How do I take apart a 1675 shower faucet. The hot water is blocked and I think it may be the balancing unit that is blocked.

You haven't provided much information to help narrow down the source of the problem.

Is the flow of both hot and cold water flowing freely? Are the water lines not clogged internally with corrosion or residue? Is it possible that the water is being diverted such as in an apartment building or to an outside spigot (sprinkler system) or kitchen faucets (dishwasher)?
Is your water heater temperature setting correct and is it supplying sufficient hot water flow to the shower?
Do you have a temperature balance cartridge in your shower faucet? If yes, it could possibly be faulty.

Are you wanting to change/switch the hot and cold range of the shower or the temperature max and min? As for the range, the Monitor pressure balance valve may be having build up or problems. This valve controls the mixture of hot and cold water. To fix this, you will need to turn off the water supply, take the pipes apart and clean out the valve (I would recommend a professional). As for the max and min, you may just need to check the water heater pressure in your house. It may not be the faucet at all.

Elisa Jed ' http://www.ryansallglass.com/

When shower faucet apart make sure hot is getting 2 & coming out faucet ***. did you turn off stop integral w/ faucet or outgoing shut off valve on water heater.. May have rust or lime in small orifice leading to faucet ***. does your balancer/ piston move freely..good luck..

First try adjusting the pressure balancing gear located right behind the handle. If you still do not have hot water I suggest to replace the cartridge.

CHECK THE COLD VALVE RUBBER WASHER .

From what you've described, it's got to be a block between the main supply line and the shower head.

If you have never used this shower after its installation, it's possible that the temperature limit stop is set too low.

Otherwise, either the hot water valve or the balance spool need maintenance. The instructions on pages 4-6 of the link below should be helpful for correcting the problem.

http://www.moen.com/shared/pdf/instruction_sheets/INS162E.pdf

You bet....Pressure at the building varys with large use...8-10am or 4-6 pm....What floor you on...Higher the more pressure you need...maybe a pump...or plugged press.balance system....Not a novice handyman job...

Did this unit come with water stops built into the faucet body? Some of the newer faucets have stops built in and they need to be turned on. Also if you aren't going to plumb the hot in, you will need to cap it off but it should run without it unless it has some sort of balance in it. I don't think so though.

The cartridges in the single handle units are prone to display this issue in hard water areas as mineral deposits such as calcium build up on the stem. The stems also have small rubber band like rings - for lack of a better term- that break apart and can clog the ports on the side where the are on. New stem should resolve the issue totally unless you have had a pipe break or other construction to the plumbing system recently. Thanks for using Fix Ya.

you need to change the cartridge