Moen shower faucet turns on when I turn it off

[Holly]

I am not a plumber - but have a moen rotating single handle shower faucet. When I turn it off (in 6 o clock position) it spurts hot water - if I turn it up to the 3 o clock position - the water turns off. If I try to turn the water on further (12 or 9 o clock position) it gets lukewarm, but not hot. I thought I would slowly take the knob off and see if I could adjust anything - but I ended up turning the two side screws for hot and cold adjustment or flow (?) and couldn't seem to get them back where they were originally. I got the hot water working again (6 o clock position) but the cold just dribbles. I guess I just need to reqdjust that part - but how do I get the water to turn on and off in the positions it should be at? My house is only 1 year old - and I have never seen this problem in any of the homes I have rented in the last 20 years. Is this something I can do - or do I need to call in a professional?
Holly

 

[Jimbo]

The screwdriver stops behind the plate are service valves. They must be left fully open. You have what is called the Positemp model. There is a sliding pressure balancing spool inside the cartridge, and they are prone to being stuck. You need to remove the cartridge, and rebuild it or replace it.

 

[Sponsor]

 

[Holly]

Thanks - I guess I am off to home depot in the morning - do i need to give them any information other than what I have given here? or do I need to get the special removal tool? One other question - to leave those valves open - is it the same - righty tighty lefty loosey? I am not sure if I got them back to where they were or how to make sure they are open.

 

[Dubldare]

Sounds like the handle is installed 180º off.

 

[hj]

valve

If the flow goes from hot to cold, then the inner core in in backwards. If so, then the reason you cannot get cold water is that the temperature limiting stop under the handle, which would prevent "HOT" water only from flowing, is now preventing the cold water only flow.