The kitchen sink backed up on a Sunday night. Of course it did. Water sat there, gray and still, with bits of last night’s dinner floating on top. I stood over it with my phone in my hand, already looking up emergency plumber numbers. My dad happened to call — perfect timing — and talked me through it in ten minutes.

I have not called a plumber for a clogged drain since. Here is exactly what to do, in order, before you spend a hundred and fifty dollars on a service call.

Start With Boiling Water

This sounds too simple to work but it works more than half the time. Boil a full kettle or pot of water. Pour it down the drain in stages — a third at a time, with thirty seconds between pours. The heat melts soap scum and grease that have congealed on the pipe walls. If the water starts draining, even slowly, you are on the right track.

Baking Soda and Vinegar — The One-Two Punch

If boiling water alone does not clear it, dump half a cup of baking soda down the drain, followed immediately by half a cup of white vinegar. Cover the drain opening with a plug or a wet cloth — you want the fizzing reaction to happen inside the pipe, not spray back out at you. Wait 15 minutes, then flush with another kettle of boiling water.

The reaction between baking soda and vinegar creates carbon dioxide bubbles that physically scrub the inside of the pipe. It also breaks down greasy buildup at a chemical level. This is the same principle as those foaming drain cleaners that cost eight dollars a bottle.

When to Use the Plunger — Correctly

Most people use a plunger wrong. For a sink, you need a cup plunger — the flat-bottomed kind, not the flange plunger meant for toilets. Fill the sink with enough water to cover the cup. Position the plunger over the drain and pump vertically, not at an angle. You are trying to push water through the clog, not splash it around. Ten to fifteen firm pumps, then check the flow.

If none of this works, the clog is likely in the P-trap — the U-shaped pipe under the sink. Put a bucket underneath, unscrew the slip nuts by hand, and clean the trap out manually. It is gross but it takes five minutes and requires zero tools on most modern sinks.