On Sunday, 5 February 2023 at 07:18:14 UTC, johnje...@gmail.com wrote:
> On Saturday, 4 February 2023 at 14:31:44 UTC, Tim+ wrote:
> > Our previously reliable electric kettle has taken to turning itself off a
> > few seconds after turning it on. If I hold the switch down it boils as
> > normal. It’s turning itself off long before and steam is generated so it
> > can’t be the normal cut-out that’s tripping and only if the kettle is
> > powered so it seems unlikely that it’s a simple mechanical fault.
> >
> > Anyone got any ideas as to what might be wrong? I’ve had a quick shufty
> > and there’s some surface corrosion on a spring disk that forms part of the
> > switch but not a lot. Can’t see how/why that would limit the switch to a
> > few seconds of functioning.
> >
> > Tim

> At current cost to replace with an El cheapo supermarket kettle I wouldn't waste more than five minutes of my time on it.

5 minutes for £20 = £240 an hour. I daresay most diyers don't make that much. The days of £3 kettles are over.

On Sunday, 5 February 2023 at 08:11:11 UTC, Paul wrote:
> On 2/4/2023 4:23 PM, Tim+ wrote:
> > Joe <j...@jretrading.com> wrote:
> >> On 4 Feb 2023 19:51:50 GMT
> >> Tim+ <tim.d...@gmail.com> wrote:
> >>
> >>> Nick Odell <nicko...@yahoo.ca> wrote:
> >>>> On 4 Feb 2023 14:31:39 GMT, Tim+ <tim.d...@gmail.com> wrote:
> >>>>
> >>>>>
> >>>>> Our previously reliable electric kettle has taken to turning
> >>>>> itself off a few seconds after turning it on. If I hold the
> >>>>> switch down it boils as normal. It’s turning itself off long
> >>>>> before and steam is generated so it can’t be the normal cut-out
> >>>>> that’s tripping and only if the kettle is powered so it seems
> >>>>> unlikely that it’s a simple mechanical fault.
> >>>>>
> >>>>> Anyone got any ideas as to what might be wrong? I’ve had a quick
> >>>>> shufty and there’s some surface corrosion on a spring disk that
> >>>>> forms part of the switch but not a lot. Can’t see how/why that
> >>>>> would limit the switch to a few seconds of functioning.
> >>>>>
> >>>> Just to add a couple of things to Bob Eager's post (which, by the
> >>>> way, is showing on Google Groups but doesn't seem to have arrived
> >>>> yet at ES)
> >>>>
> >>>> These kettles are designed to be removed from the base after the
> >>>> switch has clicked off. Consequently, cheaply made kettles (which
> >>>> may still be expensive to purchase) often have very robust plating
> >>>> on the switch contacts but rubbish plating on the base contacts.
> >>>> Lifting the kettle before it has been switched off often causes
> >>>> arcing which leaves those base contacts pitted and hard to keep
> >>>> bright.
> >>>
> >>> I’m not sure you’re right.
> >>>
> >>> My kettles have a central pin (non-current carrying) that passes
> >>> through into the base which switches the power off to the two annular
> >>> contacts before the kettle is clear of them when it’s lifted.
> >>>
> >>> Ours is a cheap Asda kettle which has kept us going for many year and
> >>> has often been lifted off the base before it’s switched itself off.
> >>> The contacts in the kettle base are in good condition.
> >>>
> >>>
> >>> A further clarification that may help with diagnosis though…
> >>>
> >>> When I turn my kettle on, the LEDs come on, indicating power to the
> >>> kettle. After several seconds a faint click comes from the bottom of
> >>> the kettle itself (not the lift off base) and the LEDs go out and the
> >>> kettle stops heating. The actual main switch that I depress to turn
> >>> the kettle on stays in the on position.
> >>>
> >>> It’s sounds like a stat or relay of some sort that is responding to
> >>> current flow but it’s not at all obvious where it is.
> >>>
> >>> I think I need to find a way of powering it up whilst I’ve got the
> >>> kettle partially dismembered. ;-)
> >>>
> >> Not being very helpful, but the switch mechanism has the extra
> >> complication of responding to the state of boiling, so the mechanical
> >> state keeping the switch on gets flipped off by a relatively small
> >> movement. You might be looking either for a fastening having loosened
> >> and made the mechanism 'hair trigger', or possibly that something has
> >> distorted with time and heat and now sits much closer to the 'turn it
> >> off' state.
> >>
> >> It may take only ten seconds for a turned-on kettle to start making
> >> noise, and I suspect that low-level vibration will occur before it
> >> actually becomes audible.
> >>
> >
> > Except, it’s not the main kettle switch that’s clicking off, it’s something
> > else in the base of the kettle that’s cutting the power.
> >
> > Tim
> >
> There's an example of a thermal cutoff in the bottom of this one.
>
> https://www.ifixit.com/Guide/Ovente+Electric+Kettle+KS88+Series+Disassembly/137016
>
> Not that seeing it open, is helping me.
>
> I presume a worn item with wear and tear on it,
> would give away its secret that way.
>
> It could be that the element has come loose of the base (corrosion),
> and the water is no longer sinking the heat.
>
> Paul

can't see the pics, but usually there's a bimetal switch plus a one shot overheat cutout. It can't be the latter misbehaving in this case, it can only really be the bimetal.

