AEG Lavamat 16810 washer-dryer door/interlock issue E40 error

[AlanH001]

I know it's an old machine but it's worked flawlessly for 20-odd years. However, the door handle broke last week. I got a replacement and fitted it. Because the old one was in pieces, I wasn't 100% sure I'd assembled it correctly, but I'm sure I have as the door goes together properly, the handle seems to be sprung correctly and it fits back in the porthole easily. I have tried a number of different ways to assemble the springs - there is no clear diagram of this model I can find on the Internet - but I'm sure I have it assembled correctly - the latch is the right way around and the springs match the marks on the plastic left by the old springs.

However, the interlock wasn't interlocking - the machine would try to engage the interlock a couple of times then give an E40 error. I couldn't see what was wrong and everything seemed to be OK, so I got a replacement interlock.

Got that yesterday morning but it made no difference!

The door closes but when I switch on and press start, it tries to activate the interlock but does this a couple of times then throws the E40 error - see video. But it does occasionally work - I recorded a video last night to show it not working and it worked, so I started it and did a load of washing. When I tried it after that, it didn't work.

If I open the door and simulate the door latch engaging (using the latch I replaced or with a screwdriver), the machine will operate correctly and starts OK. This tells me it's not the interlock. All I can think of is that it is something mechanical but I've been trying different things all day and got nowhere!

One thing that puzzles me is that using the old metal latch piece on its own works (the interlock engages) but when I close the door with the new handle fitted, it locks in place, so the latch is correctly engaging with the machine body but the interlock doesn't properly engage somehow. This photo shows the latch inserted and the interlock holding it in place until it cools down and releases.

I have tried pushing the door in tighter and pulling it out a bit while it is closed to see if different pressure on the catch and interlock makes a difference but it doesn't. There are no adjustments on the door, hinge or interlock to move anything even slightly.

It does work occasionally but not others, so it does look like a mechanical/interlock issue but I just can't pin it down. Since the machine was working fine up until the door handle broke, it seems unlikely it's the main circuit board or anything else.

Anyone come across this or got any suggestions?

If I can't get it to work reliably in the next day or so, I'm going to have to buy a new machine!

 

[jj4091]

Wrap a bit of thick duct tape around the tip of the latch pin to see if it is not just mating up mechanically properly. Perrhaps you have been sold a faulty one.

 

[Harry Bloomfield]

One thing that puzzles me is that using the old metal latch piece on its own works (the interlock engages) but when I close the door with the new handle fitted, it locks in place, so the latch is correctly engaging with the machine body but the interlock doesn't properly engage somehow. This photo shows the latch inserted and the interlock holding it in place until it cools down and releases.

Are there any shims, or washers that you might have got in the wrong place?,

 

[AlanH001]

Wrap a bit of thick duct tape around the tip of the latch pin to see if it is not just mating up mechanically properly. Perrhaps you have been sold a faulty one.

Good thinking! Thanks for that.

I've just tried a bit of duct tape but small bits get a bit messy. I also tried some layers of aluminium tape, which is easier to cut and mould around the latch but no difference.

I'm assuming it's the leading edge that needs building up if the gate in the interlock may not be being pushed far enough to the right to engage properly. I don't think the other side of the latch does anything but is simply the bit that the interlock uses to stop the latch being opened.

I can't put any tape on the lip of the latch itself as that makes it even more difficult to get it to engage with the plate and stay closed.

I have tried using both the old metal latch and the new one but they look identical (other than some small signs of wear on the old one) but neither fix the issue.

What I can't see is, although it is sometimes difficult to get the door to close without slamming it (which may have been the cause of the plastic handle breaking in the first place), it's difficult to see how this is not also properly engaging with the interlock gate.

I suspect there is something I'm missing about how the interlock works and interacts with the metal latch but I just can't see it at the moment.

I think I'll play with more tape to see what happens.

 

[AlanH001]

Are there any shims, or washers that you might have got in the wrong place?,

No, no shims or washers at all, I'm afraid. When the door is closed, it sits centrally in the porthole, everything seems to have gone together correctly (eg no gaps between the front and rear parts of the door). I did take the glass out to clean when I was waiting for the new handle but there is really only one way it can all go back together so I'm confident it's all OK. I had to partially remove the door seal to get to the interlock but that fits back in place easily. When the door is closed, it all looks like it's all in place properly.

 

[AlanH001]

Well, I was looking closely at how the latch catches on the faceplate and the casing of the machine. Adding the tape as @jj4091 suggested made me realise that although the latch is tensioned by the spring in the door handle, it seemed to me that the spring wasn't that strong and I could see that if the catch didn't engage fully (as it frequently didn't as it didn't stay closed), the metal latch my not be fully pushing the gate on the interlock fully to the right, meaning the interlack couldn't operate properly. Putting any tape on the latch hook made it impossible to get the latch to engage at all, showing it's delicately balanced.

Anyway, although I'm sure I have already tried all the different combinations of the old and new springs, I put the original spring back in and it seemed stronger (but I could be mistaken). However, the first time I closed the door afterwards, it all worked and it felt as if it had been a far more positive engagement. The laundry has been piling up so I took the opportunity to let it run that cycle!

Also, I had wondered if the continual closing/banging of the door had maybe pushed that side of the casing in very slightly and that may have made it more difficult for the latch to properly latch and activate the interlock. There were no signs of any denting or it being out of shape, but I briefly pulled on the inside of the casing - it's pretty rigid but I may have made a small difference.

I'll let you know after this wash whether this is the root of the problem. I currently have a few layers of aluminium tape on the latch but I'll remove them later and see what happens.

 

[AlanH001]

That wash finished and I put on the next load. I'm now sure the door clicked far more positively that it ever has done (than I can remember) so I think that's been the problem all along (other than the handle breaking): the casing had become slightly bent inwards, meaning the latch didn't fully engage and didn't activate the interlock properly. The spring may have been a red herring but I'd still like to know if the new one is weaker.

Since there is no adjustment for any of this (not in the hinge, the mounting to the door, the door handle and catch, the striking plate or interlock), some brute force is all that can be used to realign the latch and the casing.

When I get some time later, I'll look at it again and take the tape off but I'm as certain as I can be at the moment that it is now resolved.

Thanks to @jj4091 and @Harry Bloomfield for your help!

 

[AlanH001]

I think I understand it now. The door was frequently a bit difficult to close so we had to bang it shut. Over the years, this has pushed the panel on the machine in ever so slightly. It has never been noticeable but I wondered if that could have been the issue and pulled it back out a bit - I must have moved it just a fraction - maybe not even a millimetre but that has fixed it and the door now closes with a far more positive click and it fully engages the interlock! So it's only taken the best part of a week and all I've wasted is buying the replacement interlock at about £30 - could have been a lot worse! I wonder if it'll last for another 22 years?

 

[jj4091]

I hope it does last another 20 years for you but if you already haven't you will probably need to fit new motor brushes (.if yours has them) and a new heating element in the future both simple jobs. Keep it going as long as you can, it seems like you have a good one.
And well done.

 

[assuhors]

Have you used the genuine aeg part, sometimes the pattern ones are troublesome.

 

[AlanH001]

Have you used the genuine aeg part, sometimes the pattern ones are troublesome.

Yes, genuine AEG parts. But it's all fixed now and wasn't directly related to the replacement door handle or interlock in the end.