Globes and downlights keep blowing

First, work out whether it is one fitting or the whole house

If the same light fitting has eaten two or three globes and the rest of the house is fine, the globes are not the problem. Something in that fitting, or in the wiring behind it, is running hot, arcing or shaking. It will keep killing globes until someone fixes the cause.

Before you do anything else, check three things. First, how long each globe lasted. One that dies in days points at a bad connection. One that lasts a few months points at heat. Second, that you are fitting the right globe: correct base, correct wattage for the fitting, and a dimmable globe if it is on a dimmer. A non-dimmable LED on a dimmer will flicker and fail early. Third, the dead globe itself. Black scorching around the base or on the lampholder contacts is heat and arcing, not a dud globe.

If globes started blowing all over the house at once, stop there. That pattern usually means a supply problem rather than a lighting problem, most often a failing neutral, and it can take out appliances as well. Call someone rather than heading to the shops for more globes.

What it usually turns out to be

Across the lighting jobs we have run since 2020, the same handful of causes come up again and again.

• Heat with nowhere to go. A downlight in a sealed ceiling cavity, or with batts pushed over the top of it, cooks itself. Roof spaces in Craiglie and Port Douglas sit well over 50 degrees in the afternoon, so a fitting that would survive down south will not survive here.
• A loose connection arcing. A terminal screw that was never quite tight, or one that has worked loose through years of heating and cooling, arcs every time the light is switched on. That kills globes fast and leaves brown marks, a buzz or a hot plastic smell.
• The wrong or a cheap LED driver. Mismatched and no-name drivers fail early, and wet season humidity in a hot roof finishes them off. If the light flickers before it dies, suspect the driver rather than the globe.
• Vibration. Light kits under ceiling fans shake globes and cheap LED boards apart. So do fittings on a bouncy upstairs floor.
• Tired lampholders. Old brass batten holder contacts lose their spring tension, and salt air near the coast does not help. A globe sitting loose in a worn holder arcs at the contact.

What not to do

Do not fit a bigger globe to cure a dim light in a sealed fitting. You are only adding heat to a fitting that already cannot shed it. Do not pull insulation away from downlights and leave it heaped alongside, and do not push it back over them either. Do not keep re-globing a fitting that buzzes, smells hot or has browning around the lampholder, because that is an active arc in a timber roof space. Do not poke around inside a fitting with only the light switch off. Switching off at the switchboard is the minimum, and under Queensland law testing to locate a fault is energised electrical work for a licensed electrician.

What we do when we get there

We isolate the circuit, drop the fitting and look at the terminations, the lampholder and the driver for heat damage. We measure voltage at the fitting and check the neutral. We confirm clearances, whether the fitting is rated to be covered by insulation, and whether the dimmer and driver are compatible. If a whole circuit looks suspect we isolate and test it properly rather than guess.

Often the honest answer is that the fitting has had its day, and a sealed LED unit rated for insulation contact will outlast another year of globes. We will tell you which way we would go before we start. More on how we handle lighting work, or if a circuit is tripping as well, fault finding is the place to start.

Sources: WorkSafe Queensland, testing and energised electrical work.