Many homeowners in greater Los Angeles experience a bathtub clog in their home, but not everyone realizes whether it is really a bathtub drain clog or a problem in the sewer line. As professional plumbers in Los Angeles, we see this type of thing all the time and know how to identify and locate the problem. We’re going to help you by giving you our secret testing techniques! So, to help explain the difference, let’s start picturing a bath tub clog when a person is taking a shower.Under normal circumstances, water should drain easily. The level of the water should never rise to your ankle level in the tub or standing shower. If the water level is increasing while taking a shower, there might be a drain clog in the bathtub or in the sewer line. There are three things you can do to know if the problem is in the bathtub drain or in the sewer pipe.First thing to check is, whether there are any bubbles or water coming out of the toilet in the same bathroom, when using water in the tub. If you turn on the water in the tub and the water overflows inside the toilet bowl, then it is very likely that the blockage is in the sewer pipe.Second thing you can do to differentiate the sewer problem from the bathtub drain is to shut off all the faucets in the bathroom, and try to flush the toilet a few times. After flushing the toilet, check and see if the water level rises in the bathtub. If it does go up, then the sewer line must be checked to locate the blockage in the sewer line.Third thing to do for checking whether a clog is in the bathtub or deeper in the sewer line is to turn on a sink faucet and watch inside the bathtub to see if water at the bottom of the drain elevates. If all the three steps rule out a sewer blockage, then the cause of the slow drain is in the bathtub pipes.Finding out where the problem of the clog is will give you a better understanding of what plumbing service to ask a plumber to perform in your bathtub, or, if it is a sewer problem, it will allow you to properly describe the situation to a plumbing service technician who can fix the slow drain issue permanently. In conclusion, bathtub clogs may surface due to a sewer blockage or the clog can simply be in the local pipes of the tub or shower drain. Knowing these plumbing tips will help you to locate the shower or tub drain problems easier.