Cooker Hood & Hob Repair Guides
Cooker And Hob Hotplate Types
- Created: Tuesday, 10 October 2006 21:59
- Last Updated: Monday, 16 May 2016 16:31
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Hotplates, ringplates, ceramic plates, halogen plates, induction hobs; confused?
There are several options when it comes to cooking on a hobtop, whether that hob is attached to a cooker or a built-in hob and, when it is electric and not gas, it gets very confusing indeed with the options available. It's also really confusing as to what is or is not a DIY repair.
First things first, if you are going to attempt any cooker repairs yourself then get the power off it first so you don't get an electric shock. Always, always, always check that the power is totally off before working on one and DO NOT simply trust the cooker switch on the wall.
Radiant Ring Cookers
This is probably the oldest method for an electric cooker. To my knowledge this has been around since at least the 1950's and has remained popular until now as there are still a fair few cookers made using this type of heating plate.
Essentially it is a simple element in a flattened spiral configuration and comes in two sizes which are referred to by their respective standard sizes of 6 inches and 7 inches in diameter. Beyond that, with the 7 inch version there is a dual element one with two heating zones, what is sometimes referred to as the economy centre zone as well as the full zone.
The ring is supported by a tripod type support.
Usually, on most cookers that use these, the hob will simply lift up allowing access to change them or to clean under the actual cooking area.
These rings are pretty easy to change and are available from this section of our online shop
Solid Plate Hobs And Cookers
These are the ones with the black sealed plates.
Some people love them as they heat and cool slowly although the "rapid" plates, the ones with the red spot in the centre are certainly faster, personally I'm not a fan of them but they are a very good option (if not the only one) for people on a budget that cannot have a gas hob or gas topped cooker.
In essence they are a radiant ring encased in a light alloy casing, the heat is transferred through the metal to the pan to cook.
There are also the uot;simmer stat" type of plate, essentially the same but with a hole in the centre into which a thermostat fits that regulate the temperature far better. Do be careful with these in use though as, if the pan boils over and moisture gets in there it can blow the thermostat as well as risking damage to the heating element.
One of the problems with these types of plates is that, after a while they start to look a little tired as the chrome surround always discolours after use, you will almost always see that kind of "rainbow" effect on the chrome as if there was oil spilled on water. You can do nothing about this, it's just the way that the metal goes when heat is applied.
The other thing is that they tend to pit with little rust spots on the cooking surface. We get this as a customer complaint but it's really partially customer misuse. I say that because most manufacturers do advice that the plates should be wiped with oil on occasion, this is to stop the ingress of moisture which of course damages the surface of the cooking plate. The lesson there is that prevention is better than the cure, which can be replacement elements.
There is also the Collo hob restorer that we sell, it's actually well worth using as a prevention as well as a cure as it seals the element's cooking surface as well as keeping it nice an black looking. You can get this in online shop from this link and it's not expensive.
To get into replace these elements can be a bit of a chore, much like ceramic hobs, see below but they are pretty easy to replace and are available in this section of the shop
Ceramic Hobs And Cookers
Since I'm a relative newcomer to this industry, I've only been at it twenty odd years, I don't actually recall when ceramic hobs were introduced but I do know a fair bit about them as they have increased in popularity in the past fifteen years or so as the prices have dropped.
Most ceramic hobs and cookers are a bit of a nightmare to get into, the flush, easy to clean surface comes with that as a price when it comes to serviceability.
On most hobs you will find that it has to come out, so if the oven is underneath it that has to come out in order to release the clamps which hold the hob to the worktop. Once out there's usually what seems like a hundred screws to loosen off just to get the base off the thing, that's pretty normal. But you have to be careful here as some of the screws will almost inevitably also hold the actual heating elements in place and if you loosen off the wrong ones the elements will just flap about, which isn't good as I will explain in a bit.
On freestanding cookers, I used to curse the Belling ones, the side panels often have to come off, loads of screws, then the top has to be loosened off, loads of screws and then you can actually get to the elements themselves.
In short, to get into any of these you are facing slacking off a lot of screws and, if you don't know what you're doing it can take an age to work it out, the bigger problem though is the potential for damage.
Ceramic elements are, quite simply, pretty fragile things. In most you can see the actual element which sits in a heatproof dish made of some material which is normally beige in colour, I'm a bit vague here as I have just realised that I have never bothered to find out what it is. Never mind. The actual wire of the element isn't the problem really though, the temperature limiter is.
On all the ceramic elements that I've ever come across there is what appears to be a glass rod with electrical connections. This is the temperature limiter, a kind of safety device that cuts the plate in and out and these are very fragile and very prone to damage, hence there's not many engineers that have these plates rattling about in the back of the van.
