Slimline storage heater has blank user interface screen. How do I resolve?

Applicable to models:

XLE050 XLE070 XLE100 XLE125 XLE150

TSRE050 TSRE070 TSRE100 TSRE125 TSRE150

NLSH050 NLSH070 NLSH100 NLSH100 NLSH125 NLSH150

DESE050 DESE070 DESE100 DESE125 DESE150

SSHE050 SSHE070 SSHE100 SSHE125 SSHE150

VASH050E VASH070E VASH100E VASH125E VASH150E AC6550 AC6554

Issue: User interface/ display screen is blank. No text displayed.

Action: If confirmed supply OK a service visit will be required with User Interface UI and Charge controller ACC- See link below.

Require additional help? Please follow link below