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FUSE

Shop HVAC fuses at Open To Public HVAC Parts in Dallas. We carry time-delay fuses, fast-acting fuses, disconnect fuses, and automotive-style fuses for air conditioners, furnaces, and heat pumps. Common amperages in stock for same-day walk-in pickup.

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In-Store Pickup Only — Browse our catalog below, then visit us in Dallas or call (214) 340-9421 to purchase.
  • In Stock3AFUSE - FUSE
    UNIVERSAL

    3AFUSE – FUSE

    SKU · 3AFUSE
    $0.89

    3 Amp bladed ATC fuse for HVAC control boards and low-voltage circuits. Standard automotive-style blade fuse. Protects 24V thermostat circuits and control wiring.

  • In Stock5AFUSE - FUSE
    UNIVERSAL

    5AFUSE – FUSE

    SKU · 5AFUSE
    $0.89

    5 Amp bladed ATC fuse for HVAC control boards and low-voltage circuits. Standard automotive-style blade fuse. Common replacement on furnace and air handler boards.

  • In Stock9-115-34-1 - FUSE LINK ASSEMBLY (FIRST CO, N951-1)
    FIRST CO

    9-115-34-1 – FUSE LINK ASSEMBLY (FIRST CO, N951-1)

    SKU · FIRST COMPANY
    $11.84

    First Company 9-115-34-1 thermal fuse link assembly. 25 Amp, opens at 300°F. Ceramic body with stake-on terminals. Safety device for First Company HX coil units.

  • In StockBRK3 - RESETABLE FUSE (3 AMP)
    UNIVERSAL

    BRK3 – RESETABLE FUSE (3 AMP)

    SKU · BRK3
    $21.66

    Supco BRK3 resettable 3 Amp diagnostic fuse for HVAC low-voltage circuits. Built-in light shows when circuit is active. Resets instead of blowing — saves time troubleshooting.

  • Low StockBRK5 - RESETABLE FUSE (5 AMP)
    UNIVERSAL

    BRK5 – RESETABLE FUSE (5 AMP)

    SKU · BRK5
    $21.66

    Supco BRK5 resettable 5 Amp diagnostic fuse for HVAC low-voltage circuits. Built-in light shows circuit activity. Trips and resets without blowing — great for troubleshooting.

  • In StockFUS02295 - FUSE (TRANE)
    UNIVERSAL

    FUS02295 – FUSE (TRANE)

    SKU · FUS02295
    $15.10

    Trane FUS02295 time-delay fuse. 3.2A, 300V. Allows brief startup surges without blowing. OEM fuse for Trane furnace and air handler control boards.

  • In StockSTC4228 - TEMPERATURE FUSE LINK (L235°)
    UNIVERSAL

    STC4228 – TEMPERATURE FUSE LINK (L235°, 15A)

    SKU · NTC227
    $5.37

    Temperature fuse link, opens at 228°F (109°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC4257 - TEMPERATURE FUSE LINK (L257°)
    UNIVERSAL

    STC4257 – TEMPERATURE FUSE LINK (L257°)

    SKU · NTC257
    $5.05

    Temperature fuse link, opens at 257°F (125°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC4300 - TEMPERATURE FUSE LINK (L300°)
    UNIVERSAL

    STC4300 – TEMPERATURE FUSE LINK (L300°, 15A)

    SKU · NTC300
    $5.37

    Temperature fuse link, opens at 300°F (149°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC4333 - TEMPERATURE FUSE LINK (L333°)
    UNIVERSAL

    STC4333 – TEMPERATURE FUSE LINK (L333°)

    SKU · NTC333
    $5.28

    Temperature fuse link, opens at 333°F (167°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC4358 - TEMPERATURE FUSE LINK (L377°)
    UNIVERSAL

    STC4358 – TEMPERATURE FUSE LINK (L377°, 15A)

    SKU · NTC378
    $5.37

    Temperature fuse link, opens at 377°F (192°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC4438 - TEMPERATURE FUSE LINK (L438°)
    UNIVERSAL

    STC4438 – TEMPERATURE FUSE LINK (L438°, 15A)

    SKU · NTC438
    $5.37

    Temperature fuse link, opens at 438°F (228°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC4468 - TEMPERATURE FUSE LINK (L468°)
    UNIVERSAL

    STC4468 – TEMPERATURE FUSE LINK (L468°, 15A)

    SKU · NTC468
    $5.37

    Temperature fuse link, opens at 468°F (242°C). 15 Amp rated. One-time-use thermal safety device — if it’s blown, the system overheated and needs the fuse link replaced.

