Zanussi hob very hot after testing!

[NotVeryHandy]

Hi all,

I'm not a qualified electrician bit I have bit the bullet and tried to install my Zanussi hob.

I purchased a 45a cooker outlet plate and removed the cable from the old cooker into the outlet plate. The cable is 6mm t&e which comes from the cooker switch as installed when I had a re-wire.

I then installed a 6mm t&e cable from the outlet plate to the hob. All live, nuetral and earth connections are fine tight and secure.

As per the manufactuers instructions I placed pans with water on each hob and set the knobs to maximum (6). They started to boil but I thought the slight smoke underneath does not seem right.

Even now 20 minutes or so after switching it off the actual metal base of the hob is red hot.

The circuit did not trip. The 45a outlet plate is intact. The 6mm cable from the outlet plate to the cooker has not melted in any way.

The only check I have not made is the condition of the cable at the hob connection point. Apart from melting the plastic should I be expecting anything else?

Something is seriously not right, apart from me calling in someone qualified, so any suggestions please?

Let me know if further information is required.

TIA.
NotVeryHandy

 

[JohnW2]

Even now 20 minutes or so after switching it off the actual metal base of the hob is red hot.

If that is even remotely close to be (literally) true, it certainly doesn't sound right - but I rather doubt that it is anhything to do with the electrical cables/connections/wiring. I think you probably need to speak to the manufacturer or supplier.

The only check I have not made is the condition of the cable at the hob connection point. Apart from melting the plastic should I be expecting anything else?

Are any of the accessible cables getting hot?

Kind Regards, John

 

[Jackrae]

Turn off cooker supply breaker and look at meter to determine how fast it is going round or flashing. Now turn on cooker supply breaker and without turning on any of hob plates again look at meter. If it's the same speed then you are looking at residual heat, if it's faster then at least one of the devices is on when it shouldn't be (make sure fridge or freezer isn't influencing meter rate.)

 

[JohnW2]

Turn off cooker supply breaker and look at meter to determine how fast it is going round or flashing. Now turn on cooker supply breaker and without turning on any of hob plates again look at meter. If it's the same speed then you are looking at residual heat, if it's faster then at least one of the devices is on when it shouldn't be ...

I don't think the OP is suggesting that the hob is continuing to consume electricity when all the plates are switched off but, rather, that it gets so hot ('smoke') when they are all switched on that it is still very hot 20 mins later (i.e. as you say, 'residual heat'). I imagine that if (s)he waited long enough, it would cool down. However, it certainly sounds as if something may well be wrong with hob.

Kind Regards, John

 

[Taylortwocities]

Many hobs like this have several options for their supply voltage/number of phases, etc.
My first thought is that the OP should make absolutely certain that any power straps are properly in place.

 

[JohnW2]

Many hobs like this have several options for their supply voltage/number of phases, etc. My first thought is that the OP should make absolutely certain that any power straps are properly in place.

Good point. I wonder if the OP could provide us with a photo of where the connections are made to the hob?

Kind Regards, John

 

[NotVeryHandy]

Thank you for your help so far all. I will post some pictures tomorrow morning.

I've checked the hob and there is no deterioration in the cable or the connecting block at all.

I need to test the heat of the cable between the 45a box and the hob if I read correctly?

There is no increase in speed on the meter when the cooker switch is turned on. But there is a increase in speed when i turn only one ring into notch 1.

 

[JohnW2]

Thank you for your help so far all. I will post some pictures tomorrow morning.

That would be helpful. In case the problem is related to TTC's comment, I would suggest that you don't try using the hob until we've seen those pics. Your fiundings regarding the meter are as I would have expected.

In the meantime, can you tell us the model number of this Zanussi hob?

Kind Regards, John

 

[Iggifer]

Some smoke is to be expected from any new hob, no? All the new ones I've ever turned on have had some layer of presumably cleaning/polishing chemical that has burnt off on first run.

It would be useful to know if 'red hot' means actually still glowing, or just hot. There's a big difference there in terms of what's going on. Red hot meaning red hot means it's still drawing power, red hot meaning it's just hot to the touch could just mean it retains it's heat really well. One of the reasons I hate ceramic hobs, once your pan boils over, you're not putting it back on that same ring for a good 10 minutes at least

 

[JohnW2]

It would be useful to know if 'red hot' means actually still glowing, or just hot.

Indeed - but the OP said that it was the "the actual metal base of the hob" that was "red hot" 20 minutes after turning the hotplate off - and if I'm interpreting that correctly, that should surely never be desperately hot, let alone "red hot", even when the hotplates are all on - and, even more 'let alone', 20 mins after the plates have been turned off.

Kind Regards, John

 

[Iggifer]

True, if we're talking about a glass top hob with a shiny steel underside, then that defintely should not get hot, but as has been mentioned, I don't think that's a wiring issue, that's an insulation issue in the hob - no insulation = red hot base (and presumably internal wiring

 

[Echo the husky]

If it is a 'solid' element and a stainless steel hob, these get dangerously hot if you leave them all set to 6, often to the point where the rings are starting to glow a dull red and the stainless steel near the rings starts to discolour. The metal to metal contact transfers the heat to the entire unit making it very hot indeed. Of all the types of hob these are my least favourite, they have limited control and stay dangerously hot for ages after they are switched off. They also give no indication that they are on.

 

[NotVeryHandy]

 

[NotVeryHandy]

I've included a picture of the cover plate showing the various wiring options. These are post testing so there is no melting to the cable after what I originally wrote. As can be seen, the live terminals in the hob are connected by the metal u shape objects.

 

[NotVeryHandy]

So my over riding question is, using the 45a outlet plate, 6mm t&e plate to hob and the wiring I have used at the hob........have I wired this correctly?