Run a new cold supply line from the source. This will drain less pressure from the the cold shower line.
turn the pressure down at the toilet flush valve
Install a new pressure balancing valve in shower which helps with problem.
Because by flushing the toilet while using the shower, you have removed some of the water pressure on the cold side. This decreases the amount of water flowing to the shower head. Therefore changing the mix more toward the hot side. Answer this is also due to incorrect pipe size installation of cold piping. increasing the pipe sizing will solve the problem Installing a "pressure balanced" shower valve will fix the problem as well.
think the drain may be slightly blocked. Your best bet is to call a plumber now to fix it. If you leave it too long you may have toilet water coming up in other areas in your house. You can try to fix it yourself but most of the chemical treatments don't do a lot.
You can change the seals on your shower to ensure that you don't have a leak. You can also make sure that your fixtures are firmly attached to the shower head.
You repair or replace the shower control unit.
Someone installed the plumbing wrong. Instead of the water going down into the main lead, it's taking the other toilets route and flooding over, an easy fix unless you have to tear up the floor.
You either replace or fix the diverter behind the shower control. It's often just a broken seal jamming the pipe.
A broken seal would cause dirty water to jettison from a toilet. A plumber can fix it.
Remove the shower head and clean out anything that might be blocking it, such as hair or debris. Replace the shower head and turn on the water; the water should be running.
Clean or change the diverter faucet
If this noise occurs after shutting off a fixture (e.g., shower or sink), I'd pop the lid on the toilet tank and check there. Sometimes, this type of noise occurs when water pressure is reduced somewhere else, causing the fill valve to open slightly and howl like a foghorn. So, after shutting off the water and hearing the noise, pull up on the toilet tank float to see if it stops. If it does, replacing the fill valve will fix it.if still problem persist call for plumbing repair service.
Probably leaky drain pipe form toilet which passes through that room. Work out which corner of that room is below the toilet, you will probably see a swelling in the wall where the drain pipe is hidden. Call a plumber and get him to fix it.
What you probably need to do is snake out the vents. You probably have debris in them.1- you may have a slight blockage2- Poor venting and water Jetting will scour the piping rather then rodding
putt More water in the bowl
Water would drain from the toilet bowl if there is a crack in the lower part of the toilet. You would possible see water or signs of damp around the base. There is unfortunately no 'fix' for a crack in a porcelain bowl. If this is the cause then you need anew toilet.
New pressure balance faucet or you can install a pressure balance valve in the water lines behind tub or if you have a crawl space you can install it on the water lines there. But install only too the lines to tub faucet. And they are not easy no matter where you install. I would just tell everyone not to use any water till you are done with shower.
Either termper the water or fix the leak causing the sweating
The hot water side of your tub and shower diverter is plugging up. Replace the cartridge to fix the problem.
the shower and bath water comes from two different places so their is two different pipes. Get the shower pipe checked out by a plummer and they cause fix the pipe.
Drag them to the red boxes in the workroom , they will automatically fix the shower
Toilets that bubble when flushed and drain slowly can be cause by different things, such as port holes that are clogged, a clogged drain line, the tank has a low water level, or a problem in the vent pipe. A plumber can check for the specific problem and fix it.
From what I have seen from commercials, it should fix the hard water problem especially if you use a well. They showed people putting salt into the hot water heaters.