You follow every recipe exactly. Your timer is correct. But your cakes are burnt on top and raw in the middle. Your roast chicken comes out dry. The problem isn't your cooking — it's your oven's thermostat.

How an Oven Thermostat Works (And How It Fails)

The thermostat senses oven temperature and tells the heating element or gas valve when to turn on and off. Over years of heating and cooling cycles, the sensor drifts. A thermostat that once turned off at 180°C now lets the oven reach 220°C before cutting power.

The KSh 500 Test: Buy an Oven Thermometer

Buy a standalone oven thermometer (KSh 500-1,000 at any kitchen shop). Place it inside your oven. Set the oven to 180°C. Wait 15 minutes. Read the thermometer. If it reads above 200°C or below 160°C, your thermostat is inaccurate.

Calibration vs Replacement

Some ovens can be calibrated: Look for a small screw behind the thermostat knob. Turning it adjusts the temperature offset. This works for analog ovens (with dials). Digital ovens require thermostat replacement.

Replacement Cost Breakdown

Thermostat sensor: KSh 1,500-3,000. Control board (if sensor integrated): KSh 4,000-8,000. Labor: KSh 1,500-2,500. Total: KSh 3,000-10,500.

"My digital Defy oven was off by 40°C. Calibration wasn't possible. Repair Ready replaced the sensor for KSh 3,500 total. Now my cakes come out perfectly." — Mary, Kilimani

📞 Call 0707 790 099 if your oven thermometer shows a large temperature discrepancy.