Quick answer
A brief dip when a large motor starts — a pool pump, an aircon compressor — is normal inrush and not a fault. Persistent flickering is different, and usually means a loose neutral connection, undersized cabling, or a failing earth leakage. A loose neutral is the one that matters: it arcs, heats, and is a genuine fire risk as well as a source of voltage that damages electronics.
Common causes
- Loose neutral connection at the board, a junction box or a socket
- Undersized cable on a circuit carrying more than it was designed for
- Failing earth leakage or main switch with degraded contacts
- Failing transformer or incompatible dimmer on the affected lighting circuit
- Loose or corroded connection at the supply point or meter
- Genuine inrush from a large motor, which is normal if brief and occasional
What you can do now
- 1Note whether the flicker is brief and only at start-up, or continues while the appliance runs
- 2Check whether it affects the whole house or only one circuit
- 3Listen for any buzzing at the DB board, which combined with flicker is urgent
- 4Note any recent electrical work, which often disturbs a neutral
- 5Reduce load on the affected circuit until it is investigated
When to call a professional
Book within the week, and same day if there is any buzzing or burning smell. Loose neutrals are a fire risk and they also allow voltage on that circuit to swing, which quietly destroys electronics. An electrician will check and torque the neutral connections through the board and the affected circuits, and test for voltage drop under load.
Typical cost in Johannesburg
Fault find R650 · Repair quoted
Indicative ranges only. We provide written, itemised quotes before any work.
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