Oven Light On but No Heat? How to Replace a Faulty Selector Switch

⚠️ IMPORTANT: SAFETY FIRST

Before you touch any internal components, you MUST physically unplug the appliance or switch it off at the cooker isolation point. Electric cookers use high-voltage 240V circuits that can be fatal. If you are not confident using a multimeter or working with electrical wiring, please contact a qualified professional.

If your oven light and fan come on, but the elements stay cold, your Selector Switch is likely burnt out. The selector switch is the "brain" behind the knob that tells the oven which mode to use (Fan, Grill, Defrost). Over time, the internal plastic cams melt or the electrical contacts carbonize.

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Step 1: The "Visual" Diagnosis

Selector switches are hard to test with a multimeter because they have so many terminals. The easiest way to diagnose them is a visual check:

1. Safety: Power off at the wall!

2. Access: Remove the control knobs and the screws holding the front fascia.

3. The "Smell" Test: If you smell "fishy" burnt plastic near the knobs, it’s the switch.

4. The Visual: Look at the rear of the switch. If you see black carbon marks or a wire that has melted its spade connector, the switch is dead.

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Step 2: The "Marking" Technique (Don't skip this!)

A standard selector switch can have 10+ wires. If you mix them up, you could cause a dead short.

• The Black Ink Hack: Many ovens use multiple red or brown wires. Use a permanent marker to put "one stripe" on one red wire and "two stripes" on the other.

• The Map: Write down your own "wiring map" (e.g., Double Brown -> Terminal P1). Take a high-quality photo before moving a single wire.

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Step 3: Swapping the Switch

1. Remove Knobs: Pull them straight off.

2. Unscrew Fascia: Undo the screws (usually 2 per switch) that hold the switch to the metal frame.

3. One-by-One Transfer: Don't pull all the wires off at once. Move one wire from the old switch to the exact same terminal on the new switch. This is the safest way to ensure you don't make a mistake.

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Parts & Tools

• Replacement Switches: Buy cooker and oven spares from Ebay UK here 

• Essential Tool: Buy a good Multimeter here on Ebay UK 

So this is where the access for screws are on this cooker 

2 screw just undo them and screw with pull free from back hopefully

giving you enough room to check the terminations on the rear of switch unit 

ive pulled indicator lamp of here to save disconnecting it from switch 

here is the switch back and all connections best to photo it for 

replacement and to save issues and its also marked TOP so you know which way around it goes

there are 2 reds and 2 browns so i mark the second red and brown with black ink to

shwo me which ones are which and them basically go around and write down which 

wire colours go to which number terminal

So the double brown goes to terminal P1 an red 1 goes to terminal 2

and so on see how i wrote my terminations list in below photo

Once this is done pull the wires off and replace switch unit 

see video below of this entire process .