My whirlpool washer keeps stopping and SAYS HF why ?

This would generally mean there is a low water flow. Make sure the water supply hose isn't kinked or that the supply tap hasn't accidentally been turned off. The next area to check is the foreign object filter is clear. On most machines this will be found on the front of the machine right down at floor level. It looks like a round cap with a handle built in. Unscrew this cap, which may be very tight, and remove the attached filter and trap. Clear any debris you find, including the hole that it came out of. Before you take this filter out be prepared for a few litres of water that will pour out when it is removed.
Hopefully either or both of the above suggestions will help. Otherwise it's time to call an engineer!

Rupert
May 2018