Washing machine intermittently trips RCD. Manufacturer declares machine fault-free and suggests faulty home electrics. What should I do?

[GreenGoblin]

Hi

I don’t know how resolve this so any helpful advice would be greatly appreciated. I have no electrical knowledge. I will try to be as clear and detailed as I can.

I’ve got a Bosch washing machine that’s two-and-a-half years old. Until early June, the machine has been flawless. But in June, my machine began intermittently tripping the electrics. At first it was one trip during the two hour cycle every couple of weeks, but this gradually grew to one trip almost every time I used it.

Naturally I presumed it was a fault with the machine because I don’t get any electrical trips when the machine is not in use. So I called Bosch and arranged an engineer visit. The engineer came and began by checking the mains power socket by plugging in a device with a bunch of LEDs on it. It didn’t show any faults. He then did some tests to rule out faults with the machine's major components (namely the motor and heating element).

He then unplugged the machine, pulled it out, took the back panel off and looked inside. After doing this, he said he couldn’t find any faults with the machine and suggested that the dedicated mains socket (for the machine) was faulty. Now this Bosch engineer had previously visited me two years ago when I had the same problem with my previous Bosch washer. Back then he also declared the machine fault free and said it was my mains socket at fault. He explained that the wires are likely worn out and this is causing the trip.

So I reminded him that he gave me the same excuse two years ago and asked him how my current washer was able to run for over two years without any problems. He said the wires inside the socket can get worn out, but sometimes it can keep working. I didn’t accept this explanation and asked him to remove the top panel of the machine to inspect the wires properly. He said he didn’t to do this and this started an argument. Anyway he ended up storming out.

I contacted Bosch and explained that I disagreed with the engineer’s conclusion and explained that I felt he didn’t inspect the machine properly. Bosch referred my case to their technical department and they came back and said that in their view the machine was inspected properly and is fault free. They said if the problem was with the machine the trips would be more frequent. Bosch said the likely cause of my problem is something called “nuisance tripping” as a result of earth leakage. They said I should contact an electrician and ensure that an RCD is fitted with a unit that has a symbol that I can best describe as two curly lines (my RCD doesn’t have this symbol).

Bosch told me I could get a second opinion from a second engineer, but that they stand by their technical department’s and the visiting engineer’s evaluation. I said I would be in touch when I had video evidence of the machine tripping.

From the day of the engineer’s visit (14 June), I filmed every last 30 minutes of the wash cycle as the tripping usually happens during this phase (where it goes through two rinse cycles, followed by a final spin) hoping to catch the fault on video and nothing happened. I filmed for two months and stopped a couple of weeks ago, having come to the conclusion that the fault had miraculously resolved itself.

Then today I run the machine and it trips the mains just as it was about start up its final spin. I reset the RCD and it completed the cycle from where it was interrupted. I just don’t know what to do now. I’m convinced the fault lies with the machine itself because my mains only trips when it is in operation. Nothing has changed in the last two months in terms of my electrical setup. A fault with the machine seems like the most obvious explanation. What I don’t get is why I had no problems since the engineer’s visit. If it really were the mains socket or my RCD, then how could I go 8 weeks using the machine without any trips?

I don’t know whether I should go back to Bosch or get an electrician to look at the RCD. Both will cost me (my machine is out of warranty). My questions are:

1. Where do you think the fault likely lies based on what I have described? Do you think it’s the machine or the RCD /electrics in my home?

2. Why do you think I have been able to get two months of fault free washing since the engineer’s visit? The engineer unplugged the machine during his visit. Could this have “disrupted” any earth leakage issues and given me some temporary relief from the intermittent tripping? (Usually the machine is permanently plugged into its dedicated mains socket.)

3. Do you think I should get in touch with an electrician or go back to Bosch and insist that there is a fault. I plan to start filming the machine again from tomorrow to get video evidence of it tripping during operation.


If you need any further information, feel free to ask.

I’d be grateful for any suggestions.

 

[radiohead]

You say in your post to get an electrician to do an IR test, but with an EICR the electrician should be doing a lot more tests, I was thinking along the line if the EICR turned out to be satisfactory, then that may go some way to proving, nay indicating that the fault may in some way lie with the WM ,I also feel that getting a Spark to do an IR test is not going the full distance, a satisfactory EICR should do that, a signed document if you like.

