Induction Hob Issues

[J_Ashley]

I wondered whether anyone more electrically minded than myself could shed some light on induction hob issues I’m having. We installed a new induction hob and bought appropriate magnetic pans, although the performance whilst perfectly functional has been disappointing.

To give some numbers; the hob is a 7.4kW model, with each of the four rings having 2300W but being capable of delivering a 3200W power mode. The power mode takes almost 4 minutes to boil 500ml of water.

However, I also own a cheap portable 2000w single induction hob and different magnetic based saucepan for use in the workshop. Both pans (new and old) heat up 500ml of water on the cheap 2000w hob in around 2 minutes. Equally, both pans take near 4 minutes on the new 7.4 kW hob. As the saucepans perform similarly, this would seem to isolate the hob as the cause.

We had the hob professionally fitted and a new circuit was supposedly added to cope with the power requirements. I’m left slightly bewildered that a 2000w ring is boiling the same amount of water as a 3200w ring in half the time.

Any ideas what could be the cause? Or perhaps I’m overlooking other variables.

 

[Distinterior]

What make is the new Hob..?
A lot of the Bosch, Neff and Siemens models come with a free set of pans that are Induction compatible.

BUT, be aware a lot of aftermarket pans that you can buy may well be advertised as Induction compatible, but don't actually work as expected when placed on the Hob.....!!!
Check your pans that you are using on your new Hob with a magnet. The stronger the magnet sticks to the pan, the better it will work on the Induction Hob. For example, a Le Creuset cast iron pan is a safe bet coz it has a lot of iron in it. The lower the iron content, the poorer its performance.

 

[--Tom--]

If same pan with same amount of water is boiling slower the only variable is the hob and the amount of energy it is receiving.

 

[J_Ashley]

The hob is AEG and the pans are Circulon , so decent/middle of the road stuff. I've tested the new pans with a magnet, and the attraction seems decent enough. The old pan I compared out of the workshop is generic/unbranded, and seems to perform the same as the newer ones.

 

[CHJ]

Does your small shop hob have thinner ceramic surface, so that the pans are closer to the induction coil?
Might it be that the larger cooker has a much thicker ceramic because of the strength needed to carry the weight and span a bigger area.

 

[sunnybob]

Theres some interesting stuff here.
https://www.electriciansforums.co.uk/th ... ize.68239/

According to this you should have a seperate mcb of 32 amps.

 

[Phil Pascoe]

BUT, be aware a lot of aftermarket pans that you can buy may well be advertised as Induction compatible, but don't actually work as expected when placed on the Hob.....!!!

He has tried both pans on both hobs and got the same result.

 

[Phil Pascoe]

I've just boiled exactly 500ml on my Zanussi hob in a Le Creuset pan - one and a half minutes.

 

[Fitzroy]

If you have a smart meter you can watch how much power the stove is drawing. 500ml heated by 80degC over 4mins would require heat input of 787watts, all ideal of course.

F.

 

[Rorschach]

You got a faulty hob. It clearly isn't putting out it's full kW rating.

 

[Distinterior]

I can tell you from experience that not all pans work the same on all Induction Hobs..... Just because it works on the single Hob, doesn't mean it will necessarily work the same on another Hob. I have fitted dozens of Induction Hobs over the years and have had quite a few phone calls to say " the new Hob is not working".......I've gone round, tried one of the pans that was supplied free with the Hob and bingo!....The Hob works!

There is one other possibility that springs to mind. Often, these type of hobs are delivered with the option to be wired to 230v single phase supply or 415v 3 phase. There are sometimes copper links supplied loose that are used to common together terminals in the connection box. It may be worth checking in your installation instructions and taking a look at the terminals to ensure that all the links are there and in the correct place.

 

[Deejay]

Morning all

+1 for Disinterior's link suggestion.

Have you asked AEG?

Try ...

https://www.aeg.co.uk/support-hub/

for a start.

Cheers

Dave

 

[Lons]

I know nothing about them however we have an AEG slot in cooker with induction hob ( model 49176IW=MN ) bought a few years ago and use a set of Circulon pans without any issues whatsoever.
I haven't timed how long it takes to boil but it's pretty quick.

 

[J_Ashley]

I've just boiled exactly 500ml on my Zanussi hob in a Le Creuset pan - one and a half minutes.

They're the kind of figures I was expecting, and hence the assumption that something isn’t quite right.

According to this you should have a seperate mcb of 32 amps.

We had a 32a MCB installed to accommodate the hob, so, unless something hasn’t been done properly, there shouldn’t be an issue there.

Unfortunately the hob didn’t come with any free pans, so we don’t have any AEG approved pans to compare against. Obviously it’s not that practical to keep testing a multitude of different pan models to see if its the pan/hob interaction that's causing things to be a bit slow, but I’ll see what I can do. It makes me a bit suspicious that two different pans are performing almost identically, with both being lacklustre.

I guess the logical thing to do is contact AEG for their advice. I know the hob didn’t come pre-flexed in any way – not sure if that’s unusual/relevant or not. I’ll check out the paperwork to see if there is any 1 vs 3 phase references and subsequent wiring instructions.

 

[Distinterior]

What is the actual AEG model code of the Hob you have..? It should be on the label on the underside somewhere.

When Induction Hobs first became widely available in the domestic market, they used to be delivered with a pre wired flex.

More recently, they have been arriving without any cable but with the requirement to configure the connection terminals as I described in an earlier post.

 

[mbartlett99]

I very very nearly fitted my Bosch hob without looking at the connection box - it came with the links in the 415v position which surprised me as 3 phase is hardly super common in domestic buildings.

 

[Distinterior]

Bear in mind where the majority of these Hobs are made and who is their biggest market...? ........Europe!

The majority of European houses are equipped with 3 phase supply and as these Hobs are manufactured with this in mind, it makes perfect sense to have the facility built into them to be used in all scenarios.....I've never fitted one yet in all my years in the business that does not have this feature......

 

[Phil Pascoe]

Off tack, but don't get rid of pans that work but are slow- they're good for cooking things that burn and catch easily such as as scrambled egg and bechamel.

 

[J_Ashley]

What is the actual AEG model code of the Hob you have..? It should on the label on the underside somewhere.

The model is the AEG HK674400FB

 

[J_Ashley]

I’ve taken the hob off the surface to investigate further, and I’ve attached photos of the wiring diagram and the current wiring.

In case it’s of any use, the text on the cable appears to read (it’s hard to read, so some characters could be wrong):

(H058N4F) 3183TQ 302.5mm² 8S EN 50625 RF CE.