Is your oven light no longer coming on, making it difficult for you to monitor the progress of your food as it's baking/roasting? Here we explain the possible causes for this fault and how to resolve it.
THE POTENTIAL CAUSES FOR THIS FAULT:
Before you do anything to your appliance, make sure you disconnect it from the power supply.
There is a risk of electric shock.
Wear suitable protective gloves if you need to dismantle anything.
There is a risk of getting cut or injured.
The light is responsible for illuminating the interior of your oven. You can check the bulb by looking to see if the filament inside it is broken. If it has, you will need to replace it with a bulb of a kind suitable for use in your oven. These types of bulbs normally have 300°C printed on the cap. If the bulb you replace the old one with is not the right type, it could fail next time you use your oven.
The light socket brings the bulb into contact with the electric current. If the contact in the socket is faulty, the light will not come on. You can test if this is the case by placing the two probes of a multimeter (in AC voltmeter mode) on the socket's two terminals and checking to see if there is actually a current of 230 volts present. Use insulating electrical safety gloves when checking the voltage on the light socket to protect yourself against the risk of electrocution. If the bulb is new and there is definitely current present but the light won't come on, you will likely need to replace the socket.
The door safety lock ensures the door is securely closed (on pyrolytic ovens) and signals whether it is actually locked or not by means of a small switch. If the door lock is defective and won't activate when the door is open, the light will not be able to switch on. You can check the condition of the lock yourself. It will normally be located beneath the main control panel. Its striker pin may be bent or broken. You can also test the switch/mini-switch mechanism (which will be located behind the front panel) using a multimeter: check that it has continuity in one of its two positions.
The safety thermostat prevents the oven from overheating. If it's defective, neither the oven nor the lamp will be able to switch on. Oven thermostats can sometimes be tripped/activated by the cooling fan, a faulty sensor, or due to a fault on the thermostat itself. Some safety thermostats can be reset by means of a small button on their top sides, or by inserting the end of a paperclip into a hole in the middle. You can also check the condition of the safety thermostat using a multimeter in ohmmeter mode. Disconnect all the connectors and place the multimeter's probes on the thermostat's two terminals to test for continuity (you should get a reading). If it gives a null value, you will need to replace it.
The commutator provides power to both the heating elements and the oven light. Over time, the electrical contacts on commutators can wear out, resulting in the current no longer getting through. When this happens, the light will no longer be able to come on. You can check the commutator yourself. It can found on the back part of the oven programme selector knob on the main control panel. The fault will often be visible to the naked eye. You can also use a multimeter to check whether the contacts all have continuity when activated.
The terminal block, which can be found on the back of your oven, serves to connect the appliance to the electric mains circuit. If any of its screws are not properly tightened, or any of the wires supplying the light is worn or damaged, the oven will not be able to come on, which means the light will not come on either. You can try tightening the screws on the terminal block. If that doesn't resolve the issue, however, you will need to replace it.
The electrical wires and cables that link all the functional parts of the appliance together all have connectors at their ends, and these can become defective due to either electrical overheating or as a result of physical damage caused by them being twisted, bent or cut. If these kinds of issues occur, the oven will be prevented from switching on. You can check the condition of the electrical wires and cables; they can be found inside your oven's outer casing. You should be able to see if they're worn with the naked eye.
The main circuit board (PCB) manages all your oven's functions (convection fan motor, heating element, oven light, etc.). If everything else has been checked and the 230 volt supply is definitely reaching the circuit board, but the problem still persists, it may be that the board needs replacing. The electric wires can sometimes get trapped and come into contact with the metal body of the oven, which can end up damaging the component that supplies electricity to the light. You can either replace the circuit board yourself or call on the services of a manufacturer-approved engineer.