An EICR will (or should) cost the OP a couple of hundred quid and despite what you suggest cannot be guaranteed to identify all problems. I can see no reason to spend that for apparently a single issue. Investigate the known issue and if that investigation suggests an EICR is required then it can be recommended.

 

[Pete999]

An EICR will (or should) cost the OP a couple of hundred quid and despite what you suggest cannot be guaranteed to identify all problems. I can see no reason to spend that for apparently a single issue. Investigate the known issue and if that investigation suggests an EICR is required then it can be recommended.

Thought tha's what we are doing with a "known issue", checking to see if the installation is up to a satisfactory standard.

 

[multimick]

Also as an aside only the more expensive machines are made in Germany the cheaper ones are made in Turkey

 

[radiohead]

Thought tha's what we are doing with a "known issue", checking to see if the installation is up to a satisfactory standard.

So every single time there is a problem on any installation we should be recommending an expensive EICR?
Madness

 

[Pete999]

So every single time there is a problem on any installation we should be recommending an expensive EICR?
Madness

Never said that Mate did I? you're clutching at straws now aren't you? You have noticed the phrase get an EiCR done and jumped to the wrong conclusion, without taking much/any notice as to why I suggested an EICR, need to take what I said in the context of why i said it.

 

[radiohead]

Never said that Mate did I? you're clutching at straws now aren't you? You have noticed the phrase get an EiCR done and jumped to the wrong conclusion, without taking much/any notice as to why I suggested an EICR, need to take what I said in the context of why i said it.

Disagree by all means, but your default position I have noticed over the years is 'get an EICR'....Where I take issue is the notion that an EICR will identify all problems, which seems to be your inference. You need to have a look at the guidance on carrying out EICR's which requires them to be carried out with minimal dismantling, this is because dismantling for inspection is time consuming (cost burden),damaging to surface finishes (unacceptable) and potentially introduces faults that were not there before. Except on very small installations 100% sampling is neither recommended or practical. Bear in mind that 50% sampling (and even that is beyond what is recommended) means 50% of points will not be subject to full inspection by removal, and hence could hide loose connections/local thermal damage. In fact 20% sampling is more realistic which means 80% will not be fully inspected!
And you invariably suggest to the punters on here that an EICR is their golden ticket to perfection.
I ask again. Have you ever actually carried out a full EICR?
The limitations of what an EICR at acceptable cost can identify need to be made much clearer to the paying public.

 

[Lucien Nunes]

Break it down into the main categories and decide which to pursue next:

1. The WM is faulty and sometimes causes excess earth leakage due to water ingress, chafed cables, faulty components. This might correlate with a cycle position, load weight, temperature etc. A maintenance person might find evidence during testing regardless of whether a trip occurs, but intermittents can be notoriously difficult to find. Although I don't like the sound of the Bosch guy's attitude I would not blame him straight off for not finding the problem, as I have spent literally years looking for similar faults.

2. The WM is not faulty but the total leakage on the circuit is high. At a particular point in the cycle or under certain wash conditions its contribution to the total leakage increases and the total passes the RCD trip threshold. It can be complicated to discover the necessary pattern of activities that provokes a trip by experiment due to the number of parameters, e.g. how long since the grill was used and whether the fridge compressor starts during the WM's spin. But, electrical testing could give a reasonable indication as to whether the total leakage is high enough for it to be relevant and worthy of consideration. Note that the amount of leakage is not directly related to the power consumption of each appliance or whether it is switched on. A switched-off PC can leak as much as 100 switched-on heaters.

3. There is an actual fault on the wiring that is being physically disturbed by the WM, e.g. a damaged cable under a floorboard that the machine stands on, that only vibrates when spinning. Pulling the WM out could conceal this problem indefinitely. Visual inspection of the wiring is the only way to rule it out.

 

[static zap]

Was thinking along machine vibration , finding something loose nearby.
(after watching "Ripples" in my washing up water)
..and a very quiet Zanussi.. on spin..
(Exension lead test may actually need other local supply turned off!!)

3. There is an actual fault on the wiring that is being physically disturbed by the WM, e.g. a damaged cable under a floorboard that the machine stands on, that only vibrates when spinning. Pulling the WM out could conceal this problem indefinitely. Visual inspection of the wiring is the only way to rule it out.

