap water for a while.

> Because a kitchen blockage is greasy, the plunger can splash dirty water upwards, so keep your face away from the drain. Do not use a plunger if a chemical drain opener has been poured down the drain.

### 4. Take off the trap and clean the corrugated pipe

When the plunger has not worked or the smell comes straight from under the worktop.

1. Empty the space under the sink, put a wide washing-up bowl under the trap and lay newspaper around it.
2. Loosen the trap nuts by hand, along with the dishwasher hose connection if there is one, and take the parts into the bowl.
3. Scrub the trap chamber, the corrugated pipe and the outlet the machine connects to in hot water with washing-up liquid, using a brush.
4. Check the seals, refit the parts in order and tighten the nuts by hand.
5. Run the hot water and hold dry paper against the joints to check for leaks.

> Do not tighten the nuts with a tool, as the plastic thread strips easily. If you are fitting a new kitchen drain pipe, make sure the trap sits upright, give the pipe a slight fall towards the wall opening and see that every seal sits flat. Replacing a corrugated pipe that has held a lot of grease with a straight PVC piece lasts longer.

### 5. Run a drain snake into the wall pipe

When the trap is clean but water still comes back from the wall opening.

1. With the trap removed, put a washing-up bowl under the pipe coming out of the wall.
2. Push a flexible hand-turned drain snake into the pipe and feed it forward, turning it without forcing it at the bends.
3. When the snake reaches the grease plug, break the plug up with back and forth movements, then pull the snake out and clean its tip.
4. Refit the trap and run plenty of hot water to send the loosened grease further down the line.

> A hand snake only reaches a few metres and cannot get to a blockage in the stack. With hard grease plugs the snake makes a hole but leaves the grease on the pipe wall, so the blockage can return quickly.

### 6. Check the dishwasher drain

When the dishwasher drain is blocked and water stays at the bottom of the machine.

1. Switch the machine off, unplug it and take out the lower basket.
2. Twist out the filter at the base of the machine and brush it under running water.
3. Clear the crumbs and any pieces of glass from the housing the filter sits in, wearing gloves.
4. Check that the outlet hose is not kinked under the worktop and that the opening where it connects to the trap is clear.
5. Refit the filter and run an empty short programme to see whether the machine empties its water.

> If water stays in the machine even though the filter is clean and the hose is straight, the problem is either the machine's pump or the sink trap. If the sink is also draining slowly, clean the trap first.

## Habits that damage a kitchen drain

### Pouring frying oil down the sink

Hot oil seems to pass through the drain, but it sets once it cools in the pipe. Let the oil cool, collect it in a bottle with a lid and take it to a used-oil collection point.

### Trying to melt grease with boiling water

Boiling water melts grease for a short while, but it softens the PVC pipe and the corrugated hose and makes the connections leak. The melted grease also sets again in the cold pipe further along.

### Plunging on top of a chemical opener

Drain openers react with grease and heat up. Plunging or taking the trap off can splash this hot, burning water onto you. Always tell the technician which product you used.

### Mixing cleaning products

Using bleach and a drain opener, or two different openers, one after the other can release dangerous gas. The risk is even greater in a kitchen with a small window.

### Washing coffee grounds and food scraps down the drain

Grounds, rice and pasta scraps seem to flow away with the water but settle in the trap. Scrape plates into the bin first, then wash them.

## When to get help if your kitchen drain will not clear

If the kitchen drain stays blocked after hot water, a plunger, cleaning the trap and a hand snake, it is time to get help. The same goes if the blockage returns every few weeks, if water still comes back from the wall opening with the trap removed, or if a chemical has been poured down the drain. These signs show that the grease has built up in the horizontal line or the stack, well beyond the trap, and a hand snake cannot reach that far.

In flats, kitchen drain blockages are especially common on the ground and lower floors. When water from the upper floors cannot get past the narrowing in the stack, it comes back up through the sink at the lowest point, and however much you clean your own trap, the problem continues. In such a case, tell the building management and reach the Cantley team on 0212 923 66 85 or via WhatsApp. The team comes to the address, inspects the stack and the line, explains what it sees to you and only then starts work.

