Fault Code Help

Looking for some help with a reoccurring fault code on my 2010 Octavia vRS diesel.

Fault Code

P0135 - O2 Sensor Heater Circuit Bank 1 Sensor 1.

EML has come on three separate times - with no obvious effect to car's performance - and my local independent has cleared the code accordingly all for the same fault as above. First two times was to check whether it would go away (because no issues with car itself) and the last time resulted in a new Oxygen Sensor being fitted.

The new oxygen sensor esulted in a trouble-free fortnight along with a further 1k miles on the odometer but the dreaded EML appeared yesterday after a straight 135 mile run - stop at services for 30 mins - started the car again and the EML stayed on.

My independent has checked for fault codes again and it's the same code as above??

Can someone shed some light on what to look for or what the issue is?? Really appreciate any assistance or guidance on this. I appreciate the oxygen sensor may have been replaced for no reason but I don't want to spend any more unnecessary cash if I can help it.

Edited 7 October, 20169 yr by JDR888