Samsung ecobubble keeps blowing the heating element.

[zYx]

We have a model: WW90K5413UX - 5 years old. 4 months ago the heater stopped working so I replaced it. It stopped working again recently. Replaced it again today. 5 minutes later it's blown again.

The heater wasn't officially for this model but it's 230V and 2000W. Are there any other differences in those elements? What else could be causing the heater element to be fried within 5 minutes?

[Whitegoodshelp (Andy)]

Hi. If the new heater was 2000W and the old one was say 1500W it could be blowing the fuse because of too much current? Aso, how sure are you that it is the heaters blowing the fuses? You need an insulation test meter to locate the cause normally.

[andyr12345]

hello @zYx  - I am presuming you mean the element has 'blown' and not just the fuse in the plug - if it did blow was there a very big 'BANG' from the element because  this is the way they can normally go rather than fizzle out - especially if the heater element operated and was not fully immersed in water all over it (think about if you ran a kettle dry and thermal safety cutout did not work) 
but again on a washing machine that would have an NTC or thermal cut out before it got to that stage ... so that is a strange one. 

13a should i think theoretically take just over 3000w (and a fuse in the plug  blows much higher than that) - but if the element is supposed to be 1800w and you did replace it with 2000w and the element goes through some electronics on a main board that would not be good either and could burn out the electronic components with the extra wattage .. however if a 2kw one came out and you replaced it with an identical 2kw that should beOK , even if it was a element from a non-original manufacturers part. 

when you test the new  one with a continuity tester (with leads taken off the terminals) does it buzz (if your continuity meter has a buzzer in it) or have resistance - or does it show open circuit (just to make sure the element has gone open circuit) ?

[Whitegoodshelp (Andy)]

Hi Andy. They can literally “blow” but I was referring to them blowing the fuse due to a breakdown of the insulation inside. That is considerably more common, and you need an insulation test meter to detect it because there is no physical signs at all. 

[MelS]

I think washing machine elements usually have integrated thermal fuses at each end of the element, the one used in my Zanussi certainly does, so they'd go open circuit if the element overheats from being run when it wasn't underwater, unless the element shorts to earth via its metal jacket and blows the plug fuse first.

An element would typically be switched via a relay, and relay contacts can sometimes "weld"/stick  when they get old and damaged, however I'd expect the controller to check the heater relay contacts are open before locking the door, which powers up the circuit. 

Have you checked with a multimeter that the element has actually blown (either open circuit, or shorted to earth), you might get an error indicating the element if for example, the thermistor has failed. 

If you were testing the element using a heater test in diagnostic mode, it would probably skip pumping out, so would not be able to  check that the water level pressure sensor is working properly,  so you should run a valve test first to fill the machine with sufficient water first in case a blocked sensor is falsely showing the level is over the heater, which would have allowed the element to run dry.

Edited November 5 by MelS

[Whitegoodshelp (Andy)]

8 minutes ago, MelS said:

unless the element shorts to earth via its metal jacket and blows the plug fuse first

That’s what usually happens, and it causes main fuse to trip. The element is only stopped from touching the casing if the heater by powdered insulation which can break down. Also if the element t gets hit by something that can cause it. 

[zYx]

Hi guys,

Sorry about the late response. I was not notified about your replies.

What I meant was that the heating element kept failing, not fuse. The new heating element was showing approx. 26k ohm on my multimeter, and once "blown", the multimeter wasn't showing anything, as in, there was no contact between the two terminals. Bin.

I replaced a 2000W with 2000W.

So today, it turned out that the heating element was ON as soon as the washing machine was plugged into the mains.

I replaced it yet again today with a genuine but second-hand one, thinking the other ones were of poor quality. As soon as I switched the mains on. I immediately turned on the "baby wash" program, but I could also see and smell something burning. The washing machine started to fill with water, so I guess this saved the heater for the time being. The heating was working, so I turned the washing machine OFF by pressing the ON/OFF button on the washing machine with the water in the drum. The machine was still plugged into the mains. 