## How do we clear a kitchen line without breaking anything?

To clear a kitchen line without breaking anything, we first use a camera to see where the grease has built up and how thick it is. With the trap removed, the camera is fed in from the wall opening and shows on the screen whether the blockage is right behind the sink or at a bend in the stack. We share the footage with you too, and we decide which tool to use by looking at it.

Fresh, soft blockages are cleared with a motorised drain snake. Grease that has hardened like stone over time is scraped off the pipe wall with a robotic machine, and then the line is flushed from start to finish with high-pressure water jetting. Because the inner surface of the pipe is cleaned instead of just making a hole, the chance of the blockage returning quickly is reduced. When the work is finished, the flow is tested together with you, the final state is shown by camera if needed, and no tile or wall is broken in your kitchen.

## Ways to keep your kitchen drain pipe clean

- Do not pour pan grease into the sink. Let it cool, collect it in a bottle and take it to a used-oil collection point.
- Wipe greasy pans and pots with kitchen paper before washing them.
- Use a fine-mesh strainer over the drain opening and empty it into the bin after every wash-up.
- After pouring away rice and pasta water, run the hot tap for a while.
- Once a week, run washing-up liquid and hot tap water down the drain to loosen the thin layer of grease.
- Take out and wash the dishwasher filter regularly.
- If you have a corrugated pipe under the worktop, consider replacing it with a straight PVC trap connection.
- Freshen the trap once a month with baking soda and vinegar. This mixture helps with smell but does not clear a blockage.

## Frequently asked questions

### My kitchen sink is blocked and the water will not go down. What should I do?

If your kitchen sink is blocked and the water will not go down, first bail the water into a bucket with a bowl and clean the strainer. Then soften the grease with washing-up liquid and hot tap water, and use a plunger, blocking the other bowl if you have a double sink. If that does not work, take the trap off and clean it. If water still comes back from the wall opening with the trap removed, the blockage is further along the line.

### Why does a kitchen drain smell?

A kitchen drain mostly smells because of rotting grease and food scraps in the trap, the corrugated pipe and the dishwasher filter. Cleaning these parts removes most of the smell. If a sewer smell continues after cleaning, the trap seal may be leaking, the water in the trap may be getting drawn out, or the ventilation of the stack may be inadequate.

### My dishwasher drain is blocked. How do I clear it?

When the dishwasher drain is blocked, first unplug the machine, take out the filter at the base and wash it. Then check that the outlet hose is not kinked and that the opening where it connects to the trap is clear. If the sink is also draining slowly, the problem is most likely in the trap, and cleaning the trap will also ease the machine's drainage. Do not assume the machine is faulty before doing these checks.

### Can I pour boiling water down a kitchen drain?

Pouring boiling water down a kitchen drain is not recommended. Boiling water softens the PVC trap, the corrugated pipe and the seals, and causes leaks. The hottest water from the tap and washing-up liquid are enough to loosen grease. Afterwards, leave the water running for a while to carry the loosened grease further down the line.

### Will baking soda and vinegar unclog a kitchen drain?

Baking soda and vinegar only remove a light grease film and smell. They will not clear a completely blocked kitchen drain. The fizzing loosens soft dirt, but its effect on hardened grease, coffee grounds or a starch plug is limited. It is better to use this mixture for monthly maintenance than to unblock a drain.

### Is a chemical drain opener safe in a kitchen drain?

Chemical drain openers are not safe in a kitchen drain unless used carefully. They react with grease and heat up, can damage old or thin PVC pipe, and burn the skin if they splash. If the product does not work, the drain stays full of burning liquid, and both plunging and taking the trap off become dangerous. If you have used one, always tell the technician.

### Why does the kitchen drain overflow on the lower floors of a building?

On the lower floors, the kitchen drain overflows because grease built up in the shared stack stops water from the upper floors getting through, and the water comes back up through the sink at the lowest point. Cleaning your own trap does not solve this. You need to tell the building management and have the stack inspected by camera and flushed with high-pressure water.

## If water still comes back in your kitchen drain

Call 0212 923 66 85 or message us on WhatsApp. The Cantley team comes to all 39 districts of Istanbul 24/7, finds the grease blockage with a camera and cleans the line without breaking anything in your kitchen.

Phone: 0212 923 66 85 (tel:+902129236685)  
WhatsApp: https://wa.me/905315687185