Byron Knight — Licensed Electrical Contractor, Master Electrician

QLD Lic. 1511406 · 20+ years’ experience · Southern Gold Coast · Published 22 July 2026

A power bill that’s jumped for no obvious reason sends most people straight to “it must be the wiring.” Fair assumption, wrong starting point. In most of the calls we get about high bills, the actual cause is a specific appliance working harder than it should, not the electrical installation itself.

That said, there’s a real subset of cases where it is a genuine fault, and those cases usually come with warning signs beyond just the bill. Here’s how to tell which one you’re looking at.

Rule These Out First

Before assuming anything electrical, a few non-electrical explanations account for a lot of “why is my bill suddenly higher” calls: a change in your electricity plan or tariff, an estimated (rather than actual) meter read catching up, more people home more often, a run of hot or cold weather pushing air conditioning harder, or a new appliance that simply draws more than what it replaced. None of that needs an electrician, it needs a look at your last few bills and a call to your retailer if something genuinely doesn’t add up.

The Most Common Real Driver: Hot Water

Hot water heating accounts for around 23% of the energy used in an average Australian home, more in some households, which already makes it the single biggest hidden line item on most power bills. When a hot water system’s thermostat sticks or an element starts to fail, it can end up running for far longer than it should, sometimes close to continuously, and that shows up as a genuine spike rather than a gradual creep.

This is usually the first thing worth checking on a sudden jump, particularly if nothing else in the house has changed. It’s an electrical-side check, not a plumbing one, since the fault sits in the thermostat, element or wiring to the unit rather than the tank or pipework.

Standby Power and “Always On” Devices

Standby power, devices left plugged in and drawing a small current even when switched off at the unit, can account for up to 10% of a typical power bill. It’s rarely the explanation for a sudden spike on its own, since it tends to be a steady background cost rather than something that jumps overnight. But it’s worth knowing about, since it’s the most common reason a bill sits higher than expected without any single obvious cause.

When It’s Actually a Fault, Not Just Usage

A handful of genuine electrical issues can drive a real increase, separate from normal usage patterns:

• A pool pump or air conditioning compressor starting to fail, drawing more current or running longer to do the same job.
• A fridge or freezer seal that’s degraded, forcing the compressor to run far more than it should to hold temperature.
• A degraded or loose connection somewhere in the circuit, which wastes some energy as heat at the point of the fault, and matters far more as a safety issue than a billing one.

That last one is the important distinction. A loose connection or failing point in the switchboard isn’t usually the reason for a dramatic bill jump. It’s a fire risk that happens to show up faintly on a bill too, which is exactly why the warning signs below matter more than the dollar figure.

Warning Signs That Mean Stop and Call Now

None of these are billing symptoms first. They’re safety symptoms that happen to affect your bill as a side effect. Treat them as the priority they are.

How We Actually Find It

A proper fault check starts at the switchboard, checking for loose terminals, signs of heat damage, and safety switch performance, then moves to whichever appliance or circuit is the leading suspect based on what you’ve noticed. Thermal imaging is genuinely useful here: it shows heat building up at a bad connection well before it’s hot enough to smell, touch or trip anything, which is often the difference between a five-minute fix and a switchboard fire.

[E-E-A-T PLACEHOLDER: insert current indicative price range for a fault-finding visit / thermal imaging scan] Any figure is indicative only, and confirmed fixed-price on site once we know what we’re actually looking at.

Frequently Asked Questions

The Bottom Line

Most high power bills come down to hot water, a struggling appliance, or everyday standby load, not a wiring fault. But warm switches, a warm breaker, or any hint of a burning smell are safety signs that deserve a call regardless of what the bill says. Knight Electrical Solutions handles fault-finding and thermal imaging inspections across the southern Gold Coast under QLD Electrical Contractor Licence 1511406, quoted fixed-price on site.