How to Find a Clogged Pipe
- 1). Examine drain filters to determine if there is something on them that is causing the blockage.
- 2). Test the drainage at fixtures to determine if the clog is systemwide or confined to a particular area. For example, pour water in the drains in the kitchen and bathrooms to see if one drain or all drains are clogged. If only one drain is clogged, it represents a localized clog rather than a system problem. However, if all drains are affected, this is a symptom of a main line clog.
- 3). Turn on each water faucet in your home and note how the water comes out. If it comes out normally, this rules out water pressure problems and indicates the clog isn't affecting pipes feeding that particular faucet. If the flow starts strongly and tapers off, this represents a localized clog in the line feeding that faucet.
Source...