Why ovens and cooktops need dedicated circuits

What a dedicated circuit is

A dedicated circuit is a circuit from the switchboard that supplies only one appliance. It has its own circuit breaker, its own cable and nothing else plugged into it. Ovens, cooktops, air conditioners, hot water systems and some pool equipment usually get dedicated circuits because of the amount of power they draw.

How much power cooking appliances use

A standard wall power point is rated at 10 amps. Many wall ovens, especially larger pyrolytic models, draw more than that when the elements are working hard. Cooktops, particularly induction units, can draw far more again. The exact rating is in the installation manual, and that's what decides the size of the cable and circuit breaker.

Some smaller ovens are designed to plug into a standard outlet. Most full-size ones are hardwired to their own circuit.

What goes wrong when circuits are shared

When a high-draw appliance shares a circuit with other loads, a few things can happen:

• The circuit breaker trips when the oven and kettle or microwave run together.
• Cables run warm because they're carrying more current than intended.
• Connections loosen over time with repeated heating and cooling.
• The appliance underperforms because voltage drops under load.

In older homes we sometimes find ovens connected to circuits that also supply power points or lighting. That might have been acceptable decades ago with older, smaller appliances, but not with modern ones.

Replacing an oven or cooktop

When replacing a cooking appliance, check the rating of the new one against the existing circuit. Like-for-like replacements often use the existing circuit without trouble. A bigger or more powerful model, a double oven or a switch to induction may need the cable and breaker upgraded.

Also check how it's connected. Some appliances plug into a dedicated outlet behind the unit, others are wired to an isolating switch. The manual will say.

Older switchboards

Adding or upgrading a circuit needs space on the switchboard and safety switch protection. Older switchboards with ceramic fuses can't easily accept new circuits, and some are already full. Customers have told us we found fire hazards in a meter box while doing other work, which is a reminder that an old board is worth a proper look before adding load. Our switchboard services page explains the signs.

Isolation for safety

Ovens and cooktops should have a way to isolate power for servicing, either a switch nearby or at the switchboard, as required. If you can't easily turn off power to your oven, that's worth fixing.

It also helps to label the switchboard clearly. When the oven circuit is marked, anyone in the house can turn it off quickly in an emergency, and an appliance technician can work safely without guessing. Many older boards around the Illawarra have faded or missing labels, and fixing that is a quick job.

Kitchen renovations

If you're renovating, plan cooking appliance circuits early. Decide on the oven and cooktop models before the electrician roughs in, so the cable is sized correctly. Our renovation and new home electrical work covers kitchens from start to finish, including the circuits for dishwashers and other appliances.

Warning signs

If your oven or cooktop trips the power, smells of burning, has scorched wiring at the connection or makes the lights dim noticeably when it's on, stop using it and get it checked. Our emergency electrician service runs 24 hours.

Let's get your kitchen wired properly

See our appliance installation page for more.

Call or text Kalani on 0424 400 346. Send the model of your new oven or cooktop and a photo of your switchboard, and we'll let you know what's needed.