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220 Volt Electric Furnace Wiring

By Dave Rongey - Summary:

How to Connect the Electrical Circuit Wiring for a Furnace: The designation L normally means Line which usually has a hot from the circuit attached, not a neutral.

The Installation Manual for Proper Wiring and Connections

Electrical Question: I need help wiring an electric furnace with heat elements.

  • I have installed an electric furnace with a 15 kw heat element.
  • I ran number 6 wire with ground from my 100 amp service box where I installed a 60amp double pole breaker.
  • The furnace comes with an other set of breakers one 60amp and one 30amp where I am supposed to connect the line voltage.
  • I put the red wire in L1 the black wire in L2 and the white wire in L3 and the ground on the ground screw.
  • What goes in L4?
  • The blower comes on but no heat.

This electrical wiring question came from: Tony, a Handyman from Bloomfield, New Mexico.

Additional Comments: Good Questions and Good Answers

Dave’s Reply:
Thanks for your electrical wiring question Tony.

How to Connect the Electrical Circuit Wiring for a Furnace

Application: Wiring an Electric Furnace.
Skill Level: Intermediate to Advanced – Best performed by a Licensed Electrician.
Tools Required: Basic Electricians Pouch Hand Tools, electric drill, auger bits and extension cord.
Estimated Time: Depends on personal level experience, ability to work with tools and install electrical circuit wiring.
Notice: Installing additional furnace wiring should be done according to local and national electrical codes, with a permit, and be inspected.

Wiring Connections for 220 Volt Electric Heater

  • When wiring a furnace you need to check the wiring instructions for the units and the incoming circuits.
  • The designation L normally means Line which usually has a hot from the circuit attached, not a neutral.
  • Due to a lack of information about this unit I can only provide limited information.

Example of Wiring a 220 Volt Electric Heater:

  • Identify the Voltage
    • 208 Volt and 220 Volt Connections Wiring connections may need to changed depending on the voltage of the unit and the voltage at the location where the unit will be installed.
  • Electric Furnace Heating Elements and Heat Strips

    • The electrical circuit for an electric furnace will depend on the number and watt or kw size of the electric heating elements
    • In some cases, due to the electrical requirements,  it may be necessary to install a separate dedicated circuit just for the heating elements or heating strips.
  • Furnace Blower Motor Speed
    • Many furnace blower motors may be adjusted depending on the size of the home.
    • Confirm the proper speed setting and adjust the wiring connections at the wire terminal strip, or adjust the wire splices to the motor leads.
    • Unused wire leads must be capped off or relocated as instructed by the installation manual.

Electric Furnace Manual

Example of an Electric Furnace Wiring Diagram

electric furnace wiring diagram
Electrical Circuit Wiring for an Electric Furnace


220 Volt Wiring Diagram

  • Wiring 220 Volt Electrical Outlet
    • Home electrical wiring includes 110 volt outlets and 220 volt outlets and receptacles which are common place in every home. See how electrical outlets for the home are wired.

Learn How to Wire it Right with my
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Troubleshooting and Repair Electrical Wiring
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Electrical Codes for Home Electrical Wiring
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24 Responses to “220 Volt Electric Furnace Wiring”
  1. kent says:

    How can a 110volt fan circuit become energized with 220 on a Intertherm Ultraflex electric furnace?

    • Dave Rongey says:

      Hi Kent,
      If you are trying to add a 110volt fan to a 220 volt heater, the heater must have a 120/240 volt circuit which includes a separate neutral wire, and the heater must provide the ability for the fan to be added. It is important to understand that the additional fan must have proper circuit overload protection. If the furnace does not have the provision for the 110volt fan then a separate circuit may be required. Be sure the additional fan is properly integrated into the furnace system for proper control and operation which is permissible as an optional part of the furnace system.
      I hope this helps,

  2. Roy Bermea says:

    I had new furnace installed and ever since we started using the heater our electric bill has been sky high. I’m not even sure what brand it is, I tried to check but all I found was a sticker with model# serial # and just your basic info on furnace but could not see a brand or name. I know that it is connected by 2 60 amp breakers, our old unit only had 1 circuit breaker connected to it. I guess what I am trying to find out is how can I minimize how much electricity is used when the heater is on. I’m not sure if its wired correctly or if both 60 amp breakers are supposed to be used. It’s a big difference on how much electricity is used on this unit compared to our old unit. International comfort products, Model#Fem4p4800a volts 208/230.

