How Gas Cookers and Hobs Work

Understanding how your appliance is meant to work may help isolate what you need to fix in the event of a fault. This is the eSpares guide to understanding how your gas hob and oven work.

Natural gas is a colourless gas that burns very efficiently with a blue flame. Gas cookers have several advantages over conventional electric models:

• They provide heat instantly
• They don't retain heat for as long after being switched off
• Gas heat can be adjusted accurately

How a Gas Cooker Works:

1. Natural gas from the gas mains is piped to a connection on the back of the cooker. When you turn a cooker control knob to activate your hob burners, it opens a valve regulator, allowing the gas to flow through the jets of the burners.
2. When you press the cooker ignition (or on automatic models, when the action of turning a control sets off the automatic ignition), a battery or mains-powered electronic circuit produces a spark.
3. This spark ignites the natural gas, which is evenly distributed by the gas hob burners (see How a gas hob works below).
4. When you need your oven, you set the control to the desired temperature, which triggers gas flow through a burner at the lower back of the oven. Its flow is regulated by a simple oven thermostat. The top of the oven tends to be hotter than the bottom, which can be useful when cooking different dishes.
5. The grill works similarly, except the gas flames flow out from tiny holes in a central pipe across a metal gauze or grid. As the gauze heats up, it evenly cooks the food below.

How a Gas Hob Works:

1. When the valve on your gas hob is turned to the on position, gas flows through the supply pipe to the jet.
2. The jet is located under the burner.
3. From here, the gas is distributed evenly in a circle by the slots on the edge of the burner.
4. The burner cap protects the burner from food spills, and can be removed for easy cleaning. It also forces the gas to flow out through the slots.
5. When the ignition switch is pressed, or on some models any knob turned, a spark jumps from the ignitor to the burner, and the gas starts to burn as it exits the burner slots.
6. Rigid metal pan supports keep the pan level and away from the flame during cooking.

All cooker spares mentioned in this article are available at eSpares.co.uk.