Knocking noise in sewer pipe Home › Forums › Public Forums › Drainage & Sewerage › Knocking noise in sewer pipe This topic has 1 reply, 2 voices, and was last updated 24 years, 1 month ago by SylvanLMP. Viewing 1 reply thread Author Posts 8 Jul 2000 at 6:54 pm #278592 Anonymous We live in a mobile home and when we flush the toilet in the rear bathroom, the pipes knock in the front bedroom. Is this a sign of plumbing problems? 9 Jul 2000 at 2:55 am #298811 SylvanLMPParticipant Have some one check the supports horizontal. Make sure they are not swinging in the breeze good luck Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In