Quick answer
A buzzing or humming DB board means connections are loose and heating up, and arcing at a loose terminal is exactly how distribution board fires start. This is not a noise to monitor for a while. Switch off the main isolator and call an electrician immediately. If you can smell anything hot or see any discolouration on the board, treat it as an emergency.
Common causes
- Loose busbar terminal arcing under load
- Loose breaker connection heating at the contact point
- Failing breaker arcing internally as its contacts degrade
- Overloaded circuit running continuously at its limit
- Corrosion on terminals in a damp or coastal-influenced environment
- Aluminium conductors on terminals designed for copper, loosening over time
What you can do now
- 1Switch off the main isolator
- 2Do not open the board or attempt to tighten anything yourself
- 3Look for discolouration, browning or melted plastic around any breaker, and mention it when you call
- 4Note whether the buzzing changes when a large appliance switches on
- 5Keep the area around the board clear and do not store anything against it
When to call a professional
Call immediately. DB board fires start exactly this way, and the interval between a buzz and a failure is unpredictable. A registered electrician will thermal-check and torque every connection, replace any degraded breaker, and should issue findings in writing. If the board is old, has re-wireable fuses, or lacks earth leakage, ask for an upgrade quote at the same visit.
Typical cost in Johannesburg
Emergency callout R750 · Repairs vary
Indicative ranges only. We provide written, itemised quotes before any work.
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