I could still hear the heater heating up the water, similar to the kettle noise. The noise stopped when I unplugged the machine from the power. I left it for a few minutes, plugged it back in, and I could still hear the heater again, so I unplugged it again and left it.

After a few minutes, I plugged it back in, and then the power went down, which is when the main fuse was tripped.

The heating element is installed properly, no shorted to anything. To me, it's the control unit or whatever is responsible for controlling how to turn the heating element on and off. Like this: https://www.ebay.co.uk/itm/185519823249

Hope this makes sense.

Any ideas? Is this repairable? 

@andyr12345, there is no noise. Only smell 😜 no error messages. The cycle completes like nothing happened. Well, not anymore as there's clearly a problem with it...

@MelS, we did run a diagnostic sequence on it, and all seemed to be working. When the heating element was on, it wasn't on for long enough to know if it was working or not. The temperature sensor seems to be ok, too - I tested it with my multimeter.

Edit:

I'm no pro in this area, but I can see that the black wire goes into the door lock, and the red wire goes to the terminal in the front PCB board. I found a wiring diagram that may or may not apply to my machine, but why is the black wire going to the door lock?

Later on, I plugged the washing machine back in, with the door open, water in, and the machine OFF. The machine started pumping the water out.

Would a faulty lock cause the heater to be constantly ON, or am I looking at a faulty PCB?

Edited November 8 by zYx
updates

[andyr12345]

hmmm ... not a relay welded on the main board . I should imagine when heat is called for from the element there is a low voltage/current sent from the mainboard to the heater relay which will have 240v (possibly 10amp) on one side of the relay to switch the heater element on and off - have you checked the relays inside the machine on the main board(s) and see if one is welded shut (in the always connected / always on position)?
 

[zYx]

57 minutes ago, andyr12345 said:

hmmm ... not a relay welded on the main board . I should imagine when heat is called for from the element there is a low voltage/current sent from the mainboard to the heater relay which will have 240v (possibly 10amp) on one side of the relay to switch the heater element on and off - have you checked the relays inside the machine on the main board(s) and see if one is welded shut (in the always connected / always on position)?
 

Not really sure what’s what here on this board. There are a couple of components that look like 2A and 3A relays and “bridge rectifier”. I took a few close up photos so hopefully the component numbers are visible  

Edited November 8 by zYx

[MelS]

The door lock has a switched output that provides one of the mains supply connections to some of the major components like the drum motor, valves and heating element so that they don't receive power when the door is not locked, as a safety feature. Both that and the relay for the element have to be on for the element to receive power.

It's possible that your machine doesn't check the heater relay is open before locking the door, If the machine refuses to run when the door is open, the lock must be ok.

It should be fairly easy to trace the circuit on the PCB from the element connector to find the element relay and you should be able to test if it is stuck on while the appliance is unplugged, by measuring resistance with your meter and check that the output from the door lock is disconnected when the door is unlocked, or open.

If it is a stuck relay, you may be able to confirm it by giving it a few gentle taps may jar the contacts free, but only temporarily, as the contacts will be knackered and they are likely to reweld very quickly when the heater is switched on. Replacing a relay is fairly straight forward, you should be able to find the same part, or else an equivalent relay with a matching footprint and coil rating and contact current rating from most electronic component suppliers. Avoid cheap Chinese relays if you can.

I believe samsung make life more difficult by smothering everything with conformal coating, a bit of googling should find a few recommendations for removing the stuff they use where you need to work on the PCB.

I've posted a circuit that's not from a samsung unfortunately, but which hopefully would be a fairly typical for a washing machine, as I thought it might be clearer how they are likely to be wired:

18 is the element with its integrated fuses, 17 is the door lock (its an instantaneous one hence the two door triacs instead of one) , J1-2 appears to be the output from the lock which powers up "line door" on the PCB on this machine which supplies live to the element and k1_wheat_RL is the element relay, which will be activated by the microprocessor as required connecting the element to neutral. The power is also isolated by the program selector on this machine.  (9,10,11 are the water valves)

 

Edited November 9 by MelS

[MelS]

Your last reply didn't show up in my browser when I posted my previous reply.

