Solve It! Getting the kitchen sink to drain reliably

 

How To Solve It by G Polya

I am starting a new "Solve It!" series of blog posts.

This book came highly recommended to me many years ago and sadly I never gave it enough of my time. If I can still find it in my shed, I will give it another attempt.

It thought of the book because I was reminded of it while trying to come up with a title for this series of blog posts.

The book talks about problem solving strategies in mathematics. I won't discuss math here, but the idea is the same. You have to be a deep thinker to solve everyday problems.

Contrary to Nobel Prize winners and such, my fascination in life has been with solving the common problems that plague us. The problems are common but the solutions often seem to evade us.

This blog series will provide a few examples.

Getting the kitchen sink to drain reliably

If this sounds like a trivial problem to you, it is likely because you don't cook much or you just call the plumber. Here are the key elements to consider.

The word plumbing should be viewed as almost analogous to the PVC pipes that form most of the inlet and outlet of water to and from your bathrooms, kitchen, and appliances (washer, dishwasher).

The plumbing system is charged with bringing water in from your city water supply and exiting sewage out to your city sewage system.

The best way to learn about how to solve plumbing problems is to either work in a restaurant kitchen and pay close attention to the sink area or do a lot of cooking and dishwashing at home WITHOUT HELP.

1. Water pressure and flow (obvious)

The water in your kitchen sink has to be able to flow down the drain and into the plumbing system. Study the plumbing system under your kitchen sink and see where it goes. Usually the kitchen pipes are kept separate from the bathroom pipes. You will soon understand why. When the flow of water is obstructed water will start to build up in the sink and it will either drain very slowly or in extreme cases not at all. 

If you're not careful water will overflow the sink and onto your kitchen floor. This is why kitchen and bathroom floors should ideally be tiled. So that water doesn't seep into the wood and cause permanent damage.

There are multiple places to look for blockages. This is where keen observation is critical. 

Firstly, there's a strainer basket in the sink that can get sucked into the sink due to negative air pressure (aka suction; more on that later). If the strainer basket seems stuck in the sink, you will need to apply gentle force to pull it out just enough to see a few air bubbles rise through the water in the sink. You don't want to outright pull the strainer basket out because then you're letting in gunk from the sink into the plumbing, which a huge no-no (see section 5). Air coming out of the pipes creates a vacuum that sucks water in and assists with water flow going back down the drain. This is an every minute thing. If you do the dishes you know this.

Secondly, there's usually a way to remove the strainer (the housing that envelopes the strainer basket) in the sink that is immediately under the strainer basket. The strainer ships with the sink and attaches to the PVC pipes under the sink. The strainer often traps food particles and can itself become a source of blockages. Removing and reattaching the strainer is not a trivial task. And if you mess up you will end up with a leak under your sink. Plumbing work comes with the risk of water damage and is not for the faint of heart.

Thirdly, if #1 and #2 don't do the trick, you can try to snake the drain. You need to look for an entry point into the plumbing, usually under the sink or in your basement via what are known as cleanouts. 

The first attempt should be to snake from the top, starting from somewhere under the sink where the strainer or air vent (see section 2) connect to the plumbing. Operating a snake is an art that I won't get into here. However, note that most of the blockages are at the bends in the pipes. So, ideally cleanouts should strategically be located near those bends.

If going in with your snake from the top doesn't do the trick, your next option is to find the cleanouts (named for a reason) usually in the basement. When opening the cleanouts, open them very slowly and carefully position a bucket underneath to capture most of the water that's going to leak out. It's best to wear goggles, raincoats and such because of the risk that sewage will spill on to you at some point or another. And now you understand why the bathroom plumbing is kept separate from the kitchen plumbing.

