If both your toilet and bathtub are clogged at the same time, it could indicate a common underlying issue in your plumbing system. Here are a few possible reasons for this simultaneous clogging:
Main sewer line blockage: A blockage in the main sewer line can affect multiple fixtures in your home, including the toilet and bathtub. It could be caused by tree roots, debris buildup, or a collapsed pipe.
Clogged vent stack: The vent stack is a vertical pipe that allows air to enter the plumbing system, facilitating proper drainage. If the vent stack is clogged or blocked, it can create negative pressure in the system, leading to slow draining or clogs in various fixtures.
Shared drain line: The toilet and bathtub may share the same drain line. If there is a blockage in this common drain line, it can cause both fixtures to clog simultaneously.
In any case, it is recommended to seek the assistance of a professional plumber. They can diagnose the exact cause of the clog and implement the necessary repairs or clearances to restore proper drainage in your toilet and bathtub.