Bath tub faucet will only run hot. Just started

Is the hot water pressure good at other fixtures in the house? I'm guessing your newer valves have a scolding adjustment that is set very low. Check the instructions that came with the valve assembly.

more specific please. so your saying that the actual faucet sticking outta the wall is PVC and not a Brass for plated brass pipe? Also what type of valve do you have. Is it a single knob valve that you rotate to turn on as well as adjust your water temperature, or is there 2 knobs one for hot and one for cold?

A picture would help me answer your question a lot easier

Bad single-handle faucet cartridge.
Bad check valve.
Bad mixing valve.
Test for crossover.
http://waterheatertimer.org/Crossover.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Sounds like the cause of your problem is the pressure balancing spool. Call Moen at
1-800-289-6636 and explain the problem. They will send a repair part to you free of charge. the link below is a "blow up" of your valve.

http://www.moen.com/shared/pdf/t3113pt.pdf

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!!!!

Hello,
There is a restriction in the faucet or the piping to the faucet on the hot wtaer side...this will be very hard to find and fix... The shower uses less water so it will get hot.... the tub spout allows more water flow so you cannot get the water more then warm...

Take the faucet apart and blow out all the passage ways with air... also run some water from the piping while the guts are out of the faucet, to flush the piping...
Hopefully this will fix you up...

Heatman101

Can you Isentify the make of the faucet?

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