Need to fix a leaking delta shower faucet and need to know how to take it apart. Single handle. only turns to left for on and farther left the hotter it gets,

adjust temp setting geared ring under handle to hotter

With some installations there is a setting screw to prevent the tap going all the way hot in an effort to prevent scalding to the elderly or children while in the tub/shower. You may have to take off the handle, and ring to check and see if this is the case, if so, a small adjustment to the screw inside will allow you to go beyond the current setting.

Please let me know if this helps and include feedback.

Those faucets are made by different companies and they put their name on them. Delta Price Pfister most likely. Sorry but you will need to pull it apart and see which it is. That is a hardware brand faucet and may be made by any of the major brands.

I can fix this.
What is the last thing you did before this problem started?

You would have to open up your drywall, cut and re-solder a new single handle faucet. An easier approach could be to shutting off your water supply, draining the lines in your bathroom from someplace below, and then trying to fix the bad soldered joint if you know how to do so.
I hope this helped.

First step remove handle and behind it there is a dial that looks like a gear. Mark where it is and remove it and put back in about a 1/4 to 1/8 turn counter clockwise to increase to hotter temp.

These faucets are equiped with anti scald setting's to protect the public and preset for this reason.

It takes a 1/8" allen wrench to remove handle. To increase hot water flow remove plastic dial that sets temperature. It is right behind handle and slides off stem for easy adjustment.

Remove indicator and replace about 1/8 to 1/4 turn counter clock wise to increase to hotter temperature.

you need to stick large screw driver up in the faucet and turn it counter clockwise. this might sound ridiculous but it works.

Hi Shannon:

The problem is most likely the seats and springs. You should purchase Delta Part # RP4993. I found some for mine at Lowe's for around $4.00. O-rings are available there too for about $2.00, and you probably should go ahead and replace them as well, especially if they feel dry and brittle.

You have to remove the handle, then unscrew the brass ring (or bonnet) with a pipe wrench, then just pull the cartridge straight out. Separate the lower cartridge from the upper by twisting a quarter turn to the left. Once separated, remove the black rubber seats and springs and install the new.

you have to take the handle off
there should be an insert that you can adjust by pulling out and turning