The underside of a stainless wall-mount range hood with its filters in place and its lights on, the burners below switched off and bare, a faint shimmer of warm air in the frame.

Bosch under-cabinet fan key flashing slowly: the heat sensor has the blower

The thermostat reacts to excessive heat above the cooking surface.

(844) 398-3217

Mon–Sat, 8am–8pm

  • Heat and grease sensors
  • Range hood heat sensor repair
  • Source: Bosch

Book a visit

Three short steps, about a minute.

or call (844) 398-3217

What Fan key backlight flashes slowly
actually means.

The thermostat reacts to excessive heat above the cooking surface. With the blower off it starts it at high; with the blower on low it steps up to high. While it is in charge, the fan key flashes slowly, the speed cannot be changed, and the control panel cannot turn the hood off, only the main power switch can.

Bosch range hood display · also shown as Heat sensor active

What to do when Fan key backlight flashes slowly shows on the range hood

Before you book,
in this order.

Each step comes from Bosch's own guidance for Fan key backlight flashes slowly on its range hoods. Follow it to the end: the last card says whether this is a visit.

01

Leave the blower running and lower the heat under the pans.

02

Wait for the temperature to fall; the blower returns to its earlier setting on its own.

03

If you must stop the blower, use the hood's main power switch as the manual describes.

04

Book a visit if the heat sensor triggers with little heat below or never lets go.

Still there?

It usually turns into range hood heat sensor repair. Book with the code and the model number.

What not to do

This is not the automatic mode you switch on with its key, which adjusts speed to cooking heat and turns the fan off afterward. A key flashing only at switch-off is the filter reminder, not the sensor.

What you may
notice with it.

The range hood problems Fan key backlight flashes slowly tends to arrive with. Answer these at the range hood before anyone is booked.

All problems

Where Fan key backlight flashes slowly usually leads

Range hood heat sensor repair.

Heat sensor or thermostat disc and its lead · low.

In Bosch's own words

When the heat sensor is activated, the fan key backlight
Bosch Undercabinet Hood User Manual (DUH and DUHP models) Bosch Undercabinet Hood User Manual (DUH and DUHP models) Bosch Undercabinet Hood User Manual (DUH and DUHP models)

Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. Bosch under-cabinet hoods DUH30253UC, DUH56353UC, DUH80553UC, DUH86553UC and pull-out models DUHP0853UC, DUHP6853UC.

Bosch Fan key backlight flashes slowly range hood repair,
where we come out.

The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered.

All service areas
A family cooking together under a stainless range hood in a bright kitchen.
For the heart of your home.

Questions
about Fan key backlight flashes slowly.

Can I clear Fan key backlight flashes slowly myself?
Leave the blower running and lower the heat under the pans. If it comes back, it needs a visit.
Why won't my Bosch under-cabinet hood turn off from its buttons?
If the fan key is flashing slowly, the heat sensor started the blower and the panel cannot override it. It shuts down once the heat drops, or you can use the main power switch.
What sets off the heat sensor on a Bosch under-cabinet hood?
Excessive heat rising from the cooking surface, such as several high burners or a wide pan searing directly below.
Is a Bosch hood that runs on high by itself a sign of trouble?
Not when the fan key is flashing and the burners are hot; that is the sensor at work. With a cold cooking surface, it points to a sensor or control that needs testing.

Back to your everyday

Still showing Fan key backlight flashes slowly?

Three things make the booking useful: the letters or blink pattern exactly as they showed, the full model number from the label behind the filters, and whether the fan still moves air on every speed. With those, the technician arrives with half the answer already worked out.

(844) 398-3217 Schedule a repair