Tripping oven

Bendy_House

Danny30 said:

I mentioned if it could be another element and they discounted that option.

I'm trying to work out why they'd say that - it doesn't make sense to me. There are TWO elements in that top oven, and you've replaced one. And it DOES happen (occasionally) that a new element also leaks; a slight knock or bend in the element body can break the insulation surrounding the central heating wire, allowing it to get close enough to the outer shield for it to leak the required ~30mA, or even less.

Your call. I've suggested how to discount it being the elements.

Replacing the oven control isn't technically difficult - it's usually largely a matter of pulling off and replacing lots of spade connectors - but the two most awkward parts are running the thermostat capillary tube (don't bend it excessively) and possibly getting access to the switch's mounting screws/nuts.

Talking of 'nuts', you would be if you replaced the switch without first eliminating the elements as being the cause.

Discounting the elements is a no-cost task. Other than time. And life if you're not careful. So, potentially quite costly, then.

Yup - the wit is free... :-( 

EssexExile

Section62 said:

Danny30 said:

Thank you very much for your detailed response. I just called up Belling a few minutes ago and told them the symptoms as described above and they said it would be either the element on the top, the cooling fan or the top oven switch. As I changed the element and I am pretty sure the cooling fan is working (double check when I get home) it must be the top switch then. How complicated is that to change?

Or the/an element.  Don't fall into the trap of "I've changed this, so it can't be that".  If you follow that route you can end up paying more for parts than it would cost for a pro to do the repair.

It is probably significant that switching to oven causes immediate tripping, whereas the grill setting causes a delayed tripping.  If you turn the grill back on straight away (while the element is still hot) does it trip the CU out again after the same amount of time, or faster/slower than the first time?

New elements tripping the power used to be quite common. It was usually cured by heating the element which dries it out. The repair men have a way of doing that.

Danny30

Section62 said:

Danny30 said:

Thank you very much for your detailed response. I just called up Belling a few minutes ago and told them the symptoms as described above and they said it would be either the element on the top, the cooling fan or the top oven switch. As I changed the element and I am pretty sure the cooling fan is working (double check when I get home) it must be the top switch then. How complicated is that to change?

Or the/an element.  Don't fall into the trap of "I've changed this, so it can't be that".  If you follow that route you can end up paying more for parts than it would cost for a pro to do the repair.

It is probably significant that switching to oven causes immediate tripping, whereas the grill setting causes a delayed tripping.  If you turn the grill back on straight away (while the element is still hot) does it trip the CU out again after the same amount of time, or faster/slower than the first time?

So I did as you said. I heated the upper oven grill and then it cut off when hot. I then flicked the RCD back on and selected the grill again and it tripped the RCD again. 

Section62

Danny30 said:

Section62 said:

Danny30 said:

Thank you very much for your detailed response. I just called up Belling a few minutes ago and told them the symptoms as described above and they said it would be either the element on the top, the cooling fan or the top oven switch. As I changed the element and I am pretty sure the cooling fan is working (double check when I get home) it must be the top switch then. How complicated is that to change?

Or the/an element.  Don't fall into the trap of "I've changed this, so it can't be that".  If you follow that route you can end up paying more for parts than it would cost for a pro to do the repair.

It is probably significant that switching to oven causes immediate tripping, whereas the grill setting causes a delayed tripping.  If you turn the grill back on straight away (while the element is still hot) does it trip the CU out again after the same amount of time, or faster/slower than the first time?

So I did as you said. I heated the upper oven grill and then it cut off when hot. I then flicked the RCD back on and selected the grill again and it tripped the RCD again. 

Immediately, no delay the second time?

Danny30

Section62 said:

Danny30 said:

Section62 said:

Danny30 said:

Thank you very much for your detailed response. I just called up Belling a few minutes ago and told them the symptoms as described above and they said it would be either the element on the top, the cooling fan or the top oven switch. As I changed the element and I am pretty sure the cooling fan is working (double check when I get home) it must be the top switch then. How complicated is that to change?

Or the/an element.  Don't fall into the trap of "I've changed this, so it can't be that".  If you follow that route you can end up paying more for parts than it would cost for a pro to do the repair.

It is probably significant that switching to oven causes immediate tripping, whereas the grill setting causes a delayed tripping.  If you turn the grill back on straight away (while the element is still hot) does it trip the CU out again after the same amount of time, or faster/slower than the first time?