 

That large "Golden c1804-06b2", that I think you show one of the heater wire plugged on to, appears to be a high current relay with spade connector for the switched output. 

Test for a continuity between the two spade connectors on the top,  they should be normally open so open circuit when relay coil is not powered. 

If the relay contacts are open, there are two possibilities, either one of the components, probably a transistor on the PCB  that drives the relay coil has failed shorted on, or disturbing the board has caused the contacts to free. 

As it is rated at a beefy 25 amp, and the element is only around an 8 amp resistive load, I would think it would be less likely for the contacts to weld. 

 

 

 

Edited November 9 by MelS

[zYx]

38 minutes ago, MelS said:

Your last reply didn't show up in my browser when I posted my previous reply.

 

That large "Golden c1804-06b2", that I think you show one of the heater wire plugged on to, appears to be a high current relay with spade connector for the switched output. 

Test for a continuity between the two spade connectors on the top,  they should be normally open so open circuit when relay coil is not powered. 

If the relay contacts are open, there are two possibilities, either one of the components, probably a transistor on the PCB  that drives the relay coil has failed shorted on, or disturbing the board has caused the contacts to free. 

As it is rated at a beefy 25 amp, and the element is only around an 8 amp resistive load, I would think it would be less likely for the contacts to weld. 

 

 

 

I did test these two relays this morning, and there was continuity between the two terminals on both relays, which indicated that the relay was in a closed position. One relay was showing 0.0Ω, and the other one was something like 35MΩ...
I tapped it slightly a few times with my screwdriver, and there was no longer continuity between the two terminals.

The actual part number is GT-1A-12D. I just ordered a couple of new relays with the same spec and size, and I am hoping this will rectify my issue. I'll report back tomorrow.

[MelS]

 

There's a video here showing one method of tackling that wretched conformal coating:- 

youtu.be/FkTKILXjg3s

 

I seem to recall my brother bodging a hot knife blade attachment for an old soldering iron when he tackled a marine radio covered in the stuff many years ago, although I don't know if it worked well, or he used some other method to get it off. 

[zYx]

I replaced both relays. When pulling one out I managed to pull a small component that was stuck with the gel coating but I soldered it back on with small wires and then thread the wire through the hole to the other side of the PCB. Only because one of the PCB circuits was ripped with the gel breaking the connection to the other side..

I checked connections on both sides and all seems to be good. Installed the new relays back on and the washing machine seems to be working properly. 
 

I used my old solder to cut the holes at the back of the main PCB to gain access to the other side of both relays and then sealed it all with a car windscreen sealant 😜 

I took several pictures as I usually do. Maybe it'll help someone as I couldn't find anyone on the internet with the same problem 🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️ 

Hopefully, it'll last another 5 years at least. I've never repaired a washing machine so I shall add it to my resume 😎😛

Edit: the only weird thing I noticed is that the red key light is blinking after the cycle and even when the machine is off. Also, the last 1 minute of a cycle is stuck for 3 minutes whilst the red key light is flashing. During this time, I can open the door, and I don't think I should be able to.

There's a switch on the door, and I remember the machine was beeping when I opened/closed the door during a paused cycle, for example. There is no beep now, but I checked the switch, and there's nothing wrong with it. Other than that, the cycles we tried seem to go through OK-ish. The water gets warm when it should.

Could this indicate a faulty lock? Any other ideas? It doesn't seem faulty to me. The door is locked during a cycle when the red key light is solid on.

Edited November 10 by zYx

[Whitegoodshelp (Andy)]

19 hours ago, zYx said:

Could this indicate a faulty lock?

If the door locks and machine operates it sounds ok. If the door can be opened when the drum is revolving something is wrong. But if it only opens when it’s finished and only the pump is running it could be that the power to the door lock is being switched off at the end of the cycle but something is causing the pump to run on. 
 

