Both indicator lights off on Pulsacoil 2000 - is this a problem?

Last night our Pulsacoil 2000 started making a constant buzzing noise and we noticed that both of the indicator lights are off. We’re not sure how long these lights have been off for, or if we’ve ever seen one of them on in fact. The noise has stopped and we’re still getting hot water as normal.

We don’t know if the instructions in the picture mean that if both lights go off, we should call someone out, or if we only need to do this if the boiler stops working too. 

Does anyone know if  the fact that both lights are off is something to be worried about or not?

“Or if both lights out” - i’d say yes, that means a fault. BTW I have a BoilerMate OV, so no experience of Pulsacoil.