    • Dave Rongey says:

      Hi Roy,
      There are several factors that would affect a high heating bill, however I think it would be a good idea to compare the new electric furnace to the old one to see how they compare. Special attention should be given to the efficiency ratings of each unit.

      You may consider contacting the installation company and explain your experiences to see if they can provide an explanation which would account for the higher electric bill. Perhaps the company will offer to come out and check the unit and the installation to make sure everything is performing properly, and examine the air ducts to make sure they are intact and not leaking. If the thermostat has been replaced with the new electric furnace make sure it is programmed properly for optimal performance and efficiency.

      I hope this helps you,

  3. John says:

    I had a Coleman 3400 electric furnace. I replaced it with a newer Miller model e2eb -017hb. There are two main power lines in and a ground. The new furnace has two breakers instead of fuses. What needs to be changed to make this work? There is 3 heavy gauge wires ran in but it has two breakers that takes 4 wires to connect

    • Dave Rongey says:

      Hi John,
      Check the installation manual that came with the Miller furnace to see what the circuit power requirements are concerning the amperage and voltage for each circuit.
      Identify the existing circuit power that was connected to the Colman furnace.
      Compare the circuit requirements.
      You may find that you need an additional separate circuit either for the heating elements, or a separate circuit for the furnace blower motor and controls.
      The existing circuit may not be used if it is rated smaller than either of the new required circuits.
      The circuit requirements will depend on the specific model furnace that you have.
      I hope this helps,

  4. John Kaminski says:

    My old electric furnace had 2 60 amp breakers in the unit and 2 60 amp breakers in the breaker panel of the house. Now the new furnace has a 30 amp and a 60 amp breaker. Do I need to change out one of the 60 amp breakers to a 30 amp breaker in the breaker panel?

    • Dave Rongey says:

      Hi John, Very good question!
      Because of the lower amperage rating of the 30 amp circuit of the new furnace, the existing 60 amp circuit that will be connected to the 30 amp circuit should be changed to the 30 amp rating. This will provide the necessary overload protection for the circuit wiring and internal furnace components that are part of that 30 amp circuit.
      Be Safe and Stay Warm and Cozy!
      PS: I Love the Ranch – GOOD for You!

  5. Ken says:

    I am installing a new 65000 BTU Winchester electric furnace and a 100000 BTU US Stove wood burning furnace. Is it possible to wire them so that the electric furnace blower comes on when the wood burner thermostat calls for heat? How would I do that. Do I need a limit switch or thermodisk on the electric furnace plenum? The wood burner is ducted into the electric furnace plenum but has it’s own limit switch on it’s cabinet. Is there any way to wire two furnaces to one thermostat to be set at different temperatures?

    • Dave Rongey says:

      Hi Ken,
      Installing an Electric Furnace
      Because you are installing a new electric furnace, and it no doubt is part of a system, I would recommend that you consult the installation and operation manual which came with this specific system. The controls and operations you have described should all be prewired as part of the system which ensure safety and efficiency.

      I will admit that I am interested in the wood burning furnace as described, and I will be doing some research on this topic.

      I hope this helps you, enjoy your new furnace system.

  6. Nelson says:

    We are installing a Goodman electrical furnace model ARUF 14 or ARPT 14 which has three heat elements that are supplied by a 60 amp and a 30 amp breakers. It has L1 and L2 on the 60 amp and L3 and L4 on the 30 amp. We only ran a # 6/2 with ground from the panel with a 60 amp breaker. Were we supposed to run another wire or a 6/3 ? Thanks for your help

    • Dave Rongey says:

      Hi Nelson,
      From what you have described the Goodman electric furnace may require two separate 240 volt circuits, one 60 amp 240volt circuit and one 30 amp 240volt circuit. However, I would advise you to consult the installation manual of the specific Goodman furnace that you have being careful to identify the exact model numbers for both the furnace and blower unit, and the heating elements, both of which will have their specific circuit requirements. The number of 240 volt circuits required for the heating elements will depend on the quantity of heating elements that are installed and how they are configured or prewired from the factory.
      I hope this helps,

  7. Hubert says:

    I have a new York electric furnace and to wire it up for 220 volt I only see L1 and L2, that are the black and red wires. I also hooked up the ground wire.
    But, in my cat 3 wire (required), there’s also a white neutral wire that as no place for it to be connected in the furnace.
    There is a 2nd ground screw in the furnace where I can hook a ground to, so I am wondering if I can hook the white (neutral) wire to the 2nd Ground screw in the furnace ? Or should I leave the white (neutral) wire unplugged with the pigtail? Thanks.

