On Oct 18, 6:32*pm, "Jim Sherman" wrote:
The single handle kitchen faucet never had the hammer until the licensed
plumber replaced the washers to stop a leak. What would cause this to
suddenly become an annoying problem? The plumber is "slow" in returning to
check out the problem. Thanks for any ideas.

imo

the new "washers" in the single handle faucet perhaps allow the faucet
to shut off the water flow quickly & thus trigger the water hammer

the "fix"

either shut off the faucet more slowly, in a controlled fashion
OR
have the plumber add some water hammer arrestors at the kitchen
faucet shut off valves

cheers
Bob