Category Archives: Electronic Repairs

Bypass tricity bendix SI455B oven timer

Hi, If you’re reading this then you have just realised that your oven won’t work because the timer on your oven is not working properly. I spent a year pondering this before I finally got around to fixing it.

My cooker model is the tricity bendix si455b, the timer model is the gosheim D-78559-b but the principle is the same for most timers.


Getting to your oven timer by flipping the hob

Getting to your oven timer by flipping the hob

Initially I realised that if you had the hob on for cooking from saucepans then hey presto the timer started working. From this I concluded that the reason the oven wouldn’t work was because of a faulty timer. Apparently it gets stuck on ‘auto’, if you can get it off ‘auto’ then the oven works. That’s when I started investigating how to bypass the timer.

First problem – getting to the timer

Not as bad as I imagined, is the quick answer. But do ensure that you have powered off the oven from the main fuse board. Safety first! After that….

The hob effectively hinges from the rear, you just have to release enough screws from the side, and upper front until you can flip up the hob. The key to success for my model was that there were 3 screws hiding behind some inch-wide trim down the side. After that it was a doddle.

Second problem – working out which wires to connect to bypass the timer

I used some pages from the web, first was a youtube video . I also found this page on the web which was simple yet helpful because it had virtually the same timer model as mine .

It was now more straight-forward than I first thought. It did help a lot to see the above two webpages and I did approach the problem in a very considered way. Never rushing until I had thought it through properly.

Third problem – Bypass top oven and main oven procedure

Take a picture of the timer before starting to ensure that failing everything, I could put it back together again, working or not working!

Original Assembly before bypass

Original photo of wire assembly. Note wire numbers to aid the instructions

Basically the job for my cooker was to:

  • Bypass the top oven (and grill) – Wires 1 (white) and Wires 2 (red) – combine and insulate!
  • Bypass the main oven- Wires 3 (yellow) and Wires 4 (orange) – combine and insulate!

I removed wires 1 and 2, cut the spade connectors off and combined them using a wiring block. I then insulated it with insulation tape. hey presto it worked.

Top oven - combine wires 1 and 2

Top oven – combine wires 1 and 2

Bypass main oven. I could have done exactly the same (combine wires 3 and 4) as for the top oven but instead I actually pulled the yellow (wire 3) completley off the timer and the oven switch. I then pushed the doubled orange (wire 4) straight onto the oven switch where the yellow wire had been leading to. I then could comepletely remove the yellow wire from the system. Same job as combining them really but a bit neater. Below is the picture of what the yellow (wire 3) and orange (wire 4) wires look like when combined. This was me testing before I went for the final finish.

Main oven timer - combine wires 3 and 4

Main oven timer – combine wires 3 and 4

The jobs was exactly the same for both oven types, however by thinking through I realised that for the main oven, all I needed to do was to remove the yellow wire completely and push the orange wire straight onto the oven switch (where the yellow wire was removed from the switch).

Finally a picture of the timer board without the oven and top oven wires, incase of confusion.

Timer board - after bypass. Only two wires left. Leave them alone

Timer board – after bypass. Only two wires left. Leave them alone

I hope this helps!