Few situations are as frustrating for homeowners as discovering their furnace not getting power in the middle of winter. When your thermostat reads “heat on” but nothing happens, or there’s no power to furnace, it can leave you cold, confused, and uncertain where to start.
If you own a Goodman MBVK electric furnace, understanding why your system is not receiving power—and how to safely diagnose it—is the first step toward restoring comfort. In this article, I’ll walk you through the most common causes, troubleshooting techniques, safety precautions, and how the MBVK’s design helps prevent power issues in the first place.
Understanding Why a Furnace Might Not Get Power
An electric furnace like the MBVK depends entirely on electricity to operate. Unlike gas or oil furnaces, there is no combustion; no flame, no igniter, no fuel delivery system. If power is interrupted, the furnace cannot heat, circulate air, or operate its safety controls.
Common reasons for a furnace not getting power include:
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Tripped circuit breakers or blown fuses
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Blown internal fuses or high-limit switches
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Faulty thermostat or control board
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Loose or disconnected wiring
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External power interruptions
When you encounter no power to furnace, the issue may be with the furnace itself, the home’s electrical system, or even a simple oversight such as a switch being off.
Step 1: Check the Circuit Breaker or Disconnect Switch
The first place to look is always the main panel. Many homeowners overlook the obvious: the breaker may have tripped.
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Electric furnaces are considered continuous loads, which means the breaker should be sized at 125% of the furnace’s rated amperage. An undersized breaker can trip frequently, leaving your furnace powerless.
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Check the breaker labeled for the furnace or its disconnect switch, usually located near the unit.
If the breaker is tripped:
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Switch it fully to OFF, then back to ON.
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Confirm the panel wiring is secure and meets NEC standards.
If the breaker continues to trip, the furnace may have an internal fault, such as a shorted heating element or control board issue. For guidance on electrical safety and troubleshooting, Electrical Safety Foundation International provides detailed resources.
Step 2: Inspect Internal Fuses and Safety Devices
The Goodman MBVK has several internal safety devices that can interrupt power if a fault is detected:
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High-limit switches – Prevent overheating
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Internal fuses – Protect the control board and heating circuits
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Sequencer relays – Manage staged heating
If a safety device trips or a fuse blows, the furnace may appear completely dead even if power is reaching the unit.
To check:
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Turn off power at the main breaker.
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Open the furnace access panel following manufacturer instructions.
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Inspect fuses for continuity using a multimeter.
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Check that high-limit switches are not engaged or stuck.
Replacement parts for these safety devices can be found at licensed distributors, but any replacement should follow the manufacturer’s specifications to ensure proper operation. For technical reference, Goodman provides manuals and component guides.
Step 3: Verify Thermostat Operation
A thermostat that fails to signal the furnace can make it seem like there is no power to furnace, even when the unit itself is fully energized.
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Confirm the thermostat is in heating mode.
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Check that the temperature setpoint is above room temperature.
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Inspect wiring connections between the thermostat and furnace control board.
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Replace batteries if applicable.
If your thermostat is not sending a heat call, the MBVK will remain off, giving the appearance of a powerless furnace. HVAC industry standards from HVAC.com note that low-voltage control issues are a leading cause of “furnace not getting power” complaints.
Step 4: Inspect the Furnace Control Board
Modern electric furnaces like the MBVK rely on a control board to manage:
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Blower motor operation
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Heating element sequencing
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Safety interlocks
A faulty control board can prevent power from reaching key components, causing the furnace to remain off. Signs of a board failure may include:
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Blower does not start even with a heat call
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Indicator lights or error codes are inactive
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Fuses on the board are blown repeatedly
Diagnosing a control board issue often requires a licensed HVAC technician, as it involves high-voltage circuits and sensitive electronics.
Step 5: Check Wiring and Connections
Loose, disconnected, or corroded wiring is a surprisingly common cause of furnace not getting power. Inspect:
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Main power leads entering the furnace
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Connections to the control board and blower motor
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Low-voltage thermostat wires
Always turn off power at the breaker before inspecting wiring. For safety, only qualified personnel should repair or replace wiring to maintain NEC compliance. For reference on proper wiring practices in electric furnaces, Energy.gov provides technical guidelines.
Preventing Power Issues With the Goodman MBVK
The MBVK is designed to reduce many of the causes of power interruptions:
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Staged electric heating elements reduce surge currents
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ECM blower motors allow smooth startup and protect circuits
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Integrated safety switches prevent overheating and minimize component stress
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Clear labeling and accessible panels simplify maintenance
These design choices mean fewer breaker trips, fewer blown fuses, and more reliable operation compared to older or generic electric furnace models.
Safety Considerations
When troubleshooting a furnace that is not getting power, always prioritize safety:
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Turn off the main breaker before opening the furnace panel
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Use insulated tools when checking electrical components
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Avoid bypassing breakers, fuses, or safety switches
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Contact a licensed HVAC technician for repairs involving high-voltage circuits
Electric furnaces may seem simple, but a minor oversight can lead to serious hazards.
When to Call a Professional
If your furnace shows no power after checking the breaker, thermostat, fuses, and wiring, it’s time to call a professional. A licensed HVAC technician can:
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Test the control board and sequencer relays
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Inspect high-limit switches and internal wiring
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Verify proper voltage supply and breaker sizing
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Ensure compliance with NEC and local electrical codes
Professional service ensures safety, reliability, and longevity for your MBVK electric furnace.
Final Thoughts from Jake Lawson
A furnace not getting power can feel alarming, but with a methodical approach, most issues can be identified and resolved safely. The Goodman MBVK electric furnace is designed to prevent many common power interruptions with staged heating, integrated safety features, and accessible wiring.
By understanding the role of breakers, fuses, thermostats, and control boards, homeowners gain confidence in diagnosing and preventing power issues. Proper installation, regular maintenance, and attention to electrical safety are the keys to ensuring your MBVK delivers reliable heat all winter long.
When your furnace has power and all systems are functional, you’re not just warm—you’re confident in a safe, efficient, and dependable electric heating system.
