Can I replace this shower faucet to make my shower act more 'normal'?

Question

The nob on my shower (in my recently rented house) is unusual. Turn it to the left for cold water, turn it to the right for hot water... There seems to be no good middle ground. I've tried placing it in every possible position and nothing gives me good warm water.
I removed the nob from the wall to see if I could fiddle with the connection to fix it, but I got nowhere that way. Is there a way I can fix this with little plumbing skills (the best I have done is replace a garbage disposal) or will it take a plumber coming in charging me gobs of money?

Thanks for the response. I tried the full range of the water heater (110-150) and I got an almost reasonable temperature on the 110 setting, but it's still not comfortable for a shower. Winter does help also, the temperature isn't too bad now that it's 30 degrees outside (making the little bit of cold water coming through even colder)... but the problem will return in the spring.

A better description of the nob:
It is 1 nob that turns side to side (not up to turn it on like many shower nobs). If I turn it to the left slightly it is freezing cold. The further to the left I turn it, the warmer it gets... although it never gets warm enough for a shower in that direction.
If I turn it slightly to the right it is scolding hot. The further I turn it to the right, the cooler it gets... although it never gets cool enough for a comfortable shower in that direction.

I originally thought that the nob was simply installed improperly and I could flip it upside down or something along those lines to solve the problem. I can't imagine a modern nob is supposed to work this way (cold in 1 direction, hot in the other)... since most people like warm.

There is nothing clogging the hot or cold pipes since both very cold and very hot work great.

Answer 1

There are internal screens in the pathways inside the uni-valves. The pathway for the hot side maybe getting restricted. There are rebuild kits for most of these valves but it consists of a lot of "O" rings and little springs and stuff. If you are not comfortable doing that I would talk to the owner to see if he would have it replaced for you. If the valve is new another thing to check is under the cover there may be a limiter that physically stops the valve from going all the way to hot, this is to prevent kids from getting burnt. This is very easy to move.

Answer 2

check the temp setting of the hot water heater, it may be set too low,

Answer 3

There's a great plumbing guide here that might be if some help - http://www.channel4.com/4homes/diyandbuilding/DIY-Guide-to-Plumbing-Problems.html

Cheers

Answer 4

is it a moen??