|MadSci Network: Physics|
No, the thermostats on the water heaters do not have sensors to sense the altitude (or the atmospheric pressure), and only respond to the water temperature. If the water at one location seems to be hotter than at another, then the first location actually has hotter water.
Even if the thermostats on the water heaters appear to be set the same, manufacturing tolerances on thermostats can cause different thermostats to activate/deactivate at slightly different temperatures than the same type of thermostat set to the same temperature. I did a quick search using the Google search engine to find manufacturers of water- heater thermostats, and the several I studied indicated that the actual temperature of the water can vary by +/- 5 Fahrenheit degrees from the desired temperature.
John Link, MadSci Physicist
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