Using this thermocouple is easy. First, make sure your gas hot water system is turned off. Then, carefully connect the thermocouple to the appropriate part of your heater using the brass adaptor nuts provided. After that, you can turn the system back on. When it comes to maintenance, it's a good idea to check the connections regularly to ensure they are tight. Also, keep the thermocouple clean from dust and debris. As for safety, always follow the manufacturer's instructions for your gas hot water system. If you notice any signs of damage or malfunction, stop using it immediately and consult a professional.