Heaters that work with more than one voltage are called multi-volt or dual rated heaters. They can be wired to either of the two voltages listed on the product identification label. However, the wattage output will decrease by 25 percent at the lower voltage.
For example: A 240/208 dual rated heater can be wired to either a 240 volt or a 208 volt supply. If it’s 1500 watts at 240 volts, it will be 1125 watts at 208 volts.
Our Apex72, Register, NLW, ComPak, ComPak Twin, ComPak Max, ComPak Bath and Perfectoe heaters all have 240/208 options. The Energy Plus works in 120, 208 and 240 volt applications and automatically detects the incoming voltage.
Why should you care?
Electric heaters are designed to work at specific voltages. If you hook one up to the wrong voltage, it will either produce very little heat or it will quickly fail. Having a heater that matches your power supply is absolutely essential.
Multi-volt heaters give a little flexibility to contractors and people who sell our heaters. They can stock one heater that will serve multiple customers and work in multiple situations.
Honestly, if you’re a homeowner, the 208/240 volt dual rated heaters aren’t going to do a whole lot for you. Most homes have both 120 and 240 volt power but not 208 — that’s more of a thing in buildings with elevators. Where you will get some value is with the Energy Plus, which works with 120, 208 and 240 volt power. The Energy Plus automatically detects the incoming voltage and adjusts itself to work accordingly.