 

[GreenGoblin]

Many thanks for all your replies.

OP stated that this is the 2nd Bosch machine that has caused the same problem. A few basic checks of household electrics might be a worthwhile investment, starting with a ramp test of the RCD in question?

I bought the previous Bosch two years ago. It was a smaller 7kg machine. My current one is an 8kg Bosch Series 6. Within three weeks the 7kg machine started intermittently tripping the RCD. The trips were more frequent than the ones I'm experiencing now with this machine. I got the Bosch engineer (the same guy who recently looked at my current machine) to look at it. He ran the electrical, quick wash and spin tests on the machine and checked the sockets. He didn't look inside the machine. He said he couldn't find a fault on the machine (the previous 7kg one) and attributed the problem to the dedicated mains socket that I have for the machine - despite his socket testing gadget showing no faults.
He advised me to put the machine on another socket. I did this and the machine was still tripping. So I was forced to call out another Bosch engineer. He ran the same electrical, quick wash, and spin tests on the machine. It intermittently tripped in front of him while running the quick wash cycle. So he declared a motor fault. This second Bosch engineer also did not look inside the machine.

The brand new 7kg machine was declared faulty so I paid a bit extra and got it replaced with my current 8kg Bosch from John Lewis. My current machine has gone for almost two and half years without tripping. During this time it was connected to the dedicated mains socket that the first Bosch engineer said was "faulty". If my RCD or the power socket was faulty, then surely my current machine would not be able to go for almost two and a half years without tripping the mains. This is why I found it hard to accept the recent diagnosis from the Bosch engineer (who also diagnosed the previous machine).

Is this machine plugged into the same circuit as everything else in the kitchen ('kitchen ring')?

What else is plugged into this circuit? If you could list everything and anything plugged in it would help.

My uneducated gut is thinking cumulative earth leakage tripping the RCD so that next step for me would be to unplug everything and start plugging things back in and monitoring the earth leakage.

I would combine that with a load check on a clamp meter while the machine e does a cycle, just to get an idea of how much leakage there is. It may just be you've got too much leakage and the RCD does its job.

You may find having a separate radial (on am RCBO) for your white goods eliminates the tripping issue

Hi thanks
This morning I decided to find out which circuits my devices and appliances are on. My RCD is only labelled with A,B,C,D and numbers. So it was difficult to figure which circuit breaker is responsible for what.
The big thing I've learned today is that all the appliances in the kitchen (microwave, boiler, kettle, washing machine, and fridge, and a small lamp) are all on one circuit breaker. BUT this is not the circuit breaker that trips. All this time I presumed the circuit breaker that trips was responsible for the machine and all the appliances in the kitchen, but it's not the one that trips.

The circuit breaker that trips covers the following:
Wireless router, 19" flat panel TV, small speakers and subwoofer (all three are connected via a four plug extension and are always on/standby)
BT cordless phone main base unit (plugged directly into a mains socket and always on)
Smartphone charger (always plugged in, but turned off at the mains)
Small decorative lamp with five lights, but only one bulb installed (always plugged and switched on at the mains, but never in operation while the machine is running)
Small DAB radio (always plugged in, but turned off at the mains socket)
A small low power single bulb lamp and BT cordless phone charge station (connected via a four plug extension. Always on at the mains. Phone charge station is always on, lamp rarely used never in operation when the washing machine is on)

That's everything that's plugged into the circuit that trips.

Break it down into the main categories and decide which to pursue next: 1. The WM is faulty and sometimes causes excess earth leakage due to water ingress, chafed cables, faulty components. This might correlate with a cycle position, load weight, temperature etc. A maintenance person might find evidence during testing regardless of whether a trip occurs, but intermittents can be notoriously difficult to find. Although I don't like the sound of the Bosch guy's attitude I would not blame him straight off for not finding the problem, as I have spent literally years looking for similar faults. 2. The WM is not faulty but the total leakage on the circuit is high. At a particular point in the cycle or under certain wash conditions its contribution to the total leakage increases and the total passes the RCD trip threshold. It can be complicated to discover the necessary pattern of activities that provokes a trip by experiment due to the number of parameters, e.g. how long since the grill was used and whether the fridge compressor starts during the WM's spin. But, electrical testing could give a reasonable indication as to whether the total leakage is high enough for it to be relevant and worthy of consideration. Note that the amount of leakage is not directly related to the power consumption of each appliance or whether it is switched on. A switched-off PC can leak as much as 100 switched-on heaters. 3. There is an actual fault on the wiring that is being physically disturbed by the WM, e.g. a damaged cable under a floorboard that the machine stands on, that only vibrates when spinning. Pulling the WM out could conceal this problem indefinitely. Visual inspection of the wiring is the only way to rule it out.