2. Air pressure and flow (not obvious)

Sewage is the technical name for what goes down the plumbing pipes. Most of the sewage flows out of your house and into the city's sewage system. But over time, some sewage (mostly grease mixed with food particles) sticks to the sides of your PVC pipes and rots. The chemical reactions in rotting sewage result in the release of gases. Ventilation pipes (not to be confused with drainage pipes) release these gases up into the air. These vents either go up through your roof (in the case of bathrooms and regular kitchen sinks) or though under-the-sink air vents (in the case of island kitchen sinks).

If you decide to use the air vent under the kitchen sink as your entry point with the snake, I would suggest marking up exactly how tightly the air vent was screwed in before you remove it. I have found that after snaking, if the vent isn't screwed in just right the air won't vent properly and the sink will overflow. When you snake the pipe and water finally gets unclogged and moves down the pipe, it creates a vacuum wherein air rushes in to fill that space. When you open the kitchen sink faucet again after snaking, water is rushing into the pipes and displacing the air from the pipes. That air needs somewhere to go and I believe it escapes from the vent. So after snaking, the air vent needs to be screwed in just right to let the air out and allow the water to flow down the pipes. You might even have to fiddle with the vent a bit (unscrewing and screwing in tiny steps) until the air pressure to water pressure balance is restored and water starts flowing smoothly through the pipes with the blockage now removed.

Final note. I don't recommend using chemicals like Drano (see more below) or plungers. Plungers can cause damage to the fittings that connect the various parts of the plumbing system. If you must use a plunger, use it very gently to get the water flowing. As an aside, using the plunger in the toilet is okay because you're not dealing with delicate plumbing fittings in that case.

3. Grease

If you don't know how to handle kitchen grease, it might be a good idea to work in a restaurant kitchen and pay close attention to how they handle grease. I don't know what most people who cook at home do, but kitchen grease (e.g. what's left over when you cook bacon) should NEVER EVER be dumped into the kitchen sink. Grease that inevitably goes down the drain is what clogs up the drains as it solidifies in colder areas of the pipes and around the bends. I use empty pasta sauce jars to collect as much of the grease as possible before washing utensils. After pouring out the grease, take a rag or paper towel and wipe off as much of the remaining grease as possible from the surface of your utensil prior to washing. Grease is the main ingredient of blockages in kitchen sink pipes. So you want to minimize the amount of grease that goes down the drain.

Once I have collected a box full of grease jars, I take them to the hazardous materials collection point that is organized once a month in my city. When I tell them I am dropping off kitchen grease or used cooking oil, they usually look at each other quizzically and finally accept it. Goes to show how few people cook. And of those who do cook, how few are responsibly disposing the used cooking oil or kitchen grease.

To tackle the bits of grease that does get into your plumbing despite your best efforts, run hot water through the sink for several minutes once a week. the hot water will melt the grease and push it through the pipes and into the city sewage system.

If hot water alone doesn't do it, put a few spoons of baking soda into the strainer and pour vinegar until all the baking soda mixes with the vinegar. The fizzing and air bubbles (carbon dioxide) create a mechanical action or agitation that dislodges clogs. Additionally, the mixture of baking soda and vinegar has grease-cutting properties. Vinegar is acidic and helps dissolve fatty acids in grease clogs, while baking soda is alkaline and helps break down oils and fats through saponification (turning fats into soap-like substances). Unlike harsh chemical drain cleaners, this approach won't damage most plumbing materials, making it safer for regular use. As a bonus, baking soda helps neutralize odors that often come from food waste in drains.

4. Water Jetting

This is the nuclear option. If all of the above don't work, or you just want to do an annual clean up of the plumbing (a good idea), you can use a water jetting attachment with your pressure washer. Ideally also use a waterproof endoscope camera with a light so that you can examine the blockages and confirm that you've cleared them out via the water jetting.

5. Discipline 

If you don't follow the discipline described above, you will run into blockages that are harder and harder to resolve. Just like a discipline of good diet and exercise is needed to prevent your blood circulation system from blocking, you need to follow a discipline to avoid having to call a plumber or resolve plumbing issues yourself.

Good luck!

Next in this series.

Getting the slide numbers on your PowerPoint slide deck to show up reliably