Bosch Dryer Error Code E:15

The E:15 error code on a Bosch dryer indicates a fault in the heating circuit, specifically that the dryer has detected no measurable temperature rise after a drying program has been initiated. The control board monitors temperature progression during the early phase of a cycle, and when the expected heat increase fails to occur within a defined window, the fault is logged and the cycle is interrupted. This code applies only to non-US and non-CN market models, as those variants use different heating configurations.

The heating circuit in these dryers consists of several components working in series: the main heating element, one or more bimetal thermal cutout switches, wiring connections, and the control board relay that energizes the circuit. A break anywhere in this series path will prevent current from reaching the element, resulting in no heat production. The bimetal switch is a common failure point, as it opens permanently when exposed to excessive temperatures and does not self-reset, cutting power to the heater as a safety measure.

Diagnosis should begin with a visual inspection of the heater circuit wiring for signs of burning, corrosion, or disconnected terminals. Continuity testing of the heating element and each bimetal switch with a multimeter will confirm whether an open circuit exists in any of these components. A failed bimetal switch will show no continuity and must be replaced. A burned-out heating element will similarly show an open reading and requires replacement before the dryer will produce heat again.