@YorkshireKasa I changed to INNR and Frient Zigbee switches instead.

The TP Links tend to fail after two years, after the warranty has expired sadly.

  @cbc001 Yea, thats exactly what the Kasa plugs did too, externally they look identical so probably the same plugs. And with one of my plugs its not how many times they have been swotched on and off becasue one of mine that failed was operating a lamp in a bedroom that wasnt actually used! Andy the plug still failed, classic rapid on and off. I bet the plug was used no more then about 10 times!

  @YorkshireKasa Its a capacitor failing over time. This causes a loss of a stable DC supply to the relay circuiit causing it to rapidly switch on and off. 

  @cbc001 Ah right yes, so wouldnt have mattered then if it was used or not, just plugged in would be enough :)

  @cbc001 sadly one of my 4 smart plugs was controlling a Heatmiser heating control system .... I suspect its failure was responsible for

frying the PCB .... £1k cost of replacement! 
 

  @JonHM  Ah that sucks, ive not put any of my smart plugs onto anything that was sensative or costly, not becasue what id read about them, just becasue i didnt trust them, but i suppoe i havnt got anything expensive that would benefit from being  on a smart plug of that nature. Did the plug fail then and thats when the pcb went?

  @JonHM Thats horrendous.