No hot water comes out of shower just cold comes out even when turned to hot, sink 2 feet away has hot water

This is going to be a water heater issue. Not the head.

did you turn on the hot water heater? water pump? limited,, and there is a nice dutchmen owners dot org site which I belong to,, alot of smart guys. good luck

Could be the pressure on the hot water flow is insufficient, you really need a 5/6 feet head of water from the shower head to the bottom of the storage tank for sufficient pressure.

How long has this been like this? Have you replaced any faucets, or have you installed a new water heater recently?

Has nothing to do with the expansion tank, the expansion tank whole enough air so that when the heater heats the water it does not build up pressure. You know from school that you can compress ait. you CAN NOT compress water. When you haet water it expands until it turns to steam. So lets rule that out.

First look at all the plumbing in the house where there is a cross conection. This would be like a shower valve that has a personal shower head on it. and you turn of the water using the personal shower handle and not the valve at the wall. This then would let cold water to go into the hot water side piping.

Most people do that with out knowing it at the laundry sink. they put a hose on to was the dog and forget to turn off the faucet and then BANG cold water in the hot side.

Go around the house and turn off all the faucets and valves by using the handles. no add on things.

Now last could be the shower valve itself. . Do this happen in just one shower or all of them???

If its just the one and you spend the day doing the walk around, even check the bidet if you have one

its the valve. you need repair to that.

Best of luck in your hunt Tom

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.

Lets watch a video

http://www.youtube.com/watch?v=J-SNBNijfQc

The hot and cold being reversed is an easy fix. When he took the handle off and exposed the cartage the small stem in the middle there are two flat spots on the stem with the screw hole in it just take some pliers and turn the stem 180% you don't have to turn the water off for this. DON'T TAKE THE KEEPER OUT FOR THIS!
If cartage dosen't want to come out as mentioned in the video be ferm with it but don't get ruff. If the cartage was hard to get out it is a good idea to sand or clean the hole it came out of some very fine sand paper wraped around a pencel well do the trick. If you do sand use a squirt bottle and wash any debree out of the hole.

As you look at your valve on the right you will see a large screw fitting.inside this fitting is a temp/ pressure balance spool. it has failed for some reason and needs to be replaced. On both sides of the valve are 2 smaller screws. these are the water shut off valves. turn off the water and remove the larger screw fitting. remove spool and replace. Hope this helps.

I found a way to get warm water in the shower, but I'm not sure it qualifies as a solution. After trying everything else I thought that maybe when I was feathering the faucet in the shower toward the cold side so I would get warm water that at a certain point it blocked the flow on the hot water side enough so that the sensor in the hot water heater sensed there was no demand in the line and it shut the water heater off. To test this, I went to the kitchen and turned the kitchen sink faucet all the way to the hot side and then turned it on so that I got a small flow of water. I waited for the water to get hot to be sure the hot water heater was working. Once it was hot, I left it running to keep demand in the line and then I went to the shower and turned the faucet on. When the water got hot I started feathering the control towards the cold side and soon I had warm water. So I think I'm right in that the sensor in the hot water heater was shutting the water heater off when the demand in the shower was lowered to a certain point when I was trying to adjust the water temp in the shower.

So now I can get warm water, but it means I have to leave the hot water running at another fixture in the house to create a false demand in the system so the hot water heater doesn't shut down. Is there a way to adjust the senor in the hot water heater so that it will stay on when I'm using the shower only, so I don't have to waste water by running another faucet when I want to take a shower?