Why does the power go off when I use the oven and hob at the same time?

Why the power goes off with the oven and hob: two causes

Oven and hob (cooktop) are the two most power-hungry appliances in a kitchen. When they run together, sometimes alongside the dishwasher or air conditioning, two very different things can happen, and each has its own fix.

If the whole house goes off: your contracted power

If the whole home goes dark and everything in your fuse box is still up, the ICP has acted. This power control switch is now built into the digital meter and cuts out when the total of what you have on exceeds your contract’s power (potencia contratada). With 3.45 or 4.6 kW it is easy to exceed it when cooking with everything on.

The fix is to spread out your use or increase your power. Increasing it has a fixed cost of about 30 euros per kW per year on the 2.0TD tariff, and sometimes requires a new boletín (electrical certificate).

If only the kitchen goes off: the circuit

If one particular MCB drops, the problem is the line. Spanish regulations provide a dedicated circuit for cooker and oven (C3) of 6 mm2 protected at 25 A, and an induction hob is fed with a 6 mm2 line and a 25 or 32 A breaker. In older installations the oven and hob often share a thinner cable or hang off the general sockets. Then the breaker trips or, worse, the cable heats up.

The fix is a dedicated line from the fuse box. As a guide, installing the line and connecting a ceramic or induction hob costs about 320 euros for a two-zone hob and about 450 euros for four zones.

How to tell which case is yours

1. When the power goes, open the fuse box.
2. If everything is up and there is no power, it was the ICP: switch off the oven or hob and wait for the meter to restore the supply.
3. If a breaker has dropped, it is the circuit.
4. If the RCD has dropped, it is not demand but a leak to earth.

When to call an electrician

Call if the kitchen breaker trips with only one appliance on, if the socket or the hob connection box feels hot, or if you want to switch to induction. A diagnostic visit costs roughly 50 to 100 euros, excluding 21 % VAT. In Seville, Spain we sort it out through increase contracted power and our air conditioning and appliances services. More answers in our FAQ.