Does it have a leak detection float switch in the base?

[andyr12345]

20 hours ago, zYx said:

I replaced both relays. When pulling one out I managed to pull a small component that was stuck with the gel coating but I soldered it back on with small wires and then thread the wire through the hole to the other side of the PCB. Only because one of the PCB circuits was ripped with the gel breaking the connection to the other side..

I checked connections on both sides and all seems to be good. Installed the new relays back on and the washing machine seems to be working properly. 
 

I used my old solder to cut the holes at the back of the main PCB to gain access to the other side of both relays and then sealed it all with a car windscreen sealant 😜 

I took several pictures as I usually do. Maybe it'll help someone as I couldn't find anyone on the internet with the same problem 🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️ 

Hopefully, it'll last another 5 years at least. I've never repaired a washing machine so I shall add it to my resume 😎😛

Edit: the only weird thing I noticed is that the red key light is blinking after the cycle and even when the machine is off. Also, the last 1 minute of a cycle is stuck for 3 minutes whilst the red key light is flashing. During this time, I can open the door, and I don't think I should be able to.

There's a switch on the door, and I remember the machine was beeping when I opened/closed the door during a paused cycle, for example. There is no beep now, but I checked the switch, and there's nothing wrong with it. Other than that, the cycles we tried seem to go through OK-ish. The water gets warm when it should.

Could this indicate a faulty lock? Any other ideas? It doesn't seem faulty to me. The door is locked during a cycle when the red key light is solid on.

 

very well done , it sounds like your hard work has paid off - a lot cheaper that buying a new washing machine for the price of a relay(s) and a bit of graft. 

There is reports on the samsung washer eu forums of a lot of Samsung Eco-bubble washing machines burning the live pins on the 13a 3 pin plugs in the UK after a certain amount of times - I wonder if there is any connection to these relays maybe not releasing and going to open circuit and getting stuck/welded on longer than there should be and drawing heavy current from the elements .... maybe there isnt I dont know ?

if you have the older samsung with the thermal lock that sometimes after a wash can flash the red door lock indicator on the panel up to a couple of minutes after the cycle , before it will let you open the wash door. the newer samsung's will let you open the door immediately after the wash cycle has finished but they have a different type of lock to the earlier washing machines 

[MelS]

Can you start a cycle with the door open? I suspect from your description that the mains output from the door lock is stuck on, so the CPU doesn't know that the door has unlocked at the end of the cycle and the element and valves would be able to power up while the door is unlocked if their relays stuck on.

If it is faulty, might be an idea to check if there have been any recalls on your machine for a faulty door catch, as you could get it fixed for free if it has.

I'm no expert, but that component that came off looks like it may be the diode connected across the relay coil, which blocks back EMF from the collapsing magnetic field when it is switched off, which would otherwise eventually fry the components that drive it.

I wouldn't have bothered sealing the board, other than possibly taping over, or sealing the hole cut in the plastic, neither my current zanussi, nor at least two previous hotpoints I've fixed used conformal coating.    

As the element has previously overheated, if you should have the back off again, and haven't already done so, I'd suggest checking the state of the insulation of the wire where they connect to the element to make sure its not melted through, and insulate if necessary.

I would wonder about the quality of those Golden relays Samsung used, I'd have expected a 25amp one to last longer than that, my own machine uses 10 amp miniature "sugar cube" relays. 

 

 

Edited November 11 by MelS

[zYx]

9 hours ago, Whitegoodshelp (Andy) said:

If the door locks and machine operates it sounds ok. If the door can be opened when the drum is revolving something is wrong. But if it only opens when it’s finished and only the pump is running it could be that the power to the door lock is being switched off at the end of the cycle but something is causing the pump to run on. 
 

Does it have a leak detection float switch in the base?

