Using this universal water bottle cooler thermostat is easy. First, make sure to turn off the power of the cooler or freezer you're using it with. Mount the thermostat using the included mounting bracket in a suitable location. Then, attach the universal knob. To use it with a water bottle cooler, just set the desired temperature as you usually would. If you're turning a chest freezer into a keg cooler, set the temperature between 1 - 8 degrees Celsius. When using the on/off switch, turn it on to start the cooling process and off when you don't need it. As for maintenance, keep the thermostat clean. Wipe it gently with a dry cloth regularly. Avoid getting it wet. If you notice any issues, don't try to repair it yourself. Instead, contact us for professional help. And remember, since we have over 25 years of experience in the appliance parts business, you can rely on the quality of this product.