So I did as you said. I heated the upper oven grill and then it cut off when hot. I then flicked the RCD back on and selected the grill again and it tripped the RCD again. 

Immediately, no delay the second time?

Yes, immediately tripped the RCD

Section62

Danny30 said:

Section62 said:

Danny30 said:

So I did as you said. I heated the upper oven grill and then it cut off when hot. I then flicked the RCD back on and selected the grill again and it tripped the RCD again. 

Immediately, no delay the second time?

Yes, immediately tripped the RCD

As EssexExile says, damp is one reason why an element would trip.  But if the element trips the power faster when it is hot than cold it tends to point to something other than damp - possibly a part that is tripping the power when it reaches a certain temperature.

Although Bendy makes a good point about the oven having a second element at the bottom, I doubt (but could be wrong) this is used in 'grill' mode.  Therefore if the oven trips the power in grill mode as well, it points away from the second element being the cause of the fault. I think this is why Belling said the top element (only).

I think given the oven is only two years old it may be worth getting a professional to take a look, but it is up to you whether to go with that option, or use the money towards a replacement oven.

Bendy_House

As you say, S62.

I recall it driving me completely bonkers when it was my oven that did this - it didn't seem to make normal electrical sense!

But...Danny, when eliminating the elements is soooo easy to do...

Sigh, I'll shut up now. 

Catnip2015

Bendy_House said:

Danny30 said:

Hi Bendy, the oven trips as soon as I move the upper oven dial onto the oven symbol (See highlight on image below) . It doesn't trip when turning up the thermostat. I was also able to run the upper oven grill for a few mins before it tripped (which used the same element I replaced), so the only thing that trips it straight away is turning the dial onto the oven symbol.

I changed the element on the top of the upper oven which I managed to get for a good price so thought it was worth a try, but it didn't help unfortunately.

As S62 says, some of these elements are cheap for a reason - I have also found that to my cost. The last time my main oven element went - only a few months after fitting a cheapy - I went 'reputable' supplier. And it was still very good value, and still going strong.

Ok, I wasn't hoping for your answer about what setting makes the RCD trip, until I recalled - with a horrible neck-tingle - that this was the very symptom that drove me nuts, and made me start to dismantle the oven! With mine, I now recall the thermostat didn't need turning up either, so my hapless brain convinced itself it had to be another component that was common to all the oven settings, so my suspicions landed on the cooling fan. I disconnected that and... it kept tripping.

I sought help on a leccy forum, and all the replies said the same - an oven element. I then disconnected all the elements, taping up (and labelling!) the loose terminals, and tried the oven on each setting. No tripping. Replaced each element in turn, until 'pop'. Looked closely at the miscreant element, and noticed a bulge on the side...

Danny, since you are clearly DIYish enough to swap an oven element, and so far without 'cuting yourself, I really think this is worth a go. Since no heat will be involved, it'll be perfectly fine if you tape up the spade terminals and position them where they won't move or touch anything whilst you briefly turn the oven on each time to test. The ONE VERY POSSIBLE danger is that you become COMPLACENT when doing this, because there will be REPEATED power-isolation and power-on sequences each time you reconnect an element, and that's when mistakes happen.

So, BIG MANTRA: OFF at the CU, OFF at the wallplate, TEST with, er, a tester.

Oven oot, back offski, remove each element's spades, tape them up, label them, tape them to a nearby thingy to keep them from moving. Repeat for all three top oven elements.

ON at CU, ON at w/p, turn on t'oven. If it doesn't go 'pop', then holler loudly and do a wee dance - AFTER turning it all off again.

POWER OFF x 2, and replace one element's connections (say the bottom element, since you haven't replaced that one). 

Rinse, repeat, but don't get in a lather.

A bottom element is around £25, and you'll feel really good if this sorts it. Yes, it could be down to another issue, but that would be very unlikely in an oven, and it's sooo easy to eliminate the obvious - as long as you do so safely.

Thank you so much for this detailed explanation for troubleshooting.
Our oven started tripping the RCD and a heating element was suspected by a local electrician.
Followed your steps and managed to determine that it was the grill element in our oven that was the culprit.
Replaced it and now we are back in business