In one of my bath rooms there is a tub (no shower). The house inspector did note that the temperature control was extremely difficult to move. It is the round type, where the control moves like the hand of a clock (don't know how else to describe it). How do I fix this?

If I understand you correctly, it is a single handle faucet. That is how you describe it. One knob in the middle, right? Either you rock it up and down for water on/off and twist it left/right for hot/cold, or it rocks in all directions; up/left hot, up mix, up/right cold. The former case is more common (Delta, American Standard) and usually cheaper to fix; the latter is less common (Valley, Peerless) and more prone to trouble and more expensive to fix (but not by much).

It could be adjusted wrong, depending on the brand. More likely, it needs to be rebuilt. Typically, you would remove the knob from the shaft. This might be accomplished by loosening an allen screw that will probably be on the bottom side of the knob and somewhat concealed, or you might pry off the center cover of the knob and remove the screw you find underneath. If, that is, it will come out.

Once the knob is off the shaft, on many brands you will see a threaded ring-like structure with two notches 180 degrees apart, that threads into the top of the faucet housing. This is a tensioning ring; it is made either of plastic or brass. Try loosening it with an appropriate tool and see if the faucet then moves more easily. If you loosen it too far, the faucet will spray water out of the housing when you turn it on. If you can make the faucet move easily without spraying, you are done.

More likely this won't work and you will have to disassemble the faucet. Turn off the water to the tub at the main. The entire top of the housing is threaded on. The top is dome shaped, and around the "base" of the dome - where it meets the housing - there will be knurls. It will come off, though it could be a major job to get it to come off. A pipe wrench will generally remove it, but will also generally score the knurls. This is an appearance issue, but might be unavoidable if the thing has been assembled so long that it is limed/corroded together.

Once you have it off, pull out the guts. Depending on the make, these will be a mixture of plastic, rubber, and metal. In the back of the housing, you will find two rubber or hard plastic seats sticking back into recesses in the housing. They have springs behind them. Remove them. Use whatever force is necessary; you won't be putting them back.

Off to the store. Buy replacements for all plastic and rubber parts, most especially the seats. Replace the seat springs as well (will be part of the seat kit).

When reassembling, a bit of vaseline on all parts that slide across each other makes things go much easier.

With a bit of care, it isn't too difficult a job to do.

About the Author: Jim Locker is a technical guy who has done a lot of real estate investing and landlording. The experiences he writes about and advice he gives are either first hand, or in answer to specific questions posed by others. He is commonly known as jiml8 around the internet.