I can't open the door, no. When the cycle is finished, the red key icon changes from solid ON to flashing, but 1 minute is still displayed on the front panel. About a minute later, I can open the door. It takes about a further 2 minutes (with a blinking red key and 1 minute displayed) before the cycle-complete-tune is played. When I'm not in front of the machine, it doesn't really matter as long as the cycle is fully completed.

I'm not sure if it has a leak-detection switch. I didn't see one. Why?

8 hours ago, andyr12345 said:

very well done , it sounds like your hard work has paid off - a lot cheaper that buying a new washing machine for the price of a relay(s) and a bit of graft. 

There is reports on the samsung washer eu forums of a lot of Samsung Eco-bubble washing machines burning the live pins on the 13a 3 pin plugs in the UK after a certain amount of times - I wonder if there is any connection to these relays maybe not releasing and going to open circuit and getting stuck/welded on longer than there should be and drawing heavy current from the elements .... maybe there isnt I dont know ?

if you have the older samsung with the thermal lock that sometimes after a wash can flash the red door lock indicator on the panel up to a couple of minutes after the cycle , before it will let you open the wash door. the newer samsung's will let you open the door immediately after the wash cycle has finished but they have a different type of lock to the earlier washing machines 

The machine looks clean and dry, like new.

The failing relay/s now make sense when the heating element failed in June. A new one would work for a couple of months. Then I went on holiday, and when I came back, it was working again. Two months later, it was fried again.

Normally, I had to wait about 1-2 minutes after the cycle was complete to open the door.

51 minutes ago, MelS said:

Can you start a cycle with the door open? I suspect from your description that the mains output from the door lock is stuck on, so the CPU doesn't know that the door has unlocked at the end of the cycle and the element and valves would be able to power up while the door is unlocked if their relays stuck on.

If it is faulty, might be an idea to check if there have been any recalls on your machine for a faulty door catch, as you could get it fixed for free if it has.

I'm no expert, but that component that came off looks like it may be the diode connected across the relay coil, which blocks back EMF from the collapsing magnetic field when it is switched off, which would otherwise eventually fry the components that drive it.

I wouldn't have bothered sealing the board, other than possibly taping over, or sealing the hole cut in the plastic, neither my current zanussi, nor at least two previous hotpoints I've fixed used conformal coating.    

As the element has previously overheated, if you should have the back off again, and haven't already done so, I'd suggest checking the state of the insulation of the wire where they connect to the element to make sure its not melted through, and insulate if necessary.

I would wonder about the quality of those Golden relays Samsung used, I'd have expected a 25amp one to last longer than that, my own machine uses 10 amp miniature "sugar cube" relays. 

 

 

No, I can't start a cycle with the door open.

When I pause the cycle, I still have to wait a minute to open the door and if I try to resume the cycle with the door open, I get a "dC" error code. The cycle won't resume until I shut the door.

The machine behaves as expected throughout, apart from the last 1 minute and the endlessly blinking red key.

All wires look fine. None of that needed a repair in this area.

Regarding the relays, I couldn't find the same ones here in the UK. Mostly from China, but I found the same spec at RS Components. And yes, 25A is more than enough. Maybe something happened with the relay/s when the heating element went the first time in June.

I'll keep an eye on ebay, and if a cheap PCB pops up, I might get it as a backup.

[MelS]

8 hours ago, andyr12345 said:

very well done , it sounds like your hard work has paid off - a lot cheaper that buying a new washing machine for the price of a relay(s) and a bit of graft. 

There is reports on the samsung washer eu forums of a lot of Samsung Eco-bubble washing machines burning the live pins on the 13a 3 pin plugs in the UK after a certain amount of times - I wonder if there is any connection to these relays maybe not releasing and going to open circuit and getting stuck/welded on longer than there should be and drawing heavy current from the elements .... maybe there isnt I dont know ?

if you have the older samsung with the thermal lock that sometimes after a wash can flash the red door lock indicator on the panel up to a couple of minutes after the cycle , before it will let you open the wash door. the newer samsung's will let you open the door immediately after the wash cycle has finished but they have a different type of lock to the earlier washing machines 

Those capacitors for the inverter would (very briefly) cause a fair surge in current while charging up, shouldn't damage the plug though. The 25 amp relay close to the caps could be something to do with power to the inverter, I suppose, or powering down the machine when on standby, or maybe for the recirculation pump.