So when you take apart the hob or cooker you have to be careful not to whack one of these as many manufacturers do not supply them as a spare part, they force you to buy a full new plate, usually at some ridiculous price. Which leads me nicely onto the fact that these things can be stupidly expensive, especially ones supplied from the manufacturer. Of course we source a bit smarter and can save considerable amounts on many brands where an alternative part can be used.
Some alternative parts are of course plain rubbish, we tend to favour the ones that come out the same factory as the original wherever we can. Same part, different part number and, on these heating elements you can save way over £50 just by shopping about on some.
A top tip for ceramic cookers and hobs fro cleaning is to use a good quality microfibre cloth like the one in our shop, which you can find from this link as that keeps the surface really nice. There are differences in the quality of these cloths as I have discovered and it's the old story, you get what you pay for to an extent. On test I found the cheap ones way inferior to the e-Cloth and the Electrolux one that we use
Halogen Hob Cookers
I recall when the Tricity Sovereign freestanding cooker was introduced, in its time it was pretty much a technical tour de force and top of the list was the fact that it had this new fangled halogen cooking zone, on later ones as I recall it became two halogen zones.
I have used halogen and I have to say I was left a little underwhelmed by the whole affair, it does look good though and the name sounds great, or at least it did in 1990.
As the name implies the principle is that the light, or heat generated from the halogen bulbs would heat up very rapidly and speed up cooking and therein lies the rub. They're bulbs and bulbs do fail. To get into most cookers with halogen heating zones is pretty much the same as getting into a ceramic hob as, really it's only an extension of that technology and the rules of dismantling are just the same. I think there were one or two halogen hobs but I've never seen one.
In general you can buy the plates complete for these types of cooker, but quite often you cannot buy just the bulbs which is a shame as that would be far cheaper than having to shell out about £100 on a plate. Of course if we can source bulbs we just replace them rather then the full plate.
Induction Cooking The New Way
Like most things technology moves on and, in the case of hobtop cooking, there are no exceptions. The current darling of the industry is the induction hob. Whilst I have never actually used one and nobody has yet offered one for test, the promises seem fantastic. Too fantastic? Not according to the manufacturers and the PR machines that they employ.
Of course the hype isn't without some justification.
One of the big benefits of induction cooking is that it's clean, or as clean as it can be. It's certainly easier, just as with ceramic hobs to clean a hunk of what is effectively glass, as opposed to a complex gas hob which has pan stands, burner caps and the burners themselves to clean.
Induction is currently most definitely NOT a DIY job.
Seriously, don't touch it. Even we struggle with them and they are not for the faint of heart. Often these hobs, like many of the new high-tech touch control ceramic hobs from the likes of Smeg are not for the DIY'er at all. They have fault codes and a bucketload of electronic trickery in them.
I know they look nice, I know that they're cool looking and nice things to own and operate, but they are technically advanced devices that use 240 Volts AC, you don't want to be messing with them if you don't have to.
Asides from which the parts are not cheap for this new breed of hobs and cookers, not in the slightest.
Once of the things we're always campaigning for in the industry is lower spares pricing and induction is one area where the prices aren't just ludicrous, they border on being illegal. For example, we found one electronic control board for a Whirlpool induction hob that costs more than a whole new hob, the exact same model it fitted!
These hobs are being heavily pushed in the trade press so far this year (2006) as being the next big thing, well it's also the next big bill to fix it when it eventually breaks.
CERAMIC HOB ELEMENT FAILUREI EMAILED YOURSELVES YESTERDAY AND GOT A SWIFT REPLY FROM DAVE CONWAY-THANKS. I HAVE RETESTED THE ELEMENT, TEMPERATURE SENSOR AND SWITCH ALL FOR CONTINUITY AND CAN FIND NO PROBLEM ALL APPEARS GOOD. HOWEVER WHAT I DID FIND WAS THAT THE SWITCH CONTROL CLICKED AFTER A FEW SECONDS AND THE VOLTAGE DROPPED TO ZERO. A FEW MOMENTS LATER IT CLICKED AGAIN AND THE VOLTAGE WAS RESTORED. IT CLICKED OUT AGAIN AND THE PATTERN OF EVENTS REPEATED.AT NO TIME WAS THERE ANY HEAT FROM THE ELEMENT. IN THE ABSENCE OF A PROPER DIAGNOSIS I THOUGHT THAT YOUR 1800WATT X 200MM \'UNIVERSAL\' UNIT MIGHT BE A RELATIVELY INEXPENSIVE WAY TO CONFIRM THAT THE ELEMENT WAS OR WAS NOT FAULTY. ANY IDEAS ABOUT THE PROBLEM BECAUSE I MAY STILL BE LEFT NOT KNOWING WHERE THE FAULT LIES.
ROGER CROUCH TEL 01273 881267