From the first time that we discussed our proposed ground source district heating and water system, we have all struggled to understand how it really works! Now that we have installed it, we can feel how it works from being in the first house to make use of it. However, it still seems fairly miraculous, complicated and intangible. There are so many operations and actions that occur in the system that you simply can’t see. Having tried to explain the system to a range of people, including friends, colleagues, students and residents, I thought the best way was to draw it! I am still not sure that it is 100% accurate, but it gives a pretty good idea!