Washing Machine - now no heat

[rtcosic]

Previous help here

So now it works through its cycle but didn't stop washing.

Mr Google and Youtube told me that's a symptom of failed immersion heater - true enough it didn't get hot either.

Easy thinks I. Get it out of its hutch yet again, strip off the front, remove heater and thermistor(?) and prod at them with the multimeter.

Hmm. Heater shows c. 26Ω and properly open circuit to earth, so no obvious problem there.
Themistor show c. 64kΩ at ambient failing to c. 100Ω in very hot water and returning to 64 kΩ as it cools, so no obvious problem there either.

Looked for a temperature cutout or some such, but couldn't see anything obvious.

Buttoned it back up and find it does now complete the cycle - eventually - but doesn't heat up.

Take the heater out again and - carefully - rig up a temporary power supply to check it actually heats water? Can one fail but be neither open curcuit or dead short?
Can the thermistor fail by reducing resistance too quickly and give a false high reading?

Unless there is a well hidden temperature cutout that's failed that sounds like some issue with the power swtiching on the control board.

Any suggestions what to look for? Anything I can usefully prod with my multi-meter?

 

[Seadog]

Any suggestions what to look for? Anything I can usefully prod with my multi-meter?

Check to whether or not you have 240v on the immersion when the wash cycle starts.

 

[rtcosic]

Check to whether or not you have 240v on the immersion when the wash cycle starts.

Doh!

Of course.

It will be tricky to gain access to the relevant wires once it's all assembled, but I'll give it a go.

If you hear a dull thud and see a blue flash, it went wrong.

 

[Seadog]

Connect a couple of wires and lead them outside the cabinet. Make sure they're not shorting then fire it up.

 

[angellonewolf]

the element might look fine but as heats up can then go open curcuit as the element expands

 

[RonA]

Why not take the heater out & rig up some temporary 240v leads to check it’s warming up?
RonA

 

[rtcosic]

Connect a couple of wires and lead them outside the cabinet. Make sure they're not shorting then fire it up.

That was the way my mind was working too. Plan A

Why not take the heater out & rig up some temporary 240v leads to check it’s warming up?
RonA

Plan B

the element might look fine but as heats up can then go open curcuit as the element expands

That's what I was wondering too. Either Plan A or B should clarify that.

Will have to wait now. SWMBO has decided that a cold wash is fine for whatever she has put in it when I wasn't looking.

 

[snoozer]

she has put in it when I wasn't looking.

How does that work exactly ?

 

[normspanners]

element could have built in thermo switch coz that is where it needs to be ? just take it out connect 230 across it for a second or two and see if it gets warm.

 

[normspanners]

A short term fix is to pour your own hot water in whilst it is filling I made 9KG hover, hot fill but IMO it still doesnt fill enough even though I have adjusted its pressure switch, so if filling to max weight I also put a watering can in of hot water as well as the hot fill because it tops up with cold as the clothes soak up the water and now it washes excellent! you can hear it washing as the water sloshes through the clothes and now is about one hour quicker on a full 9 kg sometimes 10.5 kg ! wash cycle ! we now have no issues with skin reactions as we did have and use cheapest powder the rinse now fills half way up the glass ! it is ridicules all this about using min water you couldnt see any water circulating in the drum!, they expect people to not have dirty clothes nowadays I think, but my dirty oily clothes come out spotless. we used to have shrinkage and skin reactions some of that I think was the softener as well as powder but now nothing... MUCH better all round.
I modded the tumbler also putting a seperate heat control in and run it on half heat for twice as long, clothes dont need ironing at all and if they come out of the cuboards creased they get a spray of very diluted fabric condition and in the tumbler for 15 20 mins whilst showering and that knocks the creases out, obviously not your dress white shirts but jeans tees and sweatshirts all are good enough IMO . but even dress shirts take half the time to iron now. Stuff used to come out like it was tied in a knot !

 

[rtcosic]

I rigged up 'flying leads' to the element so I could safely check what was happening with the machine running:

1. c. 26Ω as before, so the flying leads are connected.
2. No volts at any point of any of the wash cycles.

Given the thermistor has high resistance cold and low when hot I figured an open circuit/infinite resistance should trigger the heating circuit, so I disconnected the thermistor - no change.

Followed the leads from the element. One goes to the control board the other to the level sensor which in turn has 2 leads to the control board.
Disconnected the 2 leads to the element at the board and level switch and got the same c. 26Ω as before, so there is no break in the supply wires.

As a replacement level sensor was less than £10 delivered I bought one from eBay on the off chance it might be at fault* and have just fitted it - no change.

This suggests that the fault lies with the control board.

Have I missed anything in my fault finding to get to that conclusion?

If the board has gone I am lost. I can visually check for obviously damaged components but anything more is beyond my skill set. I'm not paying £130+ for a new board compared to a new machine with warranty


* I had blown down the tube to the drum to check it was clear and blown/sucked into the sensor - before reading NOT to do the latter!

I have been filling the machine from the hot tap using a watering can in the interim. If I buy a new machine the current one can go into the garage for washing overalls etc using the watering can technique. That will please SWMBO.

 

[Wany]

Check ebay as there are firms that do washing machine/dryer pcb fix services. I paid £35, it tested ok and they sent it back and refunded £28. Motor was goosed, £180, no thanks.

 

[rtcosic]

Check ebay as there are firms that do washing machine/dryer pcb fix services. I paid £35, it tested ok and they sent it back and refunded £28. Motor was goosed, £180, no thanks.

I've used one for the hob with some success so that's an option.

http://www.qer.biz/servReps.htm

I'm looking for a critique of my diagnosis.

 

[rtcosic]

I think the magic smoke escaped.....

View media item 10663

 

[angellonewolf]

tiz but a flesh wound

 

[WorkshopChris]

Bottom right-hand corner whats on the opposite side of the 2 pins that look like the solder has vaporised or is it an optical illusion?

 

[rtcosic]

Bottom right-hand corner whats on the opposite side of the 2 pins that look like the solder has vaporised or is it an optical illusion?

No illusion! That's why I cropped the photo where I did. The 2 damaged/overheated connections are one of the power connections on the other side.

The other side of the board doesn't look at all healthy either. Lots of magic smoke made its escape.

I'm checking board repairers now.

It may just be resting.

 

[Seadog]

Two very dry joints. What's on the other side that's not well?

 

[rtcosic]

I've brushed off the carbon dust from the old brushes and cleaned with IPA.
Resoldered the dry joints, reassembled and now on test. Looking at the 'smart meter' to see if the heating element kicks in - easier than prodding with the multi-meter.

It may have just been resting after all - these Norwegian Blues are sneaky beasties.

 

[rtcosic]

Well, who is a clever boy then.

Watched the 'smart' meter jump by 2 kW. It got hot.

Got a proper wash on the go as we speak.

I may just possibly be in Brownie Point Central with SWMBO.

Told you those Norwegian Blues can't be trusted.