Hi. Welcome to JA.
The water hammer has probably damaged the water inlet solenoid. That is the only part that could be effected by the water hammering.
What you need to do is install a water hammer arrestor on the outlet at the wall.
The water inlet repair procedure is on page 33 of the service manual.
Please click here to download a copy of your units service manual.
Please advise if you require further information or assistance.
Ok let me know how it turns out.