Before you recommend i use the search function, I have and no topic here (or on other LR forums) seem quite to fit the bill as to my problem.

When I opened the disco this morning to load up the clan to go to a kids sports club function I noticed the passenger door didn't unlock with the central locking.
Cue several attempts to get it working correctly to no avail including the dash door unlock.
No sound of the actuator working either.
Once we got to where we were going I did a quick search and found out about the commonly failing actuators and thought fair enough, I'll order a new one when we get home and fit it next week.
Once we'd left the function the same thing happened to my door! I had to disable the alarm with the remote, open it with the key then lean over and open the passeger door manually.
Once home I had a job to do on it anyway as part of the deep cean I had been doing around the engine bay and todays job was to clean up the battery and battery.
Once the battery had been removed and that and the bay had been cleaned I replaced everything.
Lo and behold the passengers door lock now worked!

I now suspect the issue may be with the recevier unit but think it is better to seek some advice first.
So, has anyone here had this kind of central locking randomness, and what did you diagnose it as in the end? Also, if it is the receiver and I order a new (or Fleabay) one, are they all the same or do they require calibrating/pairing with your remote fob?

Any guidance would be much appreciated.

Hi, it just seems odd but it isn't... the door latch actuators are usually the same age and when they start to fail they can fail even all 5 within one week or just one and other next year, or god knows how cos there isn't a clear pattern, at the beginning the behaviour is intermittent and mainly on unlock command as the work is harder for the mechanism to unlock than lock...as long as only one is working and all the others dont the receiver is ruled out as it receives/sends only one signal to BCU then the BCU manages the central locking...if you'll ever have problems with the receiver there will be no activity in the doors whatsoever...but as a matter of fact the receiver is plug and play and not as expensive imo to not get a new one cos it's not very easy to replace

put your ear or a stetoscope near the actuator when you lock/unlock and if you hear any weak sound then you need a good one cos even a wiring issue is not the case as the signal to the actuator comes on the same two wires to lock/unlock by changing polarity...simple as that

Cheers. The passenger side amde no noise at all when not working which is why I was sure the actuator had failed. However the drivers side still makes a noise but just won't open.
I'm going to go with a used part for now as I also need to get a new fuel pressure regulator as mine has a slight leak and I need to get that sorted first.