Welcome to the community @susan.gondwanatextil
Your inquiry has been moved to an existing topic. A useful place for any feedback that will further understanding of how to use induction cooking.
@BrendanMays, perhaps one of the review team knows where to find an answer?
Hi Susan, thanks for your question. That is an interesting use case, I’m not sure we’ve come across it before!
Because of the size of the pot/water, I would think that you’d be looking for a bigger model for heating efficiency and durability. The largest we test is 90cm x 52cm, so if it’s urgent, you could check out these models and also send a question directly to the manufacturer. I’ll check in with our product testers and see what they think to see if we can help you out. Just bear with me, it may take a day or two to investigate and I’m aware we have a public holiday weekend. I’ll get back to you as soon as we can.
You could still use a portable induction hob, I’ve certainly loaded mine up to more than 10kg when doing large batches of fig or cherry jam in a 24cm pot- which itself weighs 3kg.
For a 20l pot I expect the base would hang over the sides, so just use a couple of pieces of wood cut to the same height as the portable hob, or something of the right thickness able to take the weight, to support some or all of the weight of the pot. The pot doesn’t have to be resting on the hob at all, it can be a millimetre or 2 above the hob and still function perfectly well.
Like this (all I could lay my hands on that was the right height):
That made the pan the thickness of a butter knife above the hob, and it worked normally.
I use a 90cm induction stove with a 3.5kw large burner for processing bottled fruit. My waterbath is about 34cm in diameter and 40cm high which is about 36l. It is never full to the brim but it does include glass jars. My guess is the all up weight is between 25 and 30 kg in operation. I haven’t broken it yet.
Perhaps you should ask the manufacturers of the models you are interested in what they will take.
Welcome to the community @susan.gondwanatextil.
Looking online the maximum pot (design) weight for induction cooktops is dependant on the glass thickness. The thinner the glass, the lower the maximum weight.
I expect that different manufacturers and product models will have different potential maximum weight ratings. Looking at a number of manuals and websites for various brands, this information isn’t indicated in specifications. It appears that maximum diameters are the only maximums outlined.
As 20L may be consider more than that which would be considered domestic use, it might involve looking at commercial (kitchen) type cooktops which will be designed for larger and heavier loads/pots.
The risk of buying a domestic cooker and then failing at some stage during its life, it may be considered ‘misuse’ and thus not covered by manufacturer’s warranty or the Australian Consumer Guarantee. This is why when you are looking at options, it will be very important to get written confirmation that the cooktop can handle the weights you plan to use.
thank you for such a thorough response phb, and also Gordon, Brendan and syncretic for your replies - it certainly throws a light on solutions and queries I have around this challenge. On a recent occasion, I was asked to do a workshop for 12 people in a regional gallery, but not to use gas. that’s when I bought 3 portable induction cookers. Can you imagine,12 people each creating small pieces to be dyed for 2 hrs in small pots of water (and eucalyptus leaves) that weighed no more than 7 KG total each, - we managed, and their experience was successful. Had I thought of the supports either side of the cook-top, to account for the overhang, and the excess weight, I would have been relieved of the challenge. I haven’t used the units since, thinking that the purchase was a folly, but I will now set up a dyeing station with timber supports (or little chinese bowls!) and see how they work. I look forward to hearing further to this problem.
There ought not to be any problem if you can get the base of the pot a millimetre or two from the stove top, much more and it will lose efficiency very quickly and possibly activate the stove’s “no pot” detection which will switch it off.
If getting a carpenter to make it (or DIY) make the frame a fraction too high and then plane it down until it is just the right height. Depending on the manufacturing tolerances of the stoves, wear on the feet, etc, you may have to make each frame to match its stove and not mix them up.
good thoughts - just altered my whole post flood, studio rebuild design. Instead of two induction portable units stuffed away into a cupboard, I’ll build in a dyeing station, with timber surrounds to support the weight, and put them both back to work. Making the support portable will also mean that I can take them to do workshops elsewhere, and forget about the gas setup and restrictions. That way I may not have to consider them within my kitchen scenario at all, which was the original reason for the investigation. Still would be handy to know the weight limitfor the built in cook-top.
Which brand and model number? Experience with different brands, customer support can vary. It’s always worth trying the phone contact, or email/social media contact details supplied with the product, or from their web page.
Without specific product details any answer is likely a guess. The typical recommendations for induction cookware include a smooth and flat base. @gordon solution solves the risk of any dishing or variation in the base of a larger pot loading up one point of a cooktop glass unevenly.
P.S.
I’ve found the packs of shims used in framing work (Mitre10, Bunnings etc) an easy way to make small adjustments (permanent or removable if something needs later adjustment). They can be readily cut into smaller sized pieces.
Hi Brendan any further thoughts on the weight bearing capacity of induction cookers. seems that glass thickness is a factor- how do you tell this? were you able to find any tests or evidence of weight limits?
While glass thickness might be a factor, on its own it is not going to provide a definitive answer. Ceramic glass varies in its properties and composition depending on the manufacturer and intended purpose.
Looking to your particular interest, the strength of the supporting frame may be a greater point of concern than the relative strength of the glass panel.
As previously suggested,
Background:
One well known manufacturer of cooktops etc says their products “are tested for a maximum weight limit of 50lbs”.
