The fault is explained here.
If after clearing the error code the issue reoccurs this suggests you have a intermittent faulty inlet valve.
I would suggest you replace the inlet valve, after checking the inlet hose isnt kinked and the service valve is open.
How did you get on?
No problem, will await to hear back from you.
OK, do let me know if I can be of any further assistance.
The handyman should be able to test the valve and prove its at fault before ordering a replacement by using a multi meter.
Will await to hear back from you.