Poor toilet suction leads to weak flushes, meaning you must flush the toilet multiple times to expel all of the waste in the bowl. Poor toilet suction may lead to complete blockages in the toilet's drain line as well as wasted water from flushing more than you normally would need.

Poor suction problems require you to flush the toilet more than normal.

Testing the Cause

When your toilet suffers from low suction, meaning that only a small amount of water flows down the drain with each flush, you must determine in general what is the cause of the suction problem. Toilets flush using gravity since the water rushes from the tank and into the bowl through a series of holes called ports. By pouring a large bucket of water rapidly in the toilet's bowl, you may determine if the problem involves the toilet's drain system or the passageway between the tank and the bowl.

Drain Clogs

If pouring the bucket into the toilet still does not produce a strong flush, you know the low suction problem has to do with the drain line. Using a plunger may dislodge a partial clog in the toilet's drain line since the plunger places pressure in the pipes. A funnel-cup plunger works more effectively than a regular plunger since the curved piece on the underside of the cup sits in the drain opening tightly. You may also feed a toilet snake or closet auger through the toilet's drain line, knocking the clog free.

Venting Problems

Venting problems also affect the toilet's drain line. The vent pipe connects to the toilet's drain line, helping expel sewer gases trapped in the pipes. Vent pipes also draw in fresh air from outside since the vent pipes open up above the house's roof. To check for obstructions in the vent pipes, you must climb onto your roof and use a flashlight to look down each pipe. If you see an obstruction but cannot reach it with any tools you have on hand, a garden hose with a high-pressure attachment may knock the clog free. A plumber has the ability to generate fake smoke in the vent pipes, helping locate not only clogs but also breaks or holes in the vent pipes.

Port Clogs

You need to clean out the port holes under the rim of the toilet's bowl if pouring the bucket into the toilet's bowl produces a strong flush. You may use a stick or wood toothpick to clean out the port openings, which may become clogged with hard water scale and other deposits. Cleaning out the entire passageway between the toilet's tank and the bowl may be the only way to eliminate the problem entirely. Create a cleaning solution by mixing one part muriatic acid with 10 parts water, which you pour down the tank's overflow tube. Allow half an hour for the mixture to break up the deposits, and then flush the toilet.