Flickering lights are one of the most common electrical complaints in Dunedin homes and across New Zealand. Sometimes the cause is simple, like a bulb that needs tightening. Other times, persistent flickering can point to a wiring issue that poses a real fire risk. Knowing the difference is what keeps your home safe.
This guide covers the most likely reasons your lights are flickering, what you can do about each one, and when it is time to stop troubleshooting and call a registered electrician.
The Most Common Causes of Flickering Lights
1. A Loose or Poorly Seated Bulb
The simplest explanation is often the right one. When a bulb is not fully seated in its socket, the connection becomes intermittent and the light flickers. Turn the power off, let the bulb cool, then tighten it firmly. If the flickering continues, try a replacement bulb before investigating further.
2. Incompatible Dimmer Switches
Older dimmer switches were designed for incandescent bulbs. LED bulbs have a very different power draw, and pairing them with the wrong dimmer often causes flickering or buzzing. Upgrading to a modern LED-compatible dimmer switch is usually a quick and affordable fix.
3. Loose Wiring or Connections
This is one of the more serious causes and, unfortunately, one of the more common. Loose wiring creates tiny gaps that electricity has to jump across, which causes a brief flash of light.
This is known as arcing, and it is a leading cause of electrical fires in New Zealand homes. If multiple lights are flickering across different rooms, loose wiring is a likely culprit. Do not attempt to investigate or repair wiring yourself. In New Zealand, all wiring work must be carried out by a registered electrician.
4. Large Appliances Competing for Power
When a high-demand appliance like a heat pump, washing machine, or microwave switches on, it draws a significant surge of current. This brief drop in available voltage can cause nearby lights to dim or flicker momentarily. The occasional flicker when the fridge kicks in is generally not a concern. Frequent or prolonged dimming when appliances operate is worth having checked.
5. An Overloaded Circuit
Every circuit in your home has a maximum load. When too many appliances or lighting fixtures draw power from a single circuit at the same time, the circuit struggles to keep up. The result is flickering lights, tripped breakers, or both. If your home is older, the circuit layout may simply not be designed for modern electrical demands.
6. Faulty or Ageing Wiring
Many New Zealand homes built before the 1980s still have original wiring. Over decades, insulation degrades, connections loosen, and the system loses its ability to deliver stable power. Many older homes in Dunedin and the Otago region fall into this category. Outdated wiring is a safety risk and a common source of persistent flickering. A registered electrician can assess whether your wiring is still fit for purpose and what an upgrade would involve.
7. Issues with the Switchboard or Meter Box
Your switchboard distributes power throughout your home. If a circuit breaker is loose, worn, or failing, it will not supply steady current to the circuits it controls. Lights flickering across multiple areas of the home, particularly alongside frequent breaker trips, can indicate a switchboard problem. For warning signs at home, see the signs your switchboard needs an upgrade. This requires professional inspection. A1 Electrical’s team can assess your switchboard and recommend an upgrade if needed.
8. Voltage Fluctuations from the Grid
Sometimes the issue originates outside your property altogether. A downed line, grid instability, or a problem at the transformer serving your street can cause voltage to fluctuate. If your entire street or neighbourhood experiences flickering at the same time, contact your lines company.
Simple Checks You Can Do Safely
Before calling an electrician, there are a few things you can check without any risk:
- Tighten the bulb in the socket and check whether the flicker stops.
- Try a replacement bulb of the same type to rule out a faulty globe.
- Note whether the flickering happens in one light, one room, or throughout the house.
- Pay attention to whether the flicker coincides with an appliance switching on.
- Check whether any other devices in the home are also behaving unusually.
These observations will help a registered electrician diagnose the problem quickly when they arrive.
When to Call a Registered Electrician
You should contact a registered electrician if any of the following apply:
- The flickering is constant or happening in multiple rooms at once.
- You can smell burning plastic or see scorch marks near a switch, socket, or light fitting.
- The flickering is accompanied by a burning smell, buzzing sound, or warm switches.
- Your circuit breakers are tripping alongside the flickering.
- Tightening the bulb and replacing it has made no difference.
- Your home has older wiring or a fuse-style switchboard.
In New Zealand, DIY electrical work beyond very basic tasks is illegal. Attempting to investigate wiring yourself puts you at risk of electric shock and could invalidate your home insurance. The cost of a professional inspection is far lower than the cost of an electrical fire. For what you can safely do yourself versus prescribed work, see when to call a licensed electrician.
If you are in the Otago region and experiencing persistent flickering, A1 Electrical’s EWRB-registered Master electricians in Dunedin are experienced in diagnosing and resolving flickering light issues safely and efficiently.
How to Prevent Flickering Lights
Regular electrical maintenance reduces the likelihood of flickering and keeps your home safer overall. A few habits that help:
- Choose quality bulbs and replace them before they completely fail rather than waiting for problems.
- Have a registered electrician check your switchboard and wiring if your home is more than 25 years old.
- Spread electrical loads across circuits where possible, rather than relying on one heavily loaded circuit.
- Upgrade dimmer switches when you transition to LED lighting throughout your home.
- Book a periodic electrical inspection every five to ten years, or when buying or renovating a home.
The Bottom Line
Flickering lights should never be dismissed as a harmless quirk. While the cause is often minor, it can also signal a serious wiring fault that deserves professional attention. If simple checks do not resolve the issue, the safest step is always to call a registered electrician. They have the tools and qualifications to find the root cause quickly and fix it properly.
