Re: Whirlpool dryer heater failure

"Only Just" <ifixit2@hotmail(dot)com> writes:

"Seán O'Leathlóbhair" <jwlawler@xxxxxxxxx> wrote in message
news:a9e49673-7736-400a-9272-5ab40cbb207e@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Feb 5, 11:27 am, jwlaw...@xxxxxxxxx wrote:
On Feb 4, 6:12 pm, jakdedert <jakded...@xxxxxxxxxxxxx> wrote:



jwlaw...@xxxxxxxxx wrote:
On Feb 4, 1:09 pm, Sam Goldwasser <s...@xxxxxxxxxxxxxxxxxxxx> wrote:
jwlaw...@xxxxxxxxx writes:
On Feb 4, 10:42 am, jwlaw...@xxxxxxxxx wrote:
My Whirlpool electric tumble dryer AWZ241 has failed. Last Friday,
the
house's circuit breaker tripped when it was turned on. After
resetting the circuit breaker and trying the dryer, it did not trip
again. The dyer runs but does not get hot. I guess that the
heater
and / or an internal fuse has blown.
Any other guesses of possible explanations?
Anyone know how easy this will be to fix?
I am not quite sure how old the dryer is. At least 5 years. It
came
with an offer of an extended 8 year guarantee but we did not take
it.
Anyway, it might be as much as 8 years old.
I have a good collection of tools (including a multimeter), access
to
a reasonably good spare parts shop, good understanding of
electricity,
and some experience of working of these devices. For example, I
have
successfully changed the drive belt of dryers and repaired the door
switches. I have not yet had any cause to open up this one.
I just checked the local spares shop. They could get me a new
element
in a day and it would cost £35. So, provided that is the fault and
it
is not too hard to change, it seems worth doing. Now, I need to
work
up the energy to take the thing apart.
It's very likely the heating element is the problem especially if the
dryer operated normally the laser time it was used. Replacement
should be straightforward. However, it's worth checking the
thermostatsm
and of course for lint buildup which can lead to overheating.

Thanks. Yes, the dryer was working apparently fine last Thursday. I
will check the thermostat as well when I have opened it up. Where
might lint build up except for the filter just inside the door? I
have already checked and cleaned this. There was little on it at the
time of failure, we clean it regularly.

Lint can build up anywhere in the airflow path...significant cause of
accidental fires. Check the entire exhaust path, both inside and
external to the dryer.

jak

Thanks again.

I was busy last night and will be busy again tonight but I should be
able to take it apart Wednesday. With some luck, I will have it
working by the weekend.

Took it apart tonight. It was easier than I expected. Unfortunately,
the next step, the diagnosis, was harder than I expected. So, a bit
of humble pie; I though that understanding the electrics would be the
easy bit.

Three wires: black, red, and brown come from the controller to the
element. The red and black go to little devices which might be
thermal cut-outs mounted on the side of the element. If they are cut-
outs then it is a puzzle that they are in both lines. The outputs
from these devices go the element itself. The brown goes directly to
the same element terminal as the red indirectly goes. What's going
here, is the brown a feedback to the controller so that it knows
whether the cut-out is passing current? But, if the other one failed
it wouldn't know.

Now the real puzzle. I don't know the power of the element but I
would guess at least 1kW and at most 3kW. So (at 240V), the
resistance should be a dozen or so ohms. However my meter thinks the
resistance is infinite even on the 20MOhm setting. So, this would
suggest the element is dead. However, the meter cannot detect any
voltage between any pair of the red, black, and brown wires. Surely
there are not two simultaneous faults: the element dying and something
wrong in the controller? A final explanation is that the controller
runs the motor for some time before sending power to the element. Is
this likely? I ran the dyer for about a minute with the meter
connected to the red and black wires.

--
Sean Ó Leathlobhair

The (little devices) are thermal cutouts, they are usually for different
temps being for low and high and have different temp ratings printed on
them, if you only have 1 drying temp 1 could be a safety cutout, if you have
the 2 temp there is a safety thermo somewhere else in the circuit. also
quite often there is a switch in the motor that controls the power to the
heater element which may fail at times, they are used so that the heater
won't operate if the motor/fan isn't working ( another safety feature). Also
when you tested for power at the element was the timer set at the "Cool
down" position where the motor/fan will operate without the heater to allow
the clothes to cool down to avoid wrinkling. Having such a high resistance
in the element indicates the element is faulty tho.
Good luck and leave a message if you still have problems.
(semi retired appliance tech)

What's the element look like? A long coiled wire or is it sealed?
If it's just a coil, the failure should be obvious.

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