What Is an Oven Thermostat and When Does It Fail?
The thermostat controls oven temperature by switching the heating elements on and off to maintain the level you set. When it fails, your oven may run too hot, too cold, or cycle erratically — ruining food and using excess energy.
Thermostats are mechanical components that wear out gradually. Most electric and gas ovens use either a capillary thermostat (a sensing tube filled with liquid) or an electronic temperature sensor (NTC thermistor). Gas ovens often use a combined thermostat and gas valve unit.
Signs Your Oven Thermostat Is Faulty
- Food consistently burns or undercooks at your usual settings
- Oven temperature measured with an oven thermometer differs from the dial setting by more than 20°C
- Oven heats up and then cools down repeatedly in a short cycle
- Oven runs continuously without cycling off
- Display shows temperature error codes (on electronic models)
Oven Thermostat Replacement Costs
| Repair type | Typical cost (parts & labour) |
|---|---|
| Capillary thermostat (electric oven) | £80 – £150 |
| NTC temperature sensor (fan oven) | £70 – £130 |
| Gas oven thermostat / valve unit | £100 – £180 |
| Diagnostic & calibration only | £40 – £80 |
The cost varies by brand and model. Parts for mainstream brands (Hotpoint, Beko, Indesit, Zanussi) are usually under £40 and readily available. Premium brands like Miele or AEG may have higher parts costs.
Is It Worth Repairing a Faulty Thermostat?
Almost always, yes. A thermostat replacement at £80 to £180 is far cheaper than a new oven. The repair is typically completed in a single visit and the engineer can confirm the oven is holding temperature correctly before they leave.
Gas Oven Thermostats — Gas Safe Engineers Only
If you have a gas oven, the thermostat is often integrated with the gas valve. Only Gas Safe registered engineers should work on gas components. Always check your engineer holds a valid Gas Safe registration before booking.
Get Free Thermostat Repair Quotes
Use the quote form on this site to describe your oven fault and postcode. We will match you with up to 3 vetted local engineers who will get back to you within 2 hours with no-obligation quotes. The service is completely free to use.