Bosch Maxx7 WM, stops with F17 twice a cycle at the same point

[olaybolx]

I have a Maxx7 Washing Machine that is about 4/5 years old.  A few months ago it started stopping during a wash with an F17 error.  Pressing the start button the wash continues until the end.  Then it started happening a few times a wash, bringing the temperature down to 20 from 40 degrees lower the number of times the F17 appeared but it is still very annoying. 

So after researching the error codes I checked the water inlets, not blockages, filters not blocked, water pressure seemed just fine.  Replaced inlet valve, replaced pressure sensor and even changed the heating element (probably should not have listened to that advice).

Anyway, none of it made any different.  I have also put bi-carb and vingear in the machine to wash out as the water here is pretty hard.  Now here is the weird part, when the machine is run empty and at 40 degrees it runs through the wash without issue.  I have no idea where to go on this.

Any help would be really appreciated.

Cheers,

Gary

[Whitegoodshelp (Andy)]

Hello Gary. Unfortunately the error codes that I have access to do not feature F17. The highest goes up to F16. As you found replacing parts just in the hope that it will fix it is often a waste of time and money. It sounds like a difficult fault to diagnose without any specific reference to what F17 means. But if it is only doing it on the wash cycle then it is usually related to heating the water in some way. But it could be an electrical fault causing the heating element not to get any power, or a neutral fault on the heating element side, or a faulty sensor, or faulty connection to the sensor. It could even be something unrelated that is triggered when the washing machine gets hot and something expands. Unfortunately it's just not practical to try and DIY repair something like this. You need an engineer who has had experience with this fault before and has the correct meters to test things and even may have parts in his van that he can try and put back if it doesn't make a difference.

[olaybolx]

Andy, Thanks for the reply.  I think I know why you are not familiar with the F17, I am living in Germany where the machine was bought and the fault numbers are different.  The F17 is a problem with the water pressure or the water filling.  This is not the problem, I have cleaned the machine, I have opened the drawer as the water was filling and the amount and pressure look fine.  I think it's a sensor type problem but I am not sure which one.

When the error comes, I click the Start button again for the machine to continue, it does and the action taken by the machine when I press start is for water to start running through the drawer and into the drum.  It runs normal then for the next 30-40 minutes until the same issue happens again.  I click start, water starts flowing and the machine finishes without further problems.  

The weird things are that it does it only twice on 20C temp wash, does it more on 40C temp wash.   It also does it more if you put too many items in the wash (large/full wash).  And then the opposite, without anything in the wash it runs through the wash without any problems regardless of the temperature.

Maybe the control board or whatever it's called is bad?  Or maybe there is another sensory that might be causing this.  If any of this suggests something I would value your opinion, If not I guess I will have to get a technician out.

Cheers,

Gary

 

[Whitegoodshelp (Andy)]

It's not losing water down the drain due to siphoning is it? Washing machine fills and drains at same time 

These might be useful How a washing machine controls water levels  | Faults on pressure system

[olaybolx]

Hey Andy,

So I sat and observed the machine when it errored out.  Seems to me like the water gets pumped out, (I checked and the water was flowing out) but the pump runs for about 8-10 minutes at which point it seems to time-out with the F17.  Clicking on Start and the machines finishes without problems.  

The question I have is, is how does the machine know when all the water has been pumped out?  Is there a sensor or does it just run on a timer.

Cheers,

Gary

[Whitegoodshelp (Andy)]

Hello Gary. Your question is answered in detail on the last 2 links on my last post. 

[olaybolx]

Thanks Andy.  I missed the third link on the pressure system.  Sounds like it might be a good place to investigate.

Gary

[Whitegoodshelp (Andy)]

Hello Gary. Yes if the washing machine pumped away the water perfectly okay, but then carries on pumping it and eventually cuts out with an error code there is a good chance it is because the pressure system has not received a signal that the water has gone. In the vast majority of cases this is due to a buildup of gunge and grease inside the plastic pressure chamber bottle. I have had reports of many people replacing pressure switches and not one of them has ever said that it fixed the fault so be cautious about replacing the pressure switch.

