Bosch Range Error Code ER25

ER25 on a Bosch range indicates a false connection mains fault in the electric cooktop MTwisT control system. It means the cooktop control electronics have detected an anomaly in how the incoming mains power supply is being delivered or read. This is typically related to wiring at the terminal block or an issue with the supply voltage reaching the control module.

Yes, this error should be treated as a safety concern because it indicates a problem with the mains electrical supply to the cooktop control. A false connection or wiring fault in the mains supply can pose a risk of electrical damage to the appliance or, in severe cases, a shock or fire hazard. Avoid using the cooktop until the fault has been diagnosed and resolved by a qualified technician.

Repair costs vary depending on the root cause. If the issue is simply a loose or incorrectly seated wire at the terminal block, the labor cost for a service call is typically the primary expense, often ranging from $75 to $200 depending on your location. If the MTwisT control module requires replacement, parts and labor combined can range from $200 to $500 or more, depending on the specific model and part availability.

Basic checks such as verifying the circuit breaker and inspecting for obviously loose wires at the terminal block can be done by a knowledgeable DIYer, but working inside a range near mains wiring carries serious electrical shock risk. Because this fault directly involves the high-voltage supply connections, most homeowners should have a qualified appliance technician perform the diagnosis and repair. Do not use the cooktop while this fault is active.

Resetting the range by cycling the circuit breaker may temporarily clear the display, but the ER25 error will return if the underlying mains wiring or connection fault has not been corrected. A reset does not fix a loose terminal, incorrect wiring, or a faulty control module. The root cause must be identified and repaired for the fault to be permanently resolved.