Because the two pipes are connected, and the shower is farther down the line than the toilet. So when you flush, you are hearing the water from the toilet pass by your tub. This is also why you will have sewage in your tub if your waste water line is extremely backed up.
Check to see if the tank is full... if it is check why the pump is not emptying it. If it is empty then there is probably a clogged or missing vent.
The toilet may be empty due to a lack of water in the tank or a blockage in the pipes.
The toilet bowl is empty of water because the water has been flushed down the drain, carrying waste with it.
In the toilet
The toilet bowl is empty because there is a blockage in the pipes that prevents water from flowing into the bowl from the tank.
If you find an empty toilet bowl in the bathroom, it is best to flush it before using it to ensure cleanliness and proper functioning.
To empty a toilet for removal, start by turning off the water supply valve located behind the toilet. Flush the toilet to remove as much water as possible. Use a plunger to push any remaining water down the drain. Next, disconnect the water supply line and unscrew the bolts securing the toilet to the floor. Carefully lift the toilet and empty any remaining water into a bucket. Dispose of the water properly and prepare the toilet for removal.
The toilet bowl is empty because the water has been flushed down the drain, leaving the bowl dry until it is refilled with water for the next use.
If you find an empty toilet tank in your bathroom, you should check the water supply valve to ensure it is turned on. If the valve is on and the tank remains empty, you may need to contact a plumber to inspect and repair any potential issues with the toilet's water supply system.
To empty a toilet tank, locate the shut-off valve near the base of the toilet and turn it clockwise to stop the water flow. Then, flush the toilet to remove most of the water from the tank. Use a sponge or towel to soak up any remaining water in the tank.
A ceiling heat lamp should be placed over an empty space so that it doesn't overheat anything in the room. Putting the heat lamp over the shower rod could start a fire and over a toilet seat could make the seat too warm and burn someone.
To effectively empty a toilet bowl for cleaning, start by turning off the water supply valve located behind the toilet. Next, flush the toilet to remove most of the water in the bowl. Use a plunger to push any remaining water down the drain. You can also use a wet/dry vacuum to remove excess water. Once the bowl is empty, you can proceed with cleaning it using a toilet bowl cleaner and a brush.