Zanussi Dryer Part Failure

[Ash]

Hi,

My washer dryer Zanussi (ZWT71201WA) recently stopped turning on. I read around and saw a post saying to try disconnecting the dryer element. Amazingly the machine now switches on and runs a wash normally! I need to fix the dryer part now though. I have bought a multi meter and tested the two obvious parts (the element and the thermostat). The readings have confused me though. The element seems to read 71 ohms which is a little more than most people’s advice suggests is normal? The thermostat reads 0 (which I believe means open circuit?). Can anyone advise how I can tell what parts need to be changed?

 

 Any advice would be really appreciated!
 

 

 

 

[Whitegoodshelp (Andy)]

Hello Ash. A heating element for the wash is normally roughly between 10 and 50 ohms. A heating element on the dryer section should be similar although it may be a smaller element. Can't give the exact readings but if faulty they normally go open circuit. The stat might be a thermistor full of heat sensitive crystals that change resistance according to temperature. Some can appear open circuit or only give a reading on certain setting ranges on the meter (How to test an NTC thermistor) but if it's actually a TOC then being open circuit indicates it's blown. If so you need to work out why as in most cases it's blown because the dryer section overheated.

[Ash]

Hi Andy,

Many thanks for your response, I appreciate it. I'm a little stumped then on this though, the part (and my scrawls) are visible in the photos below:

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Is there any way you could let me know what the part is from these photos?! I think it's this spare part: https://www.ransomspares.co.uk/parts/brands/zanussi/washing-machines/zwt71201wa (91460603800)/thermostat-temperature-regulator/77598.htm which is described as a 'THERMOSTAT TEMPERATURE REGULATOR' so I assumed a TOC?

Now you mention it, we have not looked at the filter on this machine (ever) assuming it has one. Sound like I should probably have a look to see if something is blocked! If not I must say I'm at a loss on what to do - clearly I wouldn't want to change the part and find out it is dangerous in some way...

Thanks again for your help with this.

 

Edited October 19, 2019 by Ash

[Whitegoodshelp (Andy)]

Hello Ash, the part in the photo shows a red manual reset button in the centre. If yours has one too it looks like it.

[Ash]

Hi Andy,

Yes the part does have the red thing sticking out between the terminals although whilst it looks like a button it doesn’t actually seem to want to be pushed in?! I’ve given it a good prod, but nothing moves or clicks. Is this something you’ve come across before?

I must say it left me confused. I could try again to see if it can be forced, but didn’t want to break anything further! I wasn’t sure whether the description as ‘thermostat temperature regulator’ mean it was a TOC or the thermistor you mentioned earlier.

As always, thanks for your response.

Ash

[Whitegoodshelp (Andy)]

If it has a reset button and it can’t be pressed in that suggests it hasn’t tripped. 

[Ash]

Hi Andy, 

Ok, so if it hasn’t tripped and is still showing open circuit does that just mean it’s faulty?! Or is it supposed to be open circuit?

I’m happy to replace it, but just don’t want to do it if not necessary - and then find out the element has a problem!

Thanks,

 

Ash

[Whitegoodshelp (Andy)]

Hello Ash. If it has a reset button in the middle then it must be a TOC (thermal overload cutout). Although it's theoretically possible for such a device to be open circuit and then close the circuit when activated I have never seen such a device. All TOC's I have ever come across  pass the power by default and when activated or blown they become open circuit. However, looking back at your original post I have never known a blown TOC to cause any other symptoms than for the heating element that it protects to stop working. 

[Ash]

Hi Andy,

Thanks for the advice - if you’ve never seen it before then I’m not really sure what to do!

i suppose I might just guess that it’s the TOC given that it’s OC but the reading for the element seems so high it also might have a fault that tripped the TOC. Not sure if I’m better off the changing both at the same time?

thanks again,

[Whitegoodshelp (Andy)]

You should look at the element to make sure it doesn’t have any obvious signs it’s knackered. A heating element is normally either open circuit or has a reading.