I have had an X10 system now for 4 years, with about 30 LD11 DIN rail dimmer modules installed. Some of these have started playing up - the problems are that when I switch on using momentary swich of via X10 command a module may briefly illuminate the light, but then the light goes out and stays out.

Second problem is I am finding some modules will come on during the night

Third Problem is that another module flashes - the lights are on and have been on for some time, then they will go out and come on fraction of a second later, then go out a few seconds later and this repeats. Switching off via momentary switch and leaving for a few minutes can often solve the problem, but not always.

The LD11 Unitls are installed int eh loft which is hot in summer and cold in winter.

I've tested that no rogue X10 commands coming from anwwhere. I've ruled out surges on the momentary switch feed wires because one momentary switch connects to multiple LD11's (this is so I can switch them all on or off) quickly at a wall switch yet gain individual control Via X10 commands to do mood scene lighting), and the problem will affect juts 1 LD11 out of the several connected to the same momentary switch circult.

I'm starting to think the issue is simply failure of theses LD11's - has anyone got any similar experiences or suggestions on what to do.

I have ordered some spare LD11's to try swap out, but this could be an expensive way to sort it goinng forward with 5 units on the blink just now after only 4 years!