Switchboard buzzing, humming or hot to touch

Turn off what you can and stop using the board

A switchboard that buzzes, hums, crackles or feels warm is not doing something normal. Turn off the circuits you can manage without and ring an electrician. Do not open the board yourself.

What causes it

• A loose termination. By far the most common. A loose connection arcs, and arcing makes noise and heat. It gets worse, not better.
• An overloaded circuit or main. Common where load has been added over the years without the board being upgraded: air conditioning in every room, a pool, a shed, an induction cooktop.
• A failing breaker or safety switch. They wear out, particularly in a humid coastal environment.
• Corrosion. On a coastal block or in a board with poor sealing, salt and moisture get into the busbar and terminations.
• Old rewirable ceramic fuse boards that were never designed for modern load.

How we find it without guessing

A loose or corroded termination gives off heat and a distinct arcing sound before it fails completely. We isolate and test circuit by circuit at the board to find which one it is, rather than guessing and replacing parts that were never the problem.

Where the noise is intermittent or load related, a power quality logger left on site over a few days will show what is actually happening rather than what someone thinks is happening.

When it turns into a board upgrade

Sometimes tightening a termination is the whole job. Sometimes the board is full, corroded, or has no room to add the protection the installation actually needs. We will tell you which, and we will not tell you a ceramic fuse board is illegal, because there is no Queensland law that says it is. What we will tell you is what it does and does not protect, and what it will cost to fix properly.

One thing that does force the issue: if you have recently bought the property or started a new tenancy, Queensland gives you 90 days to have approved safety switches on the general purpose socket-outlet circuits.

Sources: Electrical Safety Office and WorkSafe Queensland, 2024 amendment regulation.