Toilets not flushing properly can have a few different causes.
Here are a few diagnostic tips to help you correctly address the problem of having a poor flushing toilet. Go to the toilet you are having trouble with. Run water from a fixture higher than the toilet. If you have a sink in the area near the affected toilet, turn on the faucet and watch the water in the toilet bowl. If you notice turbulence or bubbling in the toilet bowl, there is your first indication, your toilet is not working well due to a blockage in the sewer line, beneath the toilet.
When the main sewer line to the building is becoming clogged or slow to drain, it will reveal itself in the way the toilet flushes. If you notice any of these signs: Bubbling, Gurgling, Slow drainage, the toilet will flush well after not attempting to flush it for a while then return to flushing poorly, don’t wait for the toilet to begin flushing normally. Slow running sewer lines normally get worse with use. Meaning, with each use, the sewer line is becoming more impacted. Waiting could mean while you are using water in a different part of the house, your sewer is backing up in the basement or wherever the lowest point of drainage in your house is.
If you don’t notice any of the above mentioned signs, your situation is not as bad as it may seem. You may be able to resolve a slow flushing toilet yourself.
Remove the tank lid and look for a stain created by normal water level on the side wall of the inside of the toilet tank. If the water level is lower than the staining, the flapper on the flush valve may not be creating a perfect seal. Energy and resource conservation studies have revealed a need for at least 1.6 gallons per flush for a toilet to effectively flush waste out of a toilet and provide enough flow in the sewer to disperse solids. This has become the standard for water consumption for water closets since September 14, 1998. Beware the plumber who advises use of bricks or filled jugs in the toilet tank. Water conservation is already at its lowest point. Using less water to flush the toilet only creates the potential for main sewer line backups. This also brings to mind, the fill valve may have been adjusted to not permit the tank to fill to the proper level.
If water is at the water line in the toilet tank, there may be a restriction in the main jet at the bottom of the toilet bowl. Or, calcium and mineral buildup in the jets at the rim of the bowl may be inhibiting the delivery of water to the bowl once the main jet has begun pushing water through the trap. The main jet begins the vortex action which creates a syphoning effect. The jets at the rim allow for the bowl to wash out as well as to supply the bowl with water until the syphoning has finished flushing waste from the toilet to the sewer.