Corsa 1.3 CDTI 08 plate EGR Problems - DieselMan1966

Hi bit of a weird one, recently the EML light has been flickering on and off, done the Vauxhall pedal trick and had the diagnostics done with flagged up the EGR valve.

The service agent suggested trying the Terraclean, which improved everything, and extra 5mpg!. everything was ok until the light came back during the hot summer, again the diagnostics flagged up the EGR, decided to change it at the next service.

However as the weather turned cooler and I began to use the heater, the light since I have been using the heater. This could be coincidence though.

Does anyone know if this is the sign the EGR cooler is beginning to fail as I believe these are water cooled, its done 120k, serviced every 5k and not use any low quality diesel