Can I Use Multiple Heaters with Just One Thermostat? (2024)

5 min read

Sometimes we get calls from people who want to know if they can wire multiple heaters to one thermostat. The answer to that question is yes, you can wire multiple heaters to one thermostat -- if you're using 240-volt heaters and a 240-volt breaker. But that doesn't mean we always recommend it. Steve in our Tech Support Department says most of the time people want to wire multiple heaters to one thermostat for the sake of convenience. That makes sense if you have a larger room with multiple heaters in it or maybe an open-concept living space where a living room and dining room are one large area. Having one thermostat to control both heaters will work just fine because you're dealing with one larger space. It doesn't work with one thermostat in a bedroom controlling a heater in that room plus another one in a different room. The temperature in both rooms would be determined by the temperate of the bedroom with the thermostat. That just defeats one of the advantages of electric heat: heating rooms independently to maximize individual comfort and minimize the electric bill. Still reading? That probably means you're wanting to know how you can hook up multiple heaters to one thermostat. Here's what you need to know:

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
This helpful chart provides more information.


Size of breaker

Wire size

Maximum watts on circuit


20 Amp Double Pole12/2 with Ground



30 Amp Double Pole10/2 with Ground


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.)

This photo shows how you would connect wires to use multiple Com-Pak heaters to each other. One of the building wire lines (a.k.a. Romex) is going to the next heater, the other is coming from the wall thermostat. The looped copper wire would be connected to the green grounding screw in the heater wall can.

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


Add More to Compare Compare Show Differences Hide Differences Clear All


Can I Use Multiple Heaters with Just One Thermostat? (2024)


Can I Use Multiple Heaters with Just One Thermostat? ›

You can connect multiple heaters (baseboards, convectors, fan-forced convectors) to a single thermostat when the total power of these devices does not exceed the maximum load of the thermostat.

Can one thermostat control two heaters? ›

Having one thermostat to control both heaters will work just fine because you're heating one larger space.

How many heaters can I put on one circuit? ›

When placing multiple heaters on a circuit do not exceed the wattage listed for the corresponding wire and circuit breaker size. (For example: 2-1000W & 1-1500W, 240V heaters = 3500 Watts total. These 3 heaters would require 14/2 wire and a 20 Amp 2-Pole breaker if they were to all be placed on the same circuit.

Can you wire baseboard heaters in series? ›

Basically any number of heaters can be connected in parallel, but usually only two heaters are connected in series. Connecting more than two heaters in series becomes much more complicated. With heaters connected in series, if a heater fails it can affect the other heaters.

How many watts can a thermostat handle? ›

Thermostat Wattage

If the total maximum amperage is not listed, calculate the thermostat's wattage capacity by multiplying the voltage by its amps. In this case the thermostat (120V, 20A) can handle one or multiple heaters not to exceed the total 2400 watts.

How do you regulate heat in a two story house with one thermostat? ›

For winter heating, set the thermostat downstairs 2°F degrees warmer than the thermostat upstairs. As heat rises from the first floor, it will help keep the second floor comfortable too without wasting energy.

Can one thermostat control multiple zones? ›

With the invention of smart home systems, it is now even easier to control different zones of a home with one thermostat and multiple temperature sensors. Employing a modern-day zone heating and cooling system in your home requires an upgrade to smart home gadgets.

Can I plug 2 heaters into one outlet? ›

Never plug more that one space heater into a receptacle. Never use a power strip or surge protector strip.

Do electric heaters need to be on a separate circuit? ›

If your breakers trip when your heater is in use, then we recommend installing a dedicated circuit. This will help you stay safe while also ensuring that none of your other appliances are affected. Electricians will install the additional circuit by connecting it to your current electrical system.

How much is too much on one circuit? ›

As a rule of thumb, it's safest to stick to a maximum load of 1,500 watts per outlet or circuit. The number of things you can plug into one outlet depends on the wattage of each device or appliance you want to plug in.

Can you wire multiple baseboard heaters to one thermostat? ›

The short answer is YES, you can wire multiple heaters to one thermostat, but it depends on several factors to ensure your circuit can handle the load. See full Tech Article for more detailed info.

Does each baseboard heater need its own thermostat? ›

This allows them to counteract the cold air radiating off the window glass, as well as the areas where the home's greatest heat loss tends to happen. Electric baseboards are individually controlled, meaning each unit — and therefore each room — has its own thermostat.

What is the rule of thumb for baseboard heaters? ›

Myth #2: Bigger is Better. The rule of thumb for sizing a baseboard, or any electric heater, was 10 watts per square foot. So if you have a 10 x 10 room you would need a 1,000 watt heater.

What size room will a 1500 watt heater heat? ›

As a rule of thumb, you will need 10 watts of heating power for every square foot of floor area in a room. This means that a 1,500-watt heater can be the primary heat source for an area measuring up to 150 square feet.

What type of thermostat is typically used with electric baseboard heaters? ›

Line voltage thermostats are typically used for radiant, convection or resistance heaters that are powered by electricity. They are the type of thermostats to use with our baseboard and wall heaters.

Can you wire 2 electric baseboard heaters together? ›

As long as the sum of the two amperages is less than the size of the circuit breaker (20 amps in the case of baseboard heaters), then they both get what they need. If you put too many in parallel on the same circuit, you simply blow the circuit breaker and nothing warms up.

What is a dual control thermostat? ›

Two thermostats in one, the Dual Thermostat independently controls equipment heating and cooling systems.

Does two thermostats mean two furnaces? ›

Absolutely. One house can have two thermostats — the two thermostat units connect to one HVAC unit to make your home more comfortable by giving different zones a different temperature as desired. An HVAC professional will also install dampers and controls for better temperature regulation in those areas.

Can you run a 2 stage furnace with a single stage thermostat? ›

Any two stage furnace will have a control board that can be adjusted to use either a single or 2 stage thermostat. The control board will simply time the second stage if you use a single stage thermostat.

What happens if you touch two thermostat wires together? ›

Most thermostat wires operate on 24-volt power provided by a transformer, and they are generally safe to work on without shutting off the circuit feeding the thermostat wiring. However, if the low voltage wires touch each other during the work, the system's internal fuse will blow.

Top Articles
Latest Posts
Article information

Author: Tish Haag

Last Updated:

Views: 6079

Rating: 4.7 / 5 (67 voted)

Reviews: 90% of readers found this page helpful

Author information

Name: Tish Haag

Birthday: 1999-11-18

Address: 30256 Tara Expressway, Kutchburgh, VT 92892-0078

Phone: +4215847628708

Job: Internal Consulting Engineer

Hobby: Roller skating, Roller skating, Kayaking, Flying, Graffiti, Ghost hunting, scrapbook

Introduction: My name is Tish Haag, I am a excited, delightful, curious, beautiful, agreeable, enchanting, fancy person who loves writing and wants to share my knowledge and understanding with you.