August 15, 2025 
My Neff B45E74N3GB/04 Oven is approximately 11 years old and has had very little use throughout its life. When the tripping started to occur, some 3 to 4 year ago, we stopped using it for a few months and when we started to re-use it, it was fine for a short period of time and then started tripping again. This remains to be a persistent, intermittent problem and is so frustrating. When Circotherm Intensive, (our main selection for cooking frozen foodstuffs), is selected, the oven does heat up. Sometimes, whilst heating up to the required temperature it will trip the RCD, (the tripping temperature appears to be random, not specific). If the oven does reach the required temperature, it tends to trip some 5 to 10 minutes later, whilst cooking. If I reset the RCD and switch the oven back on, it will continue to reach the required temperature and indeed cook without further issue. On other occasions, it doesn’t trip at all from start to finish. I have uninstalled the oven from its housing and taken off the back-plate and cannot find any evidence of chafing cables, broken cables nor burning. It is as if new. The only thing I can see is what I would call ‘flaking paint’ from the metal cradle that holds the bottom, (baking), element lying on the insulation at the bottom of the oven. I have picked up a lot from watching your superb videos on youtube and appreciate that the issue could be a number of things. I have checked the resistance of the fan element – a constant 25 ohms. I have also checked the resistance of the bottom element – a constant 42 ohms. If it is one of these elements, I would have no problem removing the fan element but cannot see, at all, how to remove the bottom element. It is definitely the oven that is tripping RCD. Please help.
Dale Cowey
Hi Dale sorry to hear about the problem with your Neff B45E74N3GB/04 Oven,
Your circuit breaker is tripping due to an earth leakage fault in the oven. Since I can’t verify your meter readings, the best approach is to physically test the components. The heating elements are the most likely cause.
You need to disconnect all three elements—the top grill, bottom base, and fan oven element. Take photos of the wiring first. If the oven stops tripping after they are disconnected, you’ve found the problem area. If it still trips, the elements are not the cause. In that case, you should inspect the selector switch, fan motors, and the main connection block for damage.
I’ve recently published a video series for this issue. It’s not the same make but the principle is the same. You can watch them via this link:
Unfortunately, the manufacturer does not release technical wiring diagrams and workshop manual, but I have provided an exploded view and some videos to help you identify the parts.
If you need the fan oven element, base element or any other spare parts, you can always visit our shop page.
In the video, I mentioned about 5 common problems.;
- Oven will not heat because the element is faulty.
- Oven won’t heat because timer on manual.
- Oven won’t heat because of a fault with thermostat or selector switch.
- Oven not cooking evenly (one element faulty or fan not working correctly).
- Oven not reaching temperature normally an element but possible fan motor.
Coomon Problems with Electrical Ovens
- The oven will not turn on
The first thing you need to check is that the oven timer is not on auto if it is, turn it on to manual.
- No Heat in Oven
If the fan is running and the thermostat light comes on but you get no heat (or just the thermostat light on in non-fan ovens and cookers) then the probability is that the fan element or oven elements have failed.
- Electricity trips (Rcd) when I turn the oven on or grill
This is normally an element that has gone to earth, This is a well-known fault with electric ovens, the insulation breaks down in the elements and trips the RCD , best way is to stick a meter on each element and check that they have not got earth leaks on them. But this can also be a wiring fault.
- The grill element doesn’t work
This would usually indicate that the grill element is faulty. Check these: Grill element, Oven changeover switch, Overheat thermostat, Main oven thermostat, if used to regulate the grill temperature.
- The oven fan is not working or spinning correctly (slow) or is noisy
The fan motor may need to be replaced see video on this also the cooling fan motor can cause same problems.
- The oven overheats and burns everything
Normally this is a simple thermostat failure which would manifest itself as this symptom.
- The oven or cooker cuts out after it’s been on for a while
This is an overheating problem which can be caused by the fan motor or main oven thermostat or a faulty safety thermostat that will be causing the problem. It can also be caused by a failure of the cooling fan, where fitted, but usually these go noisy before failing, Safety thermostats are used to prevent the oven or cooker overheating and will shut the oven down.
If you need any further assistance please feel free to contact me. all the best Paul.
Paul Charmbury
Appliances Engineer
Video to help you with your Neff B45E74N3GB/04 Oven
Neff B45E74N3GB/04 Oven Exploded View of the Parts
Neff B45E74N3GB/04 Oven Exploded View of the Parts