De Dietrich Oven Trips Rcd Only When Very Hot ! Please Help !

[DIY]

Hi Everyone 

I bought a De Dietrich 795B oven 5 years ago. It worked well until last year.

It trips RCD when It reaches the set temperature or when turned off, or when the door is opened (which turns off the oven)

But the strange thing is that it will trips RCD only when it runs for a while, at least 15 minutes - when it's very hot. If I set low temperature like 100c it works fine since it doesn't have time to get very hot, i think.

For example, if I set it at 250c from the beginning, it will take about 20 minutes to get to 250c and thermostat will cut and RCD tripped at the same time. Or If I turn it off or open the door before it reach the set temperature but after 15minutes it will also trips RCD. If I open it after just 10 minutes, it won't trips the RCD since the heating element is not glowing red hot.

what I have done so far is :

-changing RCD 

-testing the heating element - looks fine, no sign of problem, continuity test ok, 17 ohms

(I connected the oven  directly from the breaker after RCD - no other appliances attach to the breaker)

- I removed the back cover and let it run for 1 hour for the set temperature of 250c (which it will never reach coz the  cover opened), it won't trip the RCD. (which means it about how hot the element is, not how long it runs.)

I think it has to do with the heating element when it's really hot, and suddenly turned of by thermostat or on/off button or  the door.

But with my limited knowledge, I don't know how to explain the situation. I don't know what to do next.  It's really frustrating. 

Please help me

 

[sparkytim]

Oven elements may well become leaky with age and trip RCDs when hot.  Also RCDs can trip on switch offs, especially with double pole switching when the N disconnects before the L. 

 

[binky]

needs new element

 

[Andy™]

+1. needs new element

 

[DIY]

Oven elements may well become leaky with age and trip RCDs when hot.  Also RCDs can trip on switch offs, especially with double pole switching when the N disconnects before the L. 

First of all, thank you everyone for the answers. You people are very quick, indeed !!

I will try to change the element and see how it goes.

By the way, as sparkytim explained, It's still not clear to me, if the element trips RCD when hot, why it doesn't trip any time, why it trips when switching off ?

So it's like Hot element + Double Pole switching ? If that's the case, may be the double pole switching is the main problem ?

Is there anything I could do with the double pole switching ?

 

[binky]

its the expansion of the element causing movement of the insulation and allowing shorting out. Had same problem years ago, started as only tripped occasionally at full temp, then progressed to every time at full temp, but could be nursed along at lower temp, then when that stopped working I finally got around to changing the element.

 

[Andy™]

try cpc.co.uk for an element

 

[Technician]

When you get the element you may find that the supplier

will not supply the fastenings for the element at the back

of the oven.  I had this a little while back and I had to find

the nuts and thankfully I had a local hardware man who

lent me some samples.  The screws/nuts are usually 4 mm

bright zinc or stainless but look out for this little snag.

 

[DIY]

its the expansion of the element causing movement of the insulation and allowing shorting out. Had same problem years ago, started as only tripped occasionally at full temp, then progressed to every time at full temp, but could be nursed along at lower temp, then when that stopped working I finally got around to changing the element.

Hi Binky

In your case did it trip RCD when you opened the door or turned it off after runnning for a while or not ?

I'm just wondering why it has to trip right when I open the door/turn off/ or when thermostat cuts when reaching set temperature !! ??  (@_@)"

Thank you for all answers.

 

[Andy™]

Hi Binky

In your case did it trip RCD when you opened the door or turned it off after runnning for a while or not ?

I'm just wondering why it has to trip right when I open the door/turn off/ or when thermostat cuts when reaching set temperature !! ??  (@_@)"

Thank you for all answers.

probably because opening / closing the door causes slight vibration, enough for the faulty element to short out at that point and cause the RCD to trip

 

[DIY]

probably because opening / closing the door causes slight vibration, enough for the faulty element to short out at that point and cause the RCD to trip

 Most of the test is done by turning it off and it doesn't vibrate anything at all coz it's digital button .. :-(

 

[ProDave]

Elements are cheap. Just buy a new one and change it.

 

[binky]

Hi Binky

In your case did it trip RCD when you opened the door or turned it off after runnning for a while or not ?

I'm just wondering why it has to trip right when I open the door/turn off/ or when thermostat cuts when reaching set temperature !! ??  (@_@)"

Thank you for all answers.

sudden change in temp, including thermostat turning off. Your element is 'on the edge' just needs a slight push. Don't fret over it get a new element.

 

[DIY]

Thank you very much everyone.

I will let you know the result when it's done

 

[DIY]

IT WORKS !!!

Problem solved !!

I've got the new heating element today. After replacing, it's like I've got a new oven.

I can set to 250 degree right away, no problem at all. WOW !!

I'm very happy to get this done myself

And again, thank you very much everyone for your advice. 

You people have been very helpful, I'm really appreciated.

 

[kme]

Another satisfied customer...........

magic, guys Give yourselves a pat on the back ( apart from `pache - I think Ermintrude did that for him, earlier) :slap