The number of heaters you can attach to one thermostat also depends on your circuit and wiring
The number of heaters that you can safely wire to one thermostat will depend on the size of your breaker in the electrical box, what type of wiring you are using and the wattage of the individual heaters. So a 240-volt circuit running on a 20-amp, double-pole breaker, can have any combination of heaters up to 3,840 watts. For example, using just one thermostat, you can install:- Two 1,500 watt heaters, or
- Three 1,000 watt heaters, or
- Five 750 watt heaters
Volts |
Size of breaker |
Wire size |
Maximum watts on circuit |
240 |
20 Amp Double Pole | 12/2 with Ground |
3840 |
240 |
30 Amp Double Pole | 10/2 with Ground |
5760 |
You must wire heaters in parallel, not series when using them with one thermostat
All heaters must be wired in parallel. You can either do that by connecting each heater to the thermostat directly, or by connecting each heater to the next -- just be sure that each heater is connected to the source wires. (You can also check out the wiring diagram at the top of this post -- it shows how to wire multiple baseboards together.)
I know that's a lot to take in. If you're at all confused, leave a comment and we will get back to you or get in touch with our Tech Support department. They'd be more than happy to walk you through the process over the phone or through an e-mail. If you're looking for more help finding the right heater or thermostat, check out more of our product selection blog posts including how to choose the right wattage heater and why you should consider upgrading from a baseboard to a wall heater.