[olaybolx]

Hey Andy, well like the good sheep I already replaced it to no avail.  It wasn't take costly to try compared to getting someone to come and take a look at it.

I think there is a good chance it's the pressure chamber, things seem to add up to it.  I'll take a look this weekend.

Thanks again Andy.

 

[Whitegoodshelp (Andy)]

Thanks for the update, and honesty. It's helpful to others. Fingers crossed.

[olaybolx]

Hey Andy,  Update on my washer.  I took all the hoses from around the drain pump out and washed them.  To be honest they were not as dirty as I would have thought and there were sadly no blockages.  

I reassembled and ran the machine empty with a bottle of this special washing formula to clean your machine out.  Ran with no issues but that has never been a problem when it's been empty.

On the first real load at 40C the errors were still present and at the same point in the cycle.  On the second load, at the point where the drainage pump runs for nearly 10 minutes I disconnected the pressure switch.  The machine completely stopped showing 21 minutes on the timer.  I plugged the switch back in, the time jumped back to 26 minutes and the machine continued to the end without the F17 error.

I am baffled as to where the problem is.  The pressure switch was a replacement so is fairly new.  Where else could the problem lie?  Could it be something electronic?

Cheers in advance.

Gary

 

[Whitegoodshelp (Andy)]

Hello Gary. Yes if you've already observed that water pumps are okay, but the problem is that it carries on pumping (nothing) then it can't possibly be a fault on the pump, or a blockage in any of the hoses to and from the pump. Any such a blockage would stop the pump from emptying, or reduce its flow capacity to an extent that it timed out on empty because it wasn't emptying fast enough. But a previous post of yours describes how it pump the water okay but just carried on pumping for no reason for a further eight minutes. Therefore the only possible blockage that could cause that is a blockage in the pressure system.

Such a blockage is described in detail in the links I put up previously including how to check for it by gently blowing down the pressure tubing. If it isn't anything to do with the pressure system being blocked (we've already established it's not the pressure switch because a new one made no difference) then I can't honestly think of anything else to suggest. I certainly would not speculatively change the PCB, which is always a big risk.

[olaybolx]

Hey Andy, the pumps seems to be working just fine.  I disconnected the pressure switch, blew down the tube earlier so it is not a blockage.  The PCB change is costly and no guarantee it will fix the issue.  I think I might just have to live with it until the wife complains too much and we have to buy a new one.

Gary

[olaybolx]

Hello Andy,

    Listen, I wanted to follow up with you regarding my problem as it is now fixed and maybe my information can help someone else.
The wife wanted to buy a new machine but we can't afford the best part of 1000EU so after seeing how good a condition that machine was still in and not wanting to replace it I called Bosch.  99EU for them to look at it, if they repair it then the fee is waved.
Anyway, it was to do with the incoming water.  While the pressure was OK the flow rate was greatly restricted.  As I didn't have the experience to know what was enough and what was not enough it didn't register with me that that was the problem

I have attached the part that was replaced.  It's a part I cleaned from underneath but didn't think the inside was all clogged up.  Little did I know.

Anyway, thanks again for all your help.

Gary

[Gokhk]

On 28/03/2020 at 19:41, olaybolx said:

Hello Andy,

    Listen, I wanted to follow up with you regarding my problem as it is now fixed and maybe my information can help someone else.
The wife wanted to buy a new machine but we can't afford the best part of 1000EU so after seeing how good a condition that machine was still in and not wanting to replace it I called Bosch.  99EU for them to look at it, if they repair it then the fee is waved.
Anyway, it was to do with the incoming water.  While the pressure was OK the flow rate was greatly restricted.  As I didn't have the experience to know what was enough and what was not enough it didn't register with me that that was the problem

I have attached the part that was replaced.  It's a part I cleaned from underneath but didn't think the inside was all clogged up.  Little did I know.

Anyway, thanks again for all your help.

Gary

Thanks very much kind sir you've given me am idea to diagnose my own problem with a washer dryer.