Delta 134900 handle Water coming out faucet and shower both

Not usually, but there should be an inverter or other unit to activate the shower. Often it is in the tub outlet and blocks the tub outlet to force water up the shower pipes. If there is no such or if it is just not working you may need to run the piping up to a sufficient height and then back down to the shower head to create enough pressure resistance if it is as you say, requiring a specific height of pipe to get a specific back pressure. But there also needs to be a mechanism to force the water up the shower pipe. Look up Delta on the web and get a phone number as there will be someone at Delta that can fully advise you about this.

easy way is to install a shutoff valve on the shower head.

You need to replace the tub diverter/spout. There are two kinds, I hope you have the kind with
an allen head set screw on the bottom side of the spout near the shower wall. These are super
easy to replace ! Loosen the set screw, twist the spout a little and it should slide off. When installing
the new spout, smear some vaseline on the copper pipe sticking out, this will help seal the new O rings in the spout.

The other kind of spout has pipe threads in it. They can be a little more tricky. I got called to a
house one time. The plastic female threads on the spout cracked when the plumber installed it.
The water ran down the inside of the wall and did damage down stairs. The leak could not be seen
until the sheet rock down stairs fell down from being soaked. You need to put some pipe dope on the threads, then tighten the spout on by hand, so as not to scratch it with a pump pliers.

I hope this helps !

check the tub faucet the pull lever maybe slightly faulty causing back pressure in line and pushing water up to shower head --u may have debris in tub line causing partial blockage -or u have alot of water pressure coming in and it is to much for the lines to handle and it is pushing up to shower head

It's possible the diverter in the tub spout is jammed.

If you are handy, the best solution is to call delta and have them send you a new diverter. They will need the model of your faucet. The new diverter will come with instructions on the install process. As far as fixing it without the new diverter, I don't believe you will be able to.

You might have to replace the tub spout, because the divirter is not closing all the way. A new one will stop water from getting by it.

replacing just the handle cannot fix the leak and common sense should tell you that.... try turning off the water to the diverter (thru access panel on opposit wall or main water valve for the home) and then replacing the stem or cartridge inside the diverter -- this is what controls water temp, pressure, and is responsible for any leaks you may have...

The only possible explaination is that the water is finding it easier to go up than down. Water is lazy, just like me. ;)

Use an allen key to remove the tub spout. It's underneath and awkward. Once the allen key is loose, the spout just slides off. Try running the water. This may solve your problem and all you'll need is a new tub spout. If not.....

Turn the water off to the house.

Use an allen key to remove the handle.

Use a phillips to remove the trim plate (2 screws). Cut the silicone around the trim if it's there (which, in a proper installation it shouldn't be, but...)

Unscrew the nut (usually chrome) holding the cartridge into the brass body of the valve. The cartridge pulls straight out. Check for restriction in the ports of the cartridge itself. Check for restriction in the line going down to the tub spout. If you can't find anything, replace the cartridge.

Reassemble & Enjoy!

Remove hot/cold button in handle, remove screw/pull off handle. Remove the two screws in the wall plate/remove plate. Use a wrench to remove the diverter assembly. Get new diverter assy and reinstall eveything. You don't need to turn off the water.