Temperatures Run Hot, Cold or Never Arrive: Bosch Oven E027

What E027 means

Cakes burn on the outside, roasts take forever, or the preheat tone never sounds, and E027 may be behind it. The oven's temperature sensor is how the control knows what the cavity is doing. When that reading drifts or goes wrong, the oven cannot hold the number you set, so it overshoots, undershoots, or keeps heating without ever arriving.

Common causes of E027

Sensor probe (an RTD) that has failed or drifts out of accuracy
Damaged wiring leading to the sensor
A sensor that was put back in the wrong position during an earlier repair

✓ One safe check you can try

1. Do not try to test the sensor yourself. Its resistance is measured with a multimeter on an oven that is fully de-energized, and that is technician work. 2. What you can do is use a separate oven thermometer for a day and note how far the real temperature is from the set one. 3. Share that gap when you book.

! Why to stop there

Checking a sensor requires removing power and opening the cavity, near heating elements and live wiring.
A wrong reading can come from the sensor, its wire or its position, and guessing wastes parts.
A sensor that is bent or misplaced during a DIY attempt can make the temperature error worse.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

→Same appliance

Other Oven codes

E223Lower Probe Reads Colder Than Allowed (Bosch Oven E223) E226Bosch Oven E226 After the Lower Door Latch Signal Is Lost E309Control Module Failed Its Program Memory Check: Bosch Oven E309 E310Bosch Oven E310 Signals a Settings Memory Failure on the Control Module E312The Control Board's Own Heat Sensor Died (Bosch Oven E312) E314Bosch Oven E314 When the Cancel or Off Key Reads Stuck E414Off Key Failure Logged Behind the Scenes, Bosch Oven E414 E201Bosch Oven E201 on a Double Wall Model, Lower Cavity Sensor Reads Open

E027E027 questions

Does E027 mean my oven is unsafe?

Not on its own, but an oven that cannot read its own temperature can overheat or underheat food. We recommend limited use until the sensor is checked, especially for long roasts.

Is the sensor an expensive part?

Usually it is a modest part with a reasonable labor cost. We confirm the cause first and give you a written price before we replace anything.

Can the oven just be recalibrated?

If the sensor is only slightly off, a calibration offset may help. If it has failed or is wired poorly, replacement is the lasting fix, and we explain which applies.