Quite a few smaller relays on that board too, I guess it is using relays for controlling low current components like the valves and the pumps, instead of surface mounted triacs like mine does. With all that conformal compound I guess smt triacs might get too hot.

[Whitegoodshelp (Andy)]

14 hours ago, zYx said:

I'm not sure if it has a leak-detection switch. I didn't see one. Why?

If the float switch gets stuck, or there is an actual leak activating it, then it can cause the pump to run on when the cycle has finished because it's trying to get rid of the water in the machine that is "leaking into the base" and activating it.

[andyr12345]

@zYx - I know this can sound absolutely crazy , but have you initiated a 'drum calibration' cycle with your Samsung after all the moving you have been doing with it and it might just reset things ... (possibly?) - it maybe will sort out the problem you have with the flashing red key at the end of the cycle and reset all the electronics.
Its all built in there into the machine (the calibration program) so it costs nothing to try. - Run it with nothing in the drum.

 

Edited November 12 by andyr12345

[MelS]

Beyond what's already been suggested, I guess a remote possibly is a slight earth leak (most likely the element) might cause an  unexpected voltage on one of the inputs monitored by the CPU (like door locked, relay contacts connected etc), since they require negligible current, causing unexpected behaviour.

Most likely would trip the RCD instead, assuming the ring main is on one.

 

Edited November 13 by MelS

[zYx]

12 hours ago, andyr12345 said:

@zYx - I know this can sound absolutely crazy , but have you initiated a 'drum calibration' cycle with your Samsung after all the moving you have been doing with it and it might just reset things ... (possibly?) - it maybe will sort out the problem you have with the flashing red key at the end of the cycle and reset all the electronics.
Its all built in there into the machine (the calibration program) so it costs nothing to try. - Run it with nothing in the drum.

 

I did that, and it didn't change anything

17 hours ago, Whitegoodshelp (Andy) said:

If the float switch gets stuck, or there is an actual leak activating it, then it can cause the pump to run on when the cycle has finished because it's trying to get rid of the water in the machine that is "leaking into the base" and activating it.

This has only happened once thus far...

8 hours ago, MelS said:

Beyond what's already been suggested, I guess a remote possibly is a slight earth leak (most likely the element) might cause an  unexpected voltage on one of the inputs monitored by the CPU (like door locked, relay contacts connected etc), since they require negligible current, causing unexpected behaviour.

Most likely would trip the RCD instead, assuming the ring main is on one.

 

When I googled it, there was only one person with this specific issue, and they claimed that, in their case, it was the heating element that needed a replacement. The red key stopped blinking.

https://eu.community.samsung.com/t5/home-appliances/blinking-red-key-on-samsung-wf906u4sawq/td-p/1093615#:~:text=If you see a key,machine has detected an error.

Edited November 13 by zYx

[MelS]

Chances are they didn't have a "modern" consumer unit with RCD protection, almost certainly an earth leak would trip the RCD when the machine was running, if the circuit is protected by one. 

If you don't have an RCD, could try putting your multimeter on its highest megaohm range and measuring between earth and the two power connections to the element (while unplugged from mains), would probably show a connection despite the very low test voltage.

Looking at the docs for my Zanussi, on some models the stray voltage from an element earth leak can trigger a pressure sensor error, drain fault, or heater relay fault. On mine it actually tests for an element earth leak and should throw a ground fault error. 

 

Edited November 13 by MelS

[andyr12345]

I used to work on a Electrical Trade Counter at a builders providers back in 1989 even back then the norm for consumer units were ELCB's (earth leakage breakers) so they have been around for years fitted to CU's .