On 05/02/2023 18:54, Tim+ wrote:
> Max Demian <max_demian@bigfoot.com> wrote:
>> On 05/02/2023 12:00, Brian Gaff wrote:
>>
>>> I had this with a Murphy Richards one, and after a few squirts of wd 40, it
>>> worked. The normal kettle switch will not stay on if there is no power, so I
>>> can only assume that there is some way this is detected, and muck and
>>> limescale probably wedges this so it does not lock properly and hence it
>>> randomly falls out of lock.
>>
>> My £13 ASDA kettle doesn't flip the switch off if you turn off the
>> power; it comes back on when power is resumed. The main switch flips if
>> you raise it manually, remove the kettle from the stand, or when it
>> boils. There is also a lever in the circular contact thing on the base
>> that cuts the power to the contacts when raised. It is pressed down by
>> the neutral ring.
>>
>
> Ditto with mine. I can fill it and switch it on with no power and turn it
> on later with a Wi-Fi switch.
>
> Anyway, an update.
>
> I was able to loosen the kettle’s power receiving socket and on the
> underside there were two spring discs that seemed to be linked by push-rods
> to some inaccessible contacts. There was some dried up thermal paste
> around so I thought it couldn’t hurt to try replacing this. This had the
> opposite effect though. Kettle wouldn’t turn on at all! Just the briefest
> of flashes from the LEDs.
>
> So, then I tried removing all the paste but again this made no difference.
> I’m sure it should have some paste but clearly I’ve disturbed something
> during my repeated disassembly and assembly.
>
> I’ve given up. ;-)

Well new ones are cheap enough. ASDA still sell a similar one to mine:
https://direct.asda.com/george/home/kettles-toasters/black-kettle-17l/050462862,default,pd.html

(Previously I had a Wilko one but the stirrup that works the switch fell
off so I glued it back on with Araldite but now it only switches on from
completely cold, so I keep it as a spare.)

--
Max Demian

On 2/5/2023 1:54 PM, Tim+ wrote:
> Max Demian <max_demian@bigfoot.com> wrote:
>> On 05/02/2023 12:00, Brian Gaff wrote:
>>
>>> I had this with a Murphy Richards one, and after a few squirts of wd 40, it
>>> worked. The normal kettle switch will not stay on if there is no power, so I
>>> can only assume that there is some way this is detected, and muck and
>>> limescale probably wedges this so it does not lock properly and hence it
>>> randomly falls out of lock.
>>
>> My £13 ASDA kettle doesn't flip the switch off if you turn off the
>> power; it comes back on when power is resumed. The main switch flips if
>> you raise it manually, remove the kettle from the stand, or when it
>> boils. There is also a lever in the circular contact thing on the base
>> that cuts the power to the contacts when raised. It is pressed down by
>> the neutral ring.
>>
>
> Ditto with mine. I can fill it and switch it on with no power and turn it
> on later with a Wi-Fi switch.
>
> Anyway, an update.
>
> I was able to loosen the kettle’s power receiving socket and on the
> underside there were two spring discs that seemed to be linked by push-rods
> to some inaccessible contacts. There was some dried up thermal paste
> around so I thought it couldn’t hurt to try replacing this. This had the
> opposite effect though. Kettle wouldn’t turn on at all! Just the briefest
> of flashes from the LEDs.
>
> So, then I tried removing all the paste but again this made no difference.
> I’m sure it should have some paste but clearly I’ve disturbed something
> during my repeated disassembly and assembly.
>
> I’ve given up. ;-)
>
> Tim
>

That must be the "invisible tampering sensor" :-)

Paul

On 04/02/2023 14:31, Tim+ wrote:
>
> Our previously reliable electric kettle has taken to turning itself off a
> few seconds after turning it on. If I hold the switch down it boils as
> normal. It’s turning itself off long before and steam is generated so it
> can’t be the normal cut-out that’s tripping and only if the kettle is
> powered so it seems unlikely that it’s a simple mechanical fault.
>
> Anyone got any ideas as to what might be wrong? I’ve had a quick shufty
> and there’s some surface corrosion on a spring disk that forms part of the
> switch but not a lot. Can’t see how/why that would limit the switch to a
> few seconds of functioning.
>
> Tim
>
superglue the switch down