Hi, thanks

I've never had an argument with a service professional before until I encountered the Bosch engineer who recently looked at my machine. I just wanted him to inspect the machine properly and asked him to take the top panel off and check for stray wires, chaffing, see if the drum is catching, etc.
And that's when he flipped. He said he didn't need to take the top panel off as he could see everything through the hole in the back. I asked him several times, and he became sarcastic and invited me to look at the machine since I was the "expert". I declined and I said I wasn't going to pay if he wasn't going to inspect it properly.
At that point he said he didn't need to be in my home. I tried to reason with him and said I would be happy to pay if he would just look at it properly. His body language became increasingly hostile and he repeatedly kept saying "you've refused to pay" and used that as an excuse to storm out.

He shoved the machine back under the worktop and left it unbalanced and unplugged.
He also lied in the engineer's report. He said he wanted to carry out a 15-minute quick wash cycle on another socket. I would have been happy for him to do this, except he actually told me he wanted to run a cycle for over an hour on another socket while he went away. I declined because I wanted him to visually inspect the inside of the machine properly first, something which he said wasn't necessary.
I also noticed there were no readings for any of the electrical tests on his report.
I wrote a long email to Bosch, but they are standing by him and his conduct.
Based on the symptoms I described I was expecting a more thorough inspection of the machine beyond the basic tests. I just didn't expect such poor service from Bosch.

I really hoped to rule out a fault with the machine. I've just discovered today that the actual circuit breaker that trips isn't the one covering the circuit that the washing machine or any of the kitchen appliances are on.

All this time I presumed that the circuit breaker that was tripping was the one that the machine is on (my RCD has no labels identifying which breaker belongs to which room), but it isn't.

I don't know whether this means that the machine is not faulty. Perhaps you are right. The earth leakage is so high from other devices on the tripped circuit and the machine's "normal" earth leakage is just tipping it over.

But from what I've worked out today, the machine is not on the circuit that is tripping. Could the earth leakage from a device or appliance on one circuit cause the circuit breaker on another circuit to trip?

Thoughts appreciated.

 

[Pete999]

Disagree by all means, but your default position I have noticed over the years is 'get an EICR'....Where I take issue is the notion that an EICR will identify all problems, which seems to be your inference. You need to have a look at the guidance on carrying out EICR's which requires them to be carried out with minimal dismantling, this is because dismantling for inspection is time consuming (cost burden),damaging to surface finishes (unacceptable) and potentially introduces faults that were not there before. Except on very small installations 100% sampling is neither recommended or practical. Bear in mind that 50% sampling (and even that is beyond what is recommended) means 50% of points will not be subject to full inspection by removal, and hence could hide loose connections/local thermal damage. In fact 20% sampling is more realistic which means 80% will not be fully inspected!
And you invariably suggest to the punters on here that an EICR is their golden ticket to perfection.
I ask again. Have you ever actually carried out a full EICR?
The limitations of what an EICR at acceptable cost can identify need to be made much clearer to the paying public.

Yes. . . .

 

[Lister1987]

Break it down into the main categories and decide which to pursue next:

1. The WM is faulty and sometimes causes excess earth leakage due to water ingress, chafed cables, faulty components. This might correlate with a cycle position, load weight, temperature etc. A maintenance person might find evidence during testing regardless of whether a trip occurs, but intermittents can be notoriously difficult to find. Although I don't like the sound of the Bosch guy's attitude I would not blame him straight off for not finding the problem, as I have spent literally years looking for similar faults.

2. The WM is not faulty but the total leakage on the circuit is high. At a particular point in the cycle or under certain wash conditions its contribution to the total leakage increases and the total passes the RCD trip threshold. It can be complicated to discover the necessary pattern of activities that provokes a trip by experiment due to the number of parameters, e.g. how long since the grill was used and whether the fridge compressor starts during the WM's spin. But, electrical testing could give a reasonable indication as to whether the total leakage is high enough for it to be relevant and worthy of consideration. Note that the amount of leakage is not directly related to the power consumption of each appliance or whether it is switched on. A switched-off PC can leak as much as 100 switched-on heaters.