  • In StockSTC5257 - CERAMIC TEMPERATURE FUSE LINK (L257°, STRAIGHT)
    UNIVERSAL

    STC5257 – CERAMIC TEMPERATURE FUSE LINK (L257°, STRAIGHT)

    SKU · STC5257
    $17.65

    Ceramic temperature fuse link (straight), opens at 257°F (125°C). 15 Amp. Ceramic body for higher heat environments. Straight terminal orientation.

  • In StockSTC5300 - CERAMIC TEMPERATURE FUSE LINK (L300°, STRAIGHT)
    UNIVERSAL

    STC5300 – CERAMIC TEMPERATURE FUSE LINK (L300°, STRAIGHT)

    SKU · NTCD300
    $17.65

    Ceramic temperature fuse link (straight), opens at 300°F (149°C). 15 Amp. Ceramic body for higher heat environments. Straight terminal orientation.

  • In StockSTC5333 - CERAMIC TEMPERATURE FUSE LINK (L333°, STRAIGHT)
    UNIVERSAL

    STC5333 – CERAMIC TEMPERATURE FUSE LINK (L333°, STRAIGHT)

    SKU · NTCD333
    $17.65

    Ceramic temperature fuse link (straight), opens at 333°F (167°C). 15 Amp. Ceramic body for higher heat environments. Straight terminal orientation.

  • In StockSTC5377 - CERAMIC TEMPERATURE FUSE LINK (L377°, STRAIGHT)
    UNIVERSAL

    STC5377 – CERAMIC TEMPERATURE FUSE LINK (L377°, STRAIGHT)

    SKU · NTCD388
    $17.65

    Ceramic temperature fuse link (straight), opens at 377°F (192°C). 15 Amp. Ceramic body for higher heat environments. Straight terminal orientation.

  • In StockSTC6257 - CERAMIC TEMPERATURE FUSE LINK (L257°, ELBOW)
    UNIVERSAL

    STC6257 – CERAMIC TEMPERATURE FUSE LINK (L257°, ELBOW)

    SKU · NTCK257
    $18.69

    Ceramic temperature fuse link (elbow), opens at 257°F (125°C). 15 Amp. Ceramic body with 90° elbow terminal orientation for tight-fit installations.

  • In StockSTC6300 - CERAMIC TEMPERATURE FUSE LINK (L300°, ELBOW)
    UNIVERSAL

    STC6300 – CERAMIC TEMPERATURE FUSE LINK (L300°, ELBOW)

    SKU · NTCK300
    $18.69

    Ceramic temperature fuse link (elbow), opens at 300°F (149°C). 15 Amp. Ceramic body with 90° elbow terminal orientation for tight-fit installations.

  • In StockSTC6333 - CERAMIC TEMPERATURE FUSE LINK (L333°, ELBOW)
    UNIVERSAL

    STC6333 – CERAMIC TEMPERATURE FUSE LINK (L333°, ELBOW)

    SKU · NTCK333
    $18.58

    Ceramic temperature fuse link (elbow), opens at 333°F (167°C). 15 Amp. Ceramic body with 90° elbow terminal orientation for tight-fit installations.

Signs You May Need a New HVAC Fuse

HVAC systems use fuses to protect the low-voltage control circuit (typically 3A or 5A on the furnace board) and high-voltage disconnect fuses for the outdoor unit.

System Completely Dead — No Response
  • Nothing happens when the thermostat calls for heating or cooling.
  • The control board has no LED lights or diagnostic codes.
  • A blown 3A/5A board fuse kills the entire 24V control circuit.

If a board fuse blows repeatedly, there's a short somewhere — usually in the thermostat wiring or a sticking contactor coil. Don't just keep replacing fuses.

Outdoor AC Unit Won't Run
  • The indoor blower works but the outdoor condenser unit doesn't start.
  • Check the disconnect box mounted on the wall next to the outdoor unit.
  • Pull-out fuses in the disconnect can blow during power surges or storms.
🔄System Works Intermittently
  • The system runs sometimes but randomly stops.
  • A fuse that's partially blown or has a loose connection can cause intermittent failures.
  • Corroded fuse holders in outdoor disconnects are common in humid climates.
Not sure which part you need? Bring your old part to our Dallas store — our team will test it for free and help you find the right replacement.
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Call (214) 340-9421