in-line heater test?

[Mike_Javelin]

I’ve a sick AEG Favorit 40850 dishwasher that does not seem to be heating the water anymore.

The heater is an inline type as in the photo,

A bigger version can be seen at http://gbr562.co.uk/d1.jpg

According to AEG it has a built in thermal cutout.
Two wires enter via the connector bock, top right and there is an earth connection at the bottom.

I took the connector block off and with power on I got 240v between one of the block terminals and the earth.
So I guess that its getting power ok but to double check have you got any ideas on how I can test the heater?

Cheers

Mike

[gegsy]

Re: in-line heater test?

I would imagine you have lost a neutral feed. Check heater terminals on block and should read between 25-30 ohms.

Greg

[Mike_Javelin]

Re: in-line heater test?

I tested between the two terminals and got 28.

So in short the problem is elsewhere?

probably on the neutral feed?

sorry on a steep learning curve 😮

[gegsy]

Re: in-line heater test?

Im not familiar with AEG but I would imagine they have a safety thermostat under base, possibly with a red button that you can press to reset :con:

Greg

[Mike_Javelin]

Re: in-line heater test?

no such luck.

The wires from the heater run to a plastic pressure sensitive relay

A small hose runs from the sump to the takeoff point shown.

It appears to trip given a very small bit of positive air pressure so I guess the water in the sump forces air down the tube to the relay.

Anyway checked it and it seems to opporate ok and the pipe seems clear.

The wiring starts to get a little more complicated now 😯

I gave AEG a ring and they said that there was no thermostat but there was a sensor but their diagram did not show where it was 😡

[Mike_Javelin]

Re: in-line heater test?

OK, a bit more in the saga,

two thickish wires run down from the main power switch on the fron panel to what I’ve incorrectly called a relay as its really just a pressure switch.

One of these power feeds is hard connected to a feed direct to the heater.
The other goes to one side of the pressure switch and when pressure is applied it trips over and this wire runs to the RELAY (hope I got it right this time 😳 ) shown below.

There are six wires into it (two of which are earths) but the terminals appear to be paired up.

How can I test this relay works?

[Mike_Javelin]

Re: in-line heater test?

😳 😳 😳

Just had a closer look at the wires running to the above relay.

Three double terminals,

One for earthing the whole machine,
One takes the main power live and the other the main power neutral.

So reversing my original hypothosis,

Power comes into the machine from the plug to the relay above.

The main neutral runs to the pressure switch but is hard wired to a thick blue wire that goes upto the main on/off switch.

The washing is mounting up so I really need to get to the bottom of this 😯

So in short,
I’ll dig a bit deeper.

😆

[gegsy]

Re: in-line heater test?

Really good stuff here guys, but what you are getting into now is more than really “basic” help for guiding a member of the public to repair their own appliance. We have to be very careful as not everyone has the same ability that you guys appear to have 😉
If you find the problem excellent and please share it with us all, but going into any more depth is not appropriate, sorry.

Greg

[Mike_Javelin]

Re: in-line heater test?

ok, just one more then, 😀

Just put it all back together just to check if I’d fixed it without knowing and guess what?

I haddn’t 😥

Ran the meter through the block connector to the heater again and got the following.

Terminal a to earth = 235 volts
Terminal b to earth = 35 volts
Terminal a to b = 60 volts

Not sure what this means but it doesn’t look right to me somehow.

Thanks for your patience

[Trilobite]

Re: in-line heater test?

Hi,

Are you sure it’s a relay? Looks to me like some sort of filter/capacitor… Could it be a different shape of suppressor?

[gegsy]

Re: in-line heater test?

Looks like supressor/ mains filter to me

Greg

[Penguin45]

Re: in-line heater test?

Mike,
You have an acceptable reading through the heater; your current investigations are now being conducted in the wrong place. There is no separate relay to switch the power to the heater, it is integral with the control board in the control panel. This is where you should look, especially for dry joints.

As no-one else has said it, power off, please.

UKW does not and will not condone or encourage “live testing” on any appliance – even as a professional there is rarely any actual need to perform it. It’s damn dangerous.

Regards,
Penguin45,
MODERATOR.

[gegsy]

Re: in-line heater test?

Bottom of my post

Greg

[Penguin45]

Re: in-line heater test?

Reinforcement……….

Or covering our collective backsides……

I’m quite sure that Mike is working his way through the problem in a logical and controlled manner – hopefully he’ll still be here in the morning to report his progress.

However, six months from now, who knows the abilities of the next seeker of knowledge…….. Will your signature still tell people to “Unplug before attempting any repair”?

Penguin45.

[gegsy]

Re: in-line heater test?

You right can never be too carefull guys :plug: always before attempting any repair.
I intend to keep my unplug sig but I know what u saying.

Greg

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