As a child, did you ever play “I Spy”? It’s an easy game that involves you finding a nearby object and giving a clue to someone else. Then you see if you can guess what they are with your tiny eye.

We homeowners play a similar, but not as fun version of the game: identifying home problems before they become major issues.

You can use several senses to spot common plumbing problems such as a clogged drain. These are the signs of a blocked drain.

A toilet, sink, or tub drain is slowing flowing (or has stopped completely).

This is the most obvious sign that there’s an obstruction. If only one fixture is affected, it is likely that the blockage is caused by the trap. This is the U-shaped portion of the drain pipe that holds water and prevents sewer gases from rising. It should be possible to push the blockage out of the trap and fix the slow drain.

Running water in the bathroom causes the toilet bowl to overflow with water

Because the drains in a bathroom are connected at one point, if one fixture or socket affects the water level of the other, it is usually a sign that there is a blockage in the drain line.

Multiple drains are slow at the same time

If you notice that your drains are acting up in a hurry, it could be a sign that there is something wrong with the sewer line. This is the underground pipe that transports wastewater to the municipal sewer system. You should not ignore this type of blockage or you might end up with sewage backing up in your home.

Bad smells

A plumbing blockage may cause a foul-smelling odor in your home that isn’t visible. It could be organic materials (common on kitchen countertops) or the launching of a sewage backup due to a blocked sewer line.

Strange sounds coming from pipes

The majority of pipes are hidden so it is important to listen for signs of a blockage. You might hear a clog as bubbling, hissing or banging.

Next steps

The location of the blockage and its severity will determine how to unclog it. If you only have a slow drain in your bathroom or bathtub you can try to unclog it with a bent wire. If the blockage is deeper than the plumbing or affects multiple sockets, you should have a professional plumber look at it.

Also, we recommend that you don’t use gel drain clears or liquid drain cleaners to clean any drain. These products can cause poisonous fumes that can damage your plumbing.