Shower control knob thing

[Max]

When I shower I find that I have to sometimes turn the shower knob to a different position to get the same temperature water coming out. It seems to me that I should be able to turn the knob to the same place each day and get the same temperature water coming out. Is that a fair assumption? If so then is it a common task to replace it the control knob? I shower at pretty much the same time each day and there is no other water usage occurring at the same time.

Cheers, Max

[SSN596]

Tell us what brand and model you have. It may or may not be a probelm with the valve.

[Max]

I wish I could, there is nothing on it other than "Model B" (and the usual Hot, Cold)

[LazyPup]

There are an infinite number of conditions that will cause the temperature to vary from day to day or even hour to hour.

The thermostatic control valves that are commonly available for residential application are only intended to maintain the temperature that is set at the time,

There are commercial mixers available that can be set by a specific temp but they are extremely expensive and normally only used in hospitals, schools or geriatric facilities because they start out at about $1200 and require a constantly regulated source of hot water between 150 and 180deg..

[Max]

Thanks LazyPup. The reason I thought there might be a problem is that in other places that I have stayed at for an extended peiriod of time I've noted that turning the knob to a particular placed yielded the same results. It's not a big deal, I've enough things to be fixing so I shouldn't be looking for more projects.

Cheers, Max