Single handle faucet in bath has no cold water and changes to hot less than half way over

Easy one.
Feel the pipes. The pipe on the right should be cold. If the pipes are correct, turn the cartridge 180 degrees.

If I understand correctly, you have single handled shower faucet.
Normally there is a wait for hot water to arrive at faucet.
But now hot water is already at shower faucet.

Single handled faucets have a mixing area inside valve where hot and cold come together before going into sink.
This mixing valve can have crossover where the hot and cold can pass through to each other even when faucet handle is off. When single handle faucets get old, this can happen.
How it happens:
For example another faucet is turned on inside house, and pressure differential between hot and cold causes hot water at shower handle to pass through mixing area and into cold water line.
So if another faucet has been run, then that lets hot flow to faulty single handled shower faucet.
To confirm this is the problem: turn on other faucet and put ear against shower faucet to listen for moving water.
This condition may also signal there is a water leak.
The problem is not harmful, but will draw cold water into water heater each time, and is energy wasteful.
Replace faucet or have plumber repair problem.

replace gaskets, and hot & cold water stems inside of manifold (turn off water first).

is this a standard bath tub?? if so the answer is no only pressure from hot/cold usually thru the access panel other wise you will have to crank up the water heater unless you have an on-demand water heater located near your access panel. which raises a second question. your faucet? is it a single handle for both hot/cold or two individual handles? if its a single handle try opening up your hot water valve in the access panel to allow for more hot water flow and slightly decresing your cold water valve hope this helps good luck!!!!

Remove the handle,and all the trim rings,and the cartridge cover. take a flat head screwdriver and use it to lift
up the red ring behind everything, this is the hot limit safety stop,
this just stops the handle from turning to full hot.

Once you have the red ring lifted up, notice the numbers and the pointer
on the ring, numbers are on the fixture,

O= hottest 7=cold

See what the ring pointer is set to now, and move it half, before you put this back together, just set the handle on the unit and run the water to see if its to hot or not enough. Once you have found what is the best setting, then replace all covers and trim, handle.

You probably have the cartridge in wrong. Turn it 180°.

Try draining the system and apply air pressure (min 30psi) to each faucet. Open other hot water faucets to allow pressure to vent. Next try draining and cleaning the hot water tank.

http://www.moen.com/contact.cfm?location=TopNavCustomerSupport

You will find a quicker answer and free parts for your bath room faucet at link above . I am sure it is the mixer valve assembly. If you are not a plumber I suggest a pro be called.

John

if the hot comes out when you first turn on you have hooked up hot and cold backwards

Usualy when this happens you need to change out the cartrage that controls the water. try to find your faucet at the link below. If you find it click on it scrol down and you can view the manual. It will terr you how to change it out.

http://www.deltafaucet.com/bath/index.html#tubshower_

Good Luck