BRK5 – RESETABLE FUSE (5 AMP)

A resettable diagnostic fuse for testing 24V HVAC circuits. The 5 Amp version of the BRK3 for systems with higher-rated fuses. Trips and resets instead of blowing, saving time and fuses during troubleshooting. Built-in light indicates when current is flowing through the circuit.

Specs: 5 Amp, resettable, built-in indicator light, auxiliary wires, by Supco

Replaces: BRK5, POP5

Fits: HVAC low-voltage circuit diagnostics — replaces the fuse temporarily while troubleshooting

In stock at Open To Public HVAC Parts in Dallas. We test parts at the counter before you buy. Call or text (214) 340-9421.

Specs

• TypeResettable circuit-breaker fuse
• Amp Rating5 A
• ResetManual push-button
• OEM CompatibilityUniversal

Cross-reference numbers

This part replaces the following OEM and aftermarket numbers:

• BRK5

Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.

Fits these models

• Resettable / circuit-breaker style fuse for 24V control circuit protection
• Replaces inline fuses on furnace and air handler control boards; press the button to reset after a trip
• Match the amp rating exactly to your existing fuse

My 3A or 5A fuse keeps blowing — what's wrong?

Something in your 24V control circuit is shorted or pulling too much current. Common causes: shorted thermostat wiring (animal chew, nick in insulation), stuck contactor pulling locked-rotor amps through the coil, failing transformer, or a shorted gas valve coil. Don't go up in amps — fix the root cause.

Can I use a higher amp rating?

No. The fuse is sized for your transformer and wiring. Going from 3A to 5A will let damaging current flow long enough to melt low-voltage wires or burn out the transformer. Match the original amp rating.

Where does this fuse go?

Typically on the control board between the 24V transformer secondary and the rest of the low-voltage circuit. Some equipment uses inline fuse holders. Check your unit's wiring diagram.

How do I test a blade fuse?

Pull it, check resistance with a multimeter. Near 0 ohms = good. OL / infinite = blown. Visual inspection through the clear housing usually tells you immediately.