Manufacturers of cooktops can choose between glass suppliers, each of whom make claims their product is a better choice because ……
EG https://www.schott-ceran.com/en/benefits
The weight limit for a cooktop is about more than the glass panel used. The actual strength in an application is determined by the detailed product design. To consider are the relative strength of the frame, the unsupported span, deflection of the components under load and how the glass is anchored in the frame.
Since GE (USA) can answer the question asked of their products, it’s likely its competitors can also provide advice on the weight limit for each of their products. Relying on other than the product manufacturer’s advice on the weight limit could risk damaging the induction cooker with no recourse through warranty.
Hi Susan, sorry it took a little while for us to try to find a definitive answer for you. Here’s what our kitchen expert had to say:
All domestic portable induction cooktops have a very low weight limit - often under 10kg. Larger built- in units should be fine with 20kg, but I don’t think too much more than that.
There’s no reference to a weight limit for built-in ceramic hobs in the safety standard. But there is a drop test which equates to about 17N. But force limits are always lower than static weight…
So, they’ll need to look at built-in options, or perhaps a commercial portable induction (expensive) which may have higher weight limits. But they will need to match the base diameter of their pot with the element size - 20L pots to be effective would need a large base 30cm plus (often 36cm), which is not that common in an induction cooktop - definitely not in the domestic portable range we tested.
I hope that info along with the replies here have given you some help. We’d love to hear any updates as you go!
I have an ikea induction cooktop which has been great, however it appears to me that the element that I use the most does not perform as well as it used to. For example, I used to have it at 7 for boiling the water under a steamer full of vegetables but now I have to set it at 8. Is there some standard I could use to test how efficiently it reaches a certain temperature or something like that?
Power loss over time is a common occurrence with induction cooktops. It is highly likely your induction cooktop has suffered this fate and why you find you have to use higher settings to reach the same temperature or because cooking takes longer when usual.
Domestic induction cooktop ‘elements’ have a life of about 10,000 hours. Depending on its quality, it could have a life more or less than this. The life of an induction cooktop is based on when power output/heating ability or efficiency diminishes considerably.
Have you contacted IKEA customer support with your concern?
Is your product still able to perform despite the small change in the setting now needing 8 in place of 7? It’s possible there is no fault with the induction coil and power electronics. The reason for the change could be due to a control/sensor aging, or something different with your pot. EG dished base, delamination of an alloy composite pot insert, other.
Edit - the short answer is manufacturers appear to set their own standards for acceptable performance.
There are test methods and procedures. Note however every product is different. Performance is also dependent on variations between pots by size, materials and constructions. Without knowing the original detailed specification of the induction element, any test can only be subjective. IKEA’s design/supplier chain will be the ones who can advise on the original performance specification. Any testing would require this information to compare with your specific product. Additionally one would need to be capable of carrying out IKEA’s test procedures in the average home kitchen. This would require the exact same pot or test piece used used by IKEA’s tester or test agency, and high accuracy electrical test equipment.
P.S.
Wikipedia has a useful but technical article on induction cooktop element performance.
‘Induction cooking - Wikipedia
I haven’t noticed any power output deterioration in our 2 induction hobs, both of which are quite a few years old now, although the top has come loose on the oldest one, which must be about 10 years old, (I need to glue it back on!). Both will maintain a water boil on setting 3 for steaming vegetables.
If you want to make your own reference standard- use say 500ml of water a kettle or saucepan, and time how long it takes to come to the boil on say setting 3, 5 and 8, and record the times for future reference. Just use the same container and 500ml water each time you test.
Reading through the Flame Out, From Gas to Induction article I noticed under the subheading Installation (p32-33) that it says “You may also need to check if the power supplied to your home has adequate wattage to service the cook-top.” and later says “You may also need an extra circuit to accommodate the higher wattage…”
Should the term amperage be used instead of wattage? As the article does mention 10Amp, 20A, 32A and 42A connections.
The key thing is the power requirements. And that unit is Watts.
However, the supply voltage is constant, so more power requirement means more current flow, and that effects wiring needed.
Perhaps the article should have explained that typically electric devices with power requirements greater than around 2400 watts are put on higher amp wiring than the standard 10 amp loops used for lighting and power points.
Typically cooking elements are rated in watts. IE power out. The same applies for electric kettles, toasters, microwaves etc. It’s a simplified guide to the relative cooking power when comparing products. It’s also comparable when comparing different types of cooking devices including gas burners. The amperage of an electrical appliance measures the power input. The efficiency of different types of cooking element varies which makes amperage less reliable for comparisons.
However amperage is what your electrician relies on when installing an induction cooktop, oven etc. The electrician has a set of rules for sizing the cabling required based on the type of load and rated load current (per the manufacturers data sheet) for the product.
There are also rules for the electrician to determine the total load current (amps) from all the circuits connected in a property. It’s a pass or fail assessment, which will determine if the incoming supply and cabling to the property comply with the distributors requirements. There is an assessment for the average household that only some and not all electrical items will be in use at the same time.
Determining whether a property requires an upgrade to the connected power supply varies according to installed electrical circuits/appliances, property type, location, and distributor. The decisions made rely on reference to the applicable, codes, standards and distributors connection rules. Something best left to those with the knowledge and skills for advice.