3. There is an actual fault on the wiring that is being physically disturbed by the WM, e.g. a damaged cable under a floorboard that the machine stands on, that only vibrates when spinning. Pulling the WM out could conceal this problem indefinitely. Visual inspection of the wiring is the only way to rule it out.

Am sure I covered point 2 ? if the machine has been passed then I'd look at 2 followed by 3 and for belt and braces an EICR ducks and runs for cover

 

[nicebutdim]

Many thanks for all your replies.


I bought the previous Bosch two years ago. It was a smaller 7kg machine. My current one is an 8kg Bosch Series 6. Within three weeks the 7kg machine started intermittently tripping the RCD. The trips were more frequent than the ones I'm experiencing now with this machine. I got the Bosch engineer (the same guy who recently looked at my current machine) to look at it. He ran the electrical, quick wash and spin tests on the machine and checked the sockets. He didn't look inside the machine. He said he couldn't find a fault on the machine (the previous 7kg one) and attributed the problem to the dedicated mains socket that I have for the machine - despite his socket testing gadget showing no faults.
He advised me to put the machine on another socket. I did this and the machine was still tripping. So I was forced to call out another Bosch engineer. He ran the same electrical, quick wash, and spin tests on the machine. It intermittently tripped in front of him while running the quick wash cycle. So he declared a motor fault. This second Bosch engineer also did not look inside the machine.

I'm absolutely not qualified to advise on this issue, but simply wanted to highlight one piece of information that had seemingly been overlooked by others who are qualified. It may be relevant that you have experienced this same fault with two consecutive machines or the irreularity of trips may suggest that it is of no relevance.

 

[radiohead]

Many thanks for all your replies.


I bought the previous Bosch two years ago. It was a smaller 7kg machine. My current one is an 8kg Bosch Series 6. Within three weeks the 7kg machine started intermittently tripping the RCD. The trips were more frequent than the ones I'm experiencing now with this machine. I got the Bosch engineer (the same guy who recently looked at my current machine) to look at it. He ran the electrical, quick wash and spin tests on the machine and checked the sockets. He didn't look inside the machine. He said he couldn't find a fault on the machine (the previous 7kg one) and attributed the problem to the dedicated mains socket that I have for the machine - despite his socket testing gadget showing no faults.
He advised me to put the machine on another socket. I did this and the machine was still tripping. So I was forced to call out another Bosch engineer. He ran the same electrical, quick wash, and spin tests on the machine. It intermittently tripped in front of him while running the quick wash cycle. So he declared a motor fault. This second Bosch engineer also did not look inside the machine.

The brand new 7kg machine was declared faulty so I paid a bit extra and got it replaced with my current 8kg Bosch from John Lewis. My current machine has gone for almost two and half years without tripping. During this time it was connected to the dedicated mains socket that the first Bosch engineer said was "faulty". If my RCD or the power socket was faulty, then surely my current machine would not be able to go for almost two and a half years without tripping the mains. This is why I found it hard to accept the recent diagnosis from the Bosch engineer (who also diagnosed the previous machine).


Hi thanks
This morning I decided to find out which circuits my devices and appliances are on. My RCD is only labelled with A,B,C,D and numbers. So it was difficult to figure which circuit breaker is responsible for what.
The big thing I've learned today is that all the appliances in the kitchen (microwave, boiler, kettle, washing machine, and fridge, and a small lamp) are all on one circuit breaker. BUT this is not the circuit breaker that trips. All this time I presumed the circuit breaker that trips was responsible for the machine and all the appliances in the kitchen, but it's not the one that trips.

The circuit breaker that trips covers the following:
Wireless router, 19" flat panel TV, small speakers and subwoofer (all three are connected via a four plug extension and are always on/standby)
BT cordless phone main base unit (plugged directly into a mains socket and always on)
Smartphone charger (always plugged in, but turned off at the mains)
Small decorative lamp with five lights, but only one bulb installed (always plugged and switched on at the mains, but never in operation while the machine is running)
Small DAB radio (always plugged in, but turned off at the mains socket)
A small low power single bulb lamp and BT cordless phone charge station (connected via a four plug extension. Always on at the mains. Phone charge station is always on, lamp rarely used never in operation when the washing machine is on)

That's everything that's plugged into the circuit that trips.


