I'd suggest turning off the main water supply and opening EVRY faucet in the entire house and flushing every toilet. This includes outside faucets, and the washing machine. Then turn the main back on and with all water running, start shutting off fixtures, starting at the lowest point in the house first, and working toward the uppermost. This should bleed air from the pipes and hopefully solve the problem. iF it persists, I'd follow the advice from the previous post and install after-market water hammer arrestors. Good Luck.