    • Dave Rongey says:

      Hi Hubert,
      The cat 3 wire that you are describing has nothing to do with the circuit power which is required for the electric furnace. In this case, the cat 3 cable may be intended for the thermostat and the control process of the furnace unit.
      The electrical circuit requirement(s) will specifically state if the unit requires a 3-wire or 4-wire circuit, and if the circuit requires a dedicated neutral wire, and if so then there will be a termination point provided specifically for the neutral wire. If your circuit wiring has a spare white neutral wire and your furnace specifications does not require a neutral wire then cap off the white neutral wire as a spare wire and do not attach it to the ground terminal. With equipment such as this ground terminals are for ground wires only. Please consult your electric furnace Installation Manual for specific detailed instructions.
      I hope this helps you,

  8. paul says:

    I have installed a GE electric furnace which has two 220 volt circuit beakers in the front section. Are both of these circuit breakers only for the heating coils? The blower motor just turns really slow and the coils will not heat up.

    • Dave Rongey says:

      Hi Paul,
      This would depend on the exact model electric furnace you have. If the heating coils are large, then they may require separate circuit breakers. Keep in mind that the power for blower motor for the furnace is most likely provided from a separate circuit or receptacle. If the blower is not powered, and there is no air flow through the unit then the heating coils will not heat up. The heating coils will be controlled by safety devices such as high temp switches and air flow switches. For complete information consult the installation manual or owners manual for your specific electric furnace unit.
      I hope this helps you,

  9. richard lee says:

    We installed a new furnace with a Duroguard electric heat kit. I am having problem with the wiring. The air kicks on but there is no heat. What do you suggest? It is all new, and there is a new Honeywell thermostat.

    • Dave Rongey says:

      Hi Richard,
      Double check the connections to the thermostat as compared to the furnace and the electric heat kit. It sounds like the thermostat is wired so the blower is being told to start instead of the heating unit. The thermostat should have a manual switch for the blower and the heat setting for the furnace. The wiring for these two functions may need to be reversed. You may be able to reference the old thermostat for the wiring configurations as well.

  10. lisa says:

    I need the wiring schematics to wire a Coleman Tappan Speedmatic Model 731 Electric Furnace.

  11. RICK says:


    • Dave Rongey says:

      I would look for a control circuit that may be starting the fan first then a circuit that would start and stop the heating coils. You may be attempting to wire the furnace direct, but instead you may need to wire in a control circuit. Basically something has to regulate and control the heating coils properly. With a typical furnace a thermostat sends control voltage which starts the unit, the fan starts, a sensor checks to make sure there is air flow, then if there is air flow the heating source is activated. The same process in reverse basically occurs after the desired temp is reached. The point is to not activate the coils unless there is air flow, and to make sure the unit is cooled off even after the heat has stopped.
      Look for the control circuit wiring diagram which should basically show a control circuit loop, where the control circuit is provided from a transformer or power supply.
      This should help get you going.

  12. Alex Leclerq says:

    I was thinking about buying a Coleman electric furnace but I’m not too sure these instructions would be compatible.

    • Dave Rongey says:

      Hi Alex,
      The instructions on this page about 220 volt furnace wiring may apply if the Coleman furnace you are referring to has the same specifications. Consult the installation manual which comes with the furnace to be sure of the circuit requirements and the wiring connections.

  13. Glenn says:

    I have a Dayton 2yu58 Electric heater.This unit can run on 208v or 240v. I have 220.What do I do?
    The specs on the unit say it requires 12 amps.The unit itself says it requires .25 amps(is that a misprint maybe?)
    The unit installation instructions say I only need 5/16 threaded rod to mount and install the unit. Does this mean I can wire it directly to the line voltage?
    I am wiring it for single-phase operation.


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220 Volt Electric Furnace Wiring

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