P16CB $07E8. P16C1. $07E8

I have a 2016 Octavia 1600tdi (49,000) from new.

recenty the mil has come on and the code

P16CB and P16CI . Indicating the rear aux heater pump fault I’ve replaced this unit but the mil light come back on eventually but no set pattern, I can drive for 2/3 hour one day and no problem and then comes on the next day after driving 1/2 mile. 
Even when the light is on there is now power issues, drives like a dream. Will I do any harm if I continue to drive the car for the next two weeks as a local diagnostics centre can’t book it in
Any ideas