Habitation door keeps unlocking itself

Hi Everyone
Bought a brand new Burford Duo from Nick Whales dealers  in July (2020). Took it to France in August where the Harmony panel died and we lost all 12v stuff. Truma panel was playing up too. Just what you need a thousand miles from home!
Anyway, managed to get the van back home and over to Nick Whales. 
Just after the 12v failure, the habitation door started to mysteriously unlock itself whilst we're in the van. Doesn't happen if we leave the van and lock it with the keyfob, but once inside and locked manually, it starts over. If we leave it unlocked, it 'thunks' every three minutes as if it's trying to unlock itself even though it's already unlocked.
I sleep on the bed next to the door and this 'thunking' is so loud it's impossible to sleep. 
If we lock the van whilst inside using the keyfob, the habitation door stays locked but continues to 'thunk' every three minutes, with the associated noise. The internal movement detectors haven't kicked off whilst we tried this option, but I'd be worried they might in the middle of the night.
The only way to prevent this happening seems to be to leave the ignition switched on; but that is clearly unacceptable.
Nick Whales have had the van for five weeks, brought out Mercedes to look at it, the alarm people and consulted with Autosleepers but still can't fix the problem. They've upgraded software, put in new cabling and god knows what else, but nothing has worked in solving the problem so far.
We're pretty much at the end of our tether with it, which is a great shame because it is a lovely motorhome, but not one that we can use I'm afraid.
Just wondering if anyone else out there has experienced this issue, and if so, how did you fix it?
Many thanks

We have exactly the same problem with our 2020 Bourton, and have just come back from Autosleeper and had a “patch” applied to the Mercedes electrics. But the door “clunking” still persists whether locked or unlocked.  I noticed some “metal terminals” at the bottom of the door on the hinge side which appear to connect some sort of electric circuit in the door. I have placed insulating tape over these terminals to prevent a circuit when the door is closed!  Hey ho ....   we had a quiet nights sleep last night ....   hooray!  However it does mean we have to lock the door with the manual key rather than the fob as it will no longer lock electronically .....   small price to pay!!   Obviously the electrics are not right and we are talking to our dealers next  week! By the sound of your experiences it’s going to be a long haul to get to the bottom of the problem. Hope this helps!!

Hi waggysenior and cath
Welcome to the forum from Bridington 
Boaby

Hi Burlingtonboaby; thank you for your kind welcome.
Hi Cath; thank you for your response. I think if it wasn't for the earlier failure of the EC700 I'd probably live with this 'fix' and just get on with it, despite the £86k price tag. However, there's another posting on this forum about these issues which go back to early 2019, and a number of owners who are still without satisfactory resolution.
It has totally undermined my confidence in the MH and AS, and given we were planning adventures as far away as Norway, I'm struggling to reconcile the 'risk' of subsequent failure. When our EC700 died in France there was absolutely no support from AS or Mercedes (understandable). Our UK dealer did their best and sent a new panel out to us which I had to install (not a good DIY'er) but for this price tag I expect this stuff to work as it should.
The MH is back at the dealers again and this time, I've put them on notice that if it can't be fixed, it's being rejected as not fit for purpose.

Hi WaggySenior,

I feel your pain. Had same dealer - we experienced poor customer service over similar issues and frustrations with a 19 Bourton.

Eventually, dealt with AS directly, who listened to us and were good - customer service as it should be. Our issues were eventually resolved and currently all seems to work as it should.

See this thread - it may help https://www.autosleeper-ownersforum.com/t30453-2019-bourton-mercedes-electrics-issues

Hi LDPD
Thank you for your comments. Yes, I've read the whole thread from your link; quite unsettling isn't it. Glad that you're sorted now and I am hoping Nick Whales will get it right this last time; but I'm not holding my breath. What is remarkable is that they clearly didn't bother to test the 'repairs' they'd made, or they would have realised straight away that the problem persists. Or perhaps they did and were hoping I wouldn't notice? We'll see.

Waggysenior wrote:Hi LDPD
Thank you for your comments. Yes, I've read the whole thread from your link; quite unsettling isn't it. Glad that you're sorted now and I am hoping Nick Whales will get it right this last time; but I'm not holding my breath. What is remarkable is that they clearly didn't bother to test the 'repairs' they'd made, or they would have realised straight away that the problem persists. Or perhaps they did and were hoping I wouldn't notice? We'll see.

Totally agree with your assessment which is why we went direct to AS

Just realised (and read through)  SIX pages of the same problem manifesting itself from early 2019, without proper resolutions!  oh dear .....

Hi Cath
Yes, I read it all as well. I think a long haul is an understatement. Anyway, I hope you manage to get your Bourton fixed.

There is a software update by Mercedes which doest fix much of this. If you have a third party alarm ie Autowatch, A/S and maybe Mercedes (connot remember if Mercedes said this as well) said it needs to be removed.
There is now a new rewiring requirement/fix that A/S need to do. Our van is in with A/S for this and a many other issues (again).
Ths latest change to be made is now standard on all new 2021 Mercedes based A/S models. The solution (I know its a poor solution) is to REMOVE the habitation door from the central locking side of the vehicle. You then have to use the key to lock/unlock from outside (and remember to lock manually when inside. I dont know how true this is, but heard that another manufacturer using the latest Merc Sprinter has also had to do this.

We have a 2019 Bourton on Mercedes running gear  and for 14 months we suffered much on the failures of the Auto Sleeper and Mercedes  systems which is really no comfort to anyone as the problems still seem to persist 2 years down the road of the motorhome faults on new builds.
You would think that Auto Sleepers actually spend time trying to sort the fundamental problems out before selling any more, or replace the (dis)harmony system with something more reliable and simpler to use.

However having disabled the habitation door power by isolating the power contacts at the front bottom of the door, adjusting the run time of the steps, isolating the steps from the auto extension on the key fob, having the EC unit replaced and updated, the list is quite extensive.

I recently had to take the “Haunted Snail “ to a Mercedes  commercial vehicle for upgrades and I was informed that they could alter the automatic self locking and anything else  that is so frustrating with the Mercedes bits.
So badly designed and I’ll thought out in the minor details on the Bourton ie tooth cup holder position, habitation door handle or drawer positioning stupid little things that are avoidable if the designers actually spent sometime thinking through what they were trying to achieve .
It would be nice if the cab seats fully rotated as well. Perhaps they might now as one of the recall checks carried out was the rerouting of the under seat cables. 
Hey ho just got to find somewhere to go now.