Smeg DF612SDX Dishwasher blows main fuse

[yardie]

Yes correct, be sure mains plug removed.
In 1st photo the heater is the silver metal cylinder to the right at the bottom.
Remove the 2 connectors and connect your meter with it set to lowest ohms settings.
Then connect meter on one heater connector ( either one) and the earth thats also on the heater with meter on highest ohms setting.
Record your results.

 

[CadwellParker]

Well I had my job cancelled this morning so was at a loose enough end I was able to see about testing the heater element. I didn't quite get that far though. As you can see from the photos, after disconnecting the black plug from the heater it appears to have been getting rather warm. Is this an obvious sign of the heater element being knackered? Do I need to test any further? Looks like the element has been pulling too much power through the plug...? Is there likely to be another cause of the melting plug?

Cheers

Untitled

• CadwellParker
• 26 Jan 2015
• 1

Melted plug close up

Untitled

• CadwellParker
• 26 Jan 2015
• 1

Melted plug

 

[yardie]

Go ahead and do the tests

 

[CadwellParker]

Ok, will do. Do I need to test on both the terminals in the melted plug as well as the earth? Do I connect both tester leads to both terminals in the melted plug at the same time and take that reading?

Feeling a bit confused here and hampered by a lack of basic electrical knowledge so if you could give a laymans guide to the steps involved here it'd be most helpful.

Many thanks so far for taking the time to help and advise.

 

[yardie]

Remove plug so NO mains power connected.

Check meter gets a reading by connecting your 2 meter probes together, what does the meter read? (On lowest ohms range)

Dmm on highest ohms range, connect each meter probe to each of the connectors inside the plug connector that was removed from the heater.
Record your findings.

Now connect the meter probes to the heater connections(lowest ohms range), are these connections burnt or corroded, need to be sure you are getting a good contact. Alternatively connect your probes to the long copper bars that are connected to the heater.
Record your findings.

 

[CadwellParker]

Are these connections burnt or corroded, need to be sure you are getting a good contact.

Record your findings.

Yes, there's little if any clean metal that I can see and the position of the terminals will make them hard to clean up. Will try the copper bars if needs be.

 

[yardie]

If the heater is ok it will be necessary to clean the contacts on the heater and the plug connector in order to continue using it.
Small flat bladed screwdriver to carefully scrape away corrosion./crud etc...

Read my previous post, edited with more detail. Note the ref's to meter settings.

 

[CadwellParker]

Remove plug so NO mains power connected.

Check meter gets a reading by connecting your 2 meter probes together, what does the meter read? (On lowest ohms range)

00.3

Dmm on highest ohms range, connect each meter probe to each of the connectors inside the plug connector that was removed from the heater.
Record your findings.

1.

This is the reading shown before connecting the meter. When connected to the connectors inside the black plug that was removed from the heater the reading on the meter doesn't change so I'm not sure whether I'm getting a proper reading here or not..

Now connect the meter probes to the heater connections(lowest ohms range)

30

Alternatively connect your probes to the long copper bars that are connected to the heater.
Record your findings.

I got the same reading from here as I did from the terminals on the heater.

30

What does this indicate?

 

[yardie]

These are basic tests but looks good so far.

Power off, unplugged.
Connect one meter probe to either heater connector (or copper bar) and the other probe to the earth on the heater or the chassis, meter on highest ohms range.
What reading do you get?

 

[CadwellParker]

These are basic tests but looks good so far.

Power off, unplugged.
Connect one meter probe to either heater connector (or copper bar) and the other probe to the earth on the heater or the chassis, meter on highest ohms range.
What reading do you get?

Same as when I connected to the connectors inside the black plug. THe reading remains at 1 and doesn't change.

 

[yardie]

Perhaps try running a wash programme (with heat) but with the heater connector left off.
It will take longer to run but will eliminate the heater if it does not blow the fuse.

The heater could be at fault whilst in use i.e as it heats up.

Whilst its running you could observe to see if any leaks and what the pump is doing. Bosch circulation pumps are exposed and easy to see, not sure about yours.

 

[CadwellParker]

The dishwasher runs for longer without the heater being connected, to the point where it realises the water's not being heated and switches itself into error mode. I cancelled that and started it running again and got the same result.

I can't see anything going on to indicate whether the pump's working properly or not but it sounds like everything's ok. There's definitely water flowing through the machine. I can see it passing through the plastic channel that runs up the side.

No sign of any water leaking anywhere.

 

[yardie]

Yes thought it might error but seems as though it is pointing towards the heater being faulty.
Ideally to properly test the heater you would need an insulation resistance tester like a megger but too costly just for one use.

Try and find a 2nd hand heater on the cheap and replace. They are around £20-25 but one ending on ebay in an hour if it will fit for £10 plus £3 post and has no bids.
These come in different bore sizes (the ends that connect to the rubber pipes) something like 28mm, 32mm, 40mm, measure yours to be sure which one. Get the wrong one and it won't fit onto the pipework.
It will have the wattage printed on the heater.
Not entirely sure if they come in different lengths? Worth checking that too.

You will also need to buy 2 new clips as the old ones cannot be re-used to secure the rubber pipes.

 

[CadwellParker]

Try and find a 2nd hand heater on the cheap and replace. They are around £20-25 but one ending on ebay in an hour if it will fit for £10 plus £3 post and has no bids.

Ok, that seems sensible. Thanks very much for all your help here. I had a look on Ebay but can't see anything ending this evening. I saw several of these...

http://www.ebay.co.uk/itm/Smeg-DW16...nces_Oven_Cooker_Hoods_ET&hash=item2ecf6ad543

The machine model number stated is different to ours but the part looks the same. I should probably replace the melted plug too. Where would I find one of those? Electrical factors?

 

[yardie]

Yes thats it but check wattage matches yours, bore ends and length.

Item numbers:

221666469669
171651423926

Probably easier to buy new female spade connectors with insulated covers.
Item number 370862665443

And dont forget jubilee hose clips/ steel band hose clips, re-useable ones
301117135404 but not for 40mm hoses.
Shop around for correct sizes to fit yours and better prices.