A Buyer's Guide to Electric Heating Installation and Voltage

Winter is approaching, so it's time to start thinking about updating the electric heaters in your home or business. Whether you are updating existing heaters or installing new ones, you should understand how voltage matters in the installation process.

The most common voltage options for electric heaters are 120 volt or 240 volt. Higher voltage heaters draw more power from your circuit breaker, so it is important to know how much voltage your circuit breaker can handle.

When upgrading heaters, the easiest thing to do is match the voltage of the old and new heater. This is because a new heater’s voltage cannot exceed the old one’s, or it will overload the circuit. Hooking up to the wrong voltage can also cause you to only receive 25% of the total wattage of the heater.

For new and existing electric heaters, the easiest way to find its voltage is by looking at the product's label. You should always save or take a picture of the product label on your heater to keep track of its voltage. If it needs replacement or upgrading, you will need the label for reference.

If you do not have the label available, you can determine your heater’s voltage by checking your fuse box.

To determine what your space can handle, start by examining your electrical breaker panel. Electrical circuit breakers should have amperage marked on the toggle handle or on the top part of the module. You can also typically identify what voltage a breaker has by the type of switch it is, either single pole or double pole.

Generally, a 240-volt circuit breaker will have a double pole switch to support the large supply of energy that high voltage electrical appliances need. A 120-volt switch will normally be a single pole, which is the most common type of switch on a circuit breaker.

Single pole switches are simple, ideal for applications that only need an "on/off" switch. They power most household lights and lamps, and some smaller electric heaters use them.

Double pole switches are more complex, with two separate wiring connections instead of one. In homes, electricians use double pole switches for things like light and fan combinations. They also work with heavy duty appliances such as refrigerators, ovens, and washing machines.

For a more concise visual of voltage, amperage, and wattage comparisons, consult the table below.

Some circuit breaker fuses will look different from others depending on their age, brand, and what type of space they are in. In those cases, you will need to use a multimeter/voltmeter to test the power coming to the heater. This will require caution if you are doing it yourself, because you'll be testing live wires. Contact a licensed electrician to be safe when dealing with hazardous electrical wires.

120V or 240V Electric Heater?

The primary difference between 120V and 240V heaters is the amount of power they draw from the electrical panel. 120 volt heaters are more common because most homes have 120-volt circuit systems to install them on. 240-volt circuits usually power large appliances like dryers, water heaters, and HVAC systems.

If you're installing or replacing an electric heater on your own, it is easy to install 120-volt systems. Licensed technicians, on the other hand, typically wire a heater on a 240-volt circuit if available. This is because 240-volt systems have the same wire size and type as 120 volt, but are twice as powerful. 240-volt baseboard heaters are highly efficient for covering a large space.

The general recommendation for which type of electric heater you should install differs depending on your space. In most residential homes, a 120-volt heater will provide plenty of heat for a localized area. In commercial spaces, 240 volt heaters, the higher level of power will better cover the larger amount of space.

Browse HomElectrical's wide selection of electric heaters with different voltages to choose from to fit your upgrading needs. Start installing your new home heating system properly today with baseboard heaters, electric furnaces, and more.