I have several hot water problems. It runs steaming hot in the kitchen, but luke warm everywhere else. Showers are the worst, although some showers (we have three) are worse than others. The water in the kitchen sink changes from steaming hot to ice cold to luke warm in a matter of minutes. The hot water pressure varies considerably, as well. We have a geothermal heating system in our home. Could the geothermal be influencing our hot water?