Bosch oven HBN 1312.0

SOURCE: Bosch HBN 455 Oven Cooling-Fan Issue

Our HBN655 had similar issues- the upper cooling fan would cycle on and off on a relatively quick duty cycle until the whole mess cooled off enough and it shut off.
My workaround is to turn the temperature dial off but leave the oven function dial on to BAKE. This seems to force the fan to stay on; then we shut it off a while later and avoid the annoying fan cycling.
(note- 2 years ago, our fan became intermittent, varying speed, etc... for about 2 months before it quit entirely. When that happened, the oven started to heat then the thermal cutout kicked in and the oven shut down entirely. We ended up replacing the fan and that fixed the bug... except now it's starting to act up again...)
(also note- the racks on this beast have a faulty design. if you have a heavy casserole and slide the rack out all the way, it tends push the sidewalls apart and the rack drops. I spoke with Bosch about this and they sent me new racks, no charge... so they know there's a problem. But the new racks don't fix the bug; they just make it harder to reproduce. I have actually had one rack fall with 2 piping hot casseroles on it. Fortunately no one was hurt.)

SOURCE: bosch electric single oven (hbn 4305)

hi there have you cheked that your timer is not set to auto function

SOURCE: Bosch oven not heating to temp

Dear customer,
i recommend u to try the following routine to sort out this problem

SOURCE: INSTRUCTION MANUAL

you can obtain the instruction manual for this directly from the bosch web site free of charge if it is not listed there try the BSH Home appliances ltd site they are the manufacturers repair service in the UK

SOURCE: My Bosch HBN 5605 .0B oven has a 15-20 degree

I detected a similar problem following the sudden appearance of Err1 in the display. (Oven 4-5 years old, and the grill element failed when it was 3-4 years old). This indicated a temperature sensor problem. My local dealer came with his Thermocouple and confirmed an "under temperature" reading on the standard and baking settings. I agree that the fan setting is probably OK. He replaced the sensor. I monitored the situation for a while and was not happy because an under temperature could be quite dangerous when cooking certain foods, and also causes problems when baking bread.

The location of the oven sensor is also a problem because it is at the top right by the grill which also serves as the top heat source.

I had corresponded with Bosch about this and their response was, frankly, less than satisfactory. In the end I decided to call out their engineer (cost £85-ish) who wired my oven up to his computer. In the end he said that the oven was working as it should be (despite it taking a very long time to actually reach the target temperature of 200C.

In my view of I want 200C, then I should get 200C, not an approximation.

Interestingly the secret info (not in the manual) is that the temperature bar readout does not indicate that it has reached the actual temperature, but may be 90% of the temperature (so if you want 200C you get 180C.

An unsatisfactory solution is to get an oven temperature of the meat probe type and put that in the oven, then you will get a more accurate reading of the temperature. You would need one that goes above 200C (my first one only goes to 200 but I have found another that goes to 250C). Mine is by CDN model DTP482, any good cook shop should stock this.

Andrew Finch