Hi, thanks

I've never had an argument with a service professional before until I encountered the Bosch engineer who recently looked at my machine. I just wanted him to inspect the machine properly and asked him to take the top panel off and check for stray wires, chaffing, see if the drum is catching, etc.
And that's when he flipped. He said he didn't need to take the top panel off as he could see everything through the hole in the back. I asked him several times, and he became sarcastic and invited me to look at the machine since I was the "expert". I declined and I said I wasn't going to pay if he wasn't going to inspect it properly.
At that point he said he didn't need to be in my home. I tried to reason with him and said I would be happy to pay if he would just look at it properly. His body language became increasingly hostile and he repeatedly kept saying "you've refused to pay" and used that as an excuse to storm out.

He shoved the machine back under the worktop and left it unbalanced and unplugged.
He also lied in the engineer's report. He said he wanted to carry out a 15-minute quick wash cycle on another socket. I would have been happy for him to do this, except he actually told me he wanted to run a cycle for over an hour on another socket while he went away. I declined because I wanted him to visually inspect the inside of the machine properly first, something which he said wasn't necessary.
I also noticed there were no readings for any of the electrical tests on his report.
I wrote a long email to Bosch, but they are standing by him and his conduct.
Based on the symptoms I described I was expecting a more thorough inspection of the machine beyond the basic tests. I just didn't expect such poor service from Bosch.

I really hoped to rule out a fault with the machine. I've just discovered today that the actual circuit breaker that trips isn't the one covering the circuit that the washing machine or any of the kitchen appliances are on.

All this time I presumed that the circuit breaker that was tripping was the one that the machine is on (my RCD has no labels identifying which breaker belongs to which room), but it isn't.

I don't know whether this means that the machine is not faulty. Perhaps you are right. The earth leakage is so high from other devices on the tripped circuit and the machine's "normal" earth leakage is just tipping it over.

But from what I've worked out today, the machine is not on the circuit that is tripping. Could the earth leakage from a device or appliance on one circuit cause the circuit breaker on another circuit to trip?

Thoughts appreciated.

I think you should ask a competent electrician to investigate exactly what is tripping and carry out some tests such as insulation resistance and earth leakage.
Don't listen to the nonsense about EICR's. The purpose of an EICR is to verify the safety and compliance of an entire installation as far as reasonably practical. It is NOT intended as a specific fault finding procedure.
IMO it would be unlikely that a visual inspection of the internal wiring of the appliance would identify a fault, not impossible but unlikely. Whilst from your description the Bosch engineer behaved unreasonably, no tradesman will take kindly to a client telling them how to do their job.

 

[Pete999]

I think you should ask a competent electrician to investigate exactly what is tripping and carry out some tests such as insulation resistance and earth leakage.
Don't listen to the nonsense about EICR's. The purpose of an EICR is to verify the safety and compliance of an entire installation as far as reasonably practical. It is NOT intended as a specific fault finding procedure.
IMO it would be unlikely that a visual inspection of the internal wiring of the appliance would identify a fault, not impossible but unlikely. Whilst from your description the Bosch engineer behaved unreasonably, no tradesman will take kindly to a client telling them how to do their job.

I think you should ask a competent electrician to investigate exactly what is tripping and carry out some tests such as insulation resistance and earth leakage.
Don't listen to the nonsense about EICR's. The purpose of an EICR is to verify the safety and compliance of an entire installation as far as reasonably practical. It is NOT intended as a specific fault finding procedure.
IMO it would be unlikely that a visual inspection of the internal wiring of the appliance would identify a fault, not impossible but unlikely. Whilst from your description the Bosch engineer behaved unreasonably, no tradesman will take kindly to a client telling them how to do their job.

It's not Nonsense Mate, you have mentioned 20& 50% that but have you ever mentioned the correct operation of the RCD? no you have battered on about EICRs the operation of the RCD MAY BE THE ROOT of the problem, you shouldn't as a respected member dissuade the uninitiated to call an EICR "a nonsense"

 

[westward10]

Can we knock on the head the pros and cons of EICRs it is not helping.