Watts and volts are very important when picking out your new heater. And if you have that old heater, you just need to match the watts and volts from that old model to get the right replacement.
Wattage is essentially the amount of heat the unit puts out. And no, more isn't always better. It's important to have the right amount of heat for your room. Too much and your heater wont work properly. Too little and your room wont get warm enough.Voltage is the electrical supply going to the heater. Although your wall outlets are 120-volts, your larger appliances (and most heaters) are set up for 240-volts. These two aren't interchangeable. If you hook up a 120-volt heater to a 240-volt supply, it will quickly fail. If you hook up a 240-volt heater to a 120-volt supply it will deliver a quarter the heat it was designed to.
Thomas with our tech support team says that a lot of folks will recycle their heaters before buying a new one. Then one of two things will happen. They'll either be confused in the store when looking to find the right replacement or they'll assume they know the voltage and watts of the old heater -- and in that case they aren't always right. "It's important to keep that old heater until the new one is installed and running," Thomas said. Having that information will help you find the right heater without having to test the voltage of your supply line or do a new heat calculation for your room. Those things aren't too difficult if you know what you're doing, but it's a lot easier just to get the information from the heater you're replacing.