Whether the oven won't heat at all, only the grill works, or it stopped after a power cut, here's what usually causes it.
Quick answer: The most common causes are a failed heating element (bake, grill or fan element), a faulty thermostat, a failed selector switch or timer, or a failed fan motor in fan ovens. Many built-in ovens also won't heat until the clock is set after a power outage, so check that first.
| Symptom | Likely cause | First check |
|---|---|---|
| Oven not heating at all | Clock not set; element; thermostat; selector switch; thermal cut-out | Set the clock, check the breaker |
| Only the grill works | Bake (bottom) element or selector switch | Look for a break or blister on the element |
| Fan oven cooks unevenly | Fan element or fan motor | Check whether the fan turns |
| Oven too hot or burning food | Thermostat or temperature sensor | Compare with an oven thermometer |
| Trips the power when switched on | Shorted element or damaged wiring | Don't keep resetting. Book a technician. |
Our technicians come to you anywhere in Gauteng. The call-out is a flat R350 to diagnose the fault (waived if you go ahead with the repair), you get a fixed price before any work starts, and every repair has a 6-month guarantee.
If a gas burner clicks but won't light, the igniter or spark switch may be faulty, or the burner may be wet or not seated properly. If a flame goes out when you let go of the knob, the thermocouple (flame safety device) has failed. That's a safety part and must be replaced, not bypassed. If you smell gas, turn off the supply, open windows and don't use any switches.
Ovens are usually worth repairing, because most faults are elements, thermostats and switches. Built-in ovens from Bosch, Siemens, Smeg, Defy and Elba are almost always worth repairing, because a replacement also has to fit your existing cabinet.
Call or WhatsApp 072 686 0472. Every job starts with a flat R350 diagnostic call-out across Johannesburg, Pretoria and the East Rand.
By Absolute Repairs · Updated October 2026
This Rational (Vulcan) COS 20 combi oven in a Pretoria restaurant would run for a while and then trip the power, which is a serious problem in the middle of a service. When we opened up the side panel and diagnosed it, we found that one of the fan motors was partly seized. A fan motor that is starting to seize turns stiffly, so it has to work much harder and draws far more current than normal. As it heats up, that extra current builds until it trips the breaker, which is why the oven worked for a while before cutting out. We replaced the fan motor and ran the oven up to temperature to check it stayed on without tripping. The kitchen was back in full service. Tip: a commercial oven that trips only after it has been running for a while usually has a part that is drawing too much current as it heats up, such as a tight fan motor or a failing element. If the fan sounds rougher or louder than usual, get it checked before it seizes completely.
The customer phoned to say the oven was battling to reach temperature, and asked us to replace the thermostat. We recommended an assessment first, because several parts cause the same symptom. Our technician found the bottom (bake) element wasn't coming on, but the element and the thermostat both tested perfectly. The real fault was the oven's function selector switch: one of its terminals had burnt, so power never reached the bottom element. We replaced the selector switch and the oven heated up properly again. Diagnosing first saved the customer the cost of a thermostat they didn't need.
Yes. The selector switch sends power to the right elements for the function you choose. If its contacts burn, an element such as the bottom (bake) element gets no power, so the oven struggles to reach temperature even though the element and thermostat are fine.
Many built-in ovens need the clock to be set before they'll heat after a power cut. If it still won't heat after setting the time, a surge may have damaged the timer, control board or an element.
Usually the bake (bottom) element has failed, or the selector switch isn't sending power to it.
Every oven repair starts with a flat R350 call-out fee, which covers travel, diagnosis and a written quote. Elements and switches are the most common and affordable repairs.
Yes. We repair gas hobs and cookers, including igniters, spark switches, burners and thermocouples.
Tell us your suburb, the brand and model, and the fault. Standard R350 diagnostic call-out.
📞 Call 072 686 0472 💬 WhatsApp UsOr email info@absoluterepairs.co.za
Tell us what's broken and where you are. We'll call you back to confirm a time, usually the same day.
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