My Dad recently passed away and with him pretty much all of the knowledge of the geothermal heating unit in my parents' house. The house was built in 2010 with geothermal heating, cooling and hot water. A month ago when we came to visit my mom for Thanksgiving we noticed that there was not enough hot water for more than one shower. She had recently had an annual maintenance inspection. I think the serviceman must have changed a setting. I'm hoping that there is a relatively simple fix that we can do while we're visiting my mom for Christmas, to fix the amount of hot water that is being stored. I took photos of the entire system if that would help anyone answer my question. I'll be happy to upload them if needed. There seems to be two hot water heaters. One is about 5 or 6 ft tall. The other is more like 3 or 4 ft tall. The shorter one has a gray tank looking item surrounding the exiting pipe that is maybe about 12 in in length and about 8in diameter. The taller one is wrapped almost completely in some sort of silver thermal blanket. Thanks for your help. Merry Christmas.