Several conditions contribute. Distance your shower stall is from the hot water heater. Type and age and size of pipe to your shower stall from your hot water heater and climate. Cold weather climate tends to cool the static water in the pipes while waiting to be turned on. Old pipes have a build up of rust / minerals inside slowing the normal flow. Distance, well it takes a while for the hot water to leave the tank and get to the faucet especially if the other two factors are involved.
If you can, insulate the pipes. This will help save energy and keep the water in the pipes hotter longer. If the water still takes an unacceptable time to warm up (Assuming you're only running the hot water to warm it up) you can buy a circulation pump that circulates water from the hot line to the water heater through the cold line. This means that you'll have hot water at the hot tap immediatly. (Actually, the circ pumps I've ssen for this job are usually timed) The down side is you'll also have hot water on the cold faucet too! If you can install a return line (basically another cold water line connected at the inlet to the water heater) the pump idea will work very well.
Turn on the hot water to the lav. and or tub. Then shut off faucet when water gets hot. It only takes a few seconds to do this. Then your shower will have hot water very fast.
The pressure reading of a hot water tank will also contribute to this problem. If the pressure is low and if distance is a problem this could equate for the long time for it to arrive. However, nowadays because of technology, most hot water tanks are made to the maximum pressure rating (600kpa) thus solving this problem. The idea above about opening a bath tap first is also a good idea.
Somebody running cold water or flushing toilet in the house..
In modern single piece shower controls, the system can break an o-ring or hard water can cause the cold supply line to become clogged at the smallest juncture.
Because after you've been in the shower for a while all the hot water gets used up so it goes cold.
The water heater may be filling with sediment making it harder for the water to heat and less volume of water available.
Evaporation or leaking somewhere.
means you are running out of hot water
You are running the water heater out of hot water faster than it can heat the incoming cold water.
No. All you get is smoke and steam. Not smoking stops the smell. Running water like that waste water as well.
They didn't shower. No one did in the 1800's. People washed in tubs of water or did a wash cloth type cleaning. Remember there was no running hot water so water had to be heated by bucketfuls to take a warm bath.
On single handle shower valves, designed to let cold water first and turn handle farther to mix hot water to desired setting. If hot water turned on first, possibility of getting scalded. If seperate hot/cold handles for shower, shower valve needs work.
yes you are even though you are not in the shower you are still wasting water
Replace the shower valve.
it depends on what your hot water level is
There are several possibilities; some of them indicate plumbing problems, and some of them are just consequences of physics. If the ceiling in the room with the shower drips all over during a hot shower, it may simply be that water vapor from the hot water is condensing on the relatively cool ceiling and dripping. If the ceiling in the room with the shower drips in a particular place, then it may be that the hot water pipe is leaking. (It's unusual for the hot water pipe to run through the ceiling instead of running up inside the wall, but it's not impossible.) It's also possible that it's condensation again, but that the condensation is only occurring at a particularly cool spot... perhaps where the ventilation system or a cold water pipe runs through the ceiling above. If the ceiling in the room underneath the shower drips after someone takes a shower, but only a hot shower, again it's probably the hot water pipe. If the celing in the room underneath the shower drips regardless of whether hot or cold water is used, then it's most likely a drip in the shower drain pan.
when hot waoter comes out of the shower you made have a water heater
Your hot water heater is not large enough.
When you take a shower, you're mixing a combination of hot and cold water to make a comfortable temperature for the shower water. A toilet draws only off the cold water system. In older or poorly designed plumbing systems, when you flush the toilet, the cold water is pulled by toilet, so the water coming through the shower is only drawing from the hot water tank.