It depends on which type of water heater you are going to replace. If the type of your new water heater is the same as your old one, no question you can hire qualified technician to do installation by yourself. However, on-site sighting is necessary if your old water heater is gas-typed. Installation is allowed to process once the location and power supply status are approved by technician. For any enquiries, please inform our CS staff by sending photos of old water heater and installation site via installation@germanpool.com.