Question from: Richard from Sherwood Park, AB -----
I own a 30-year-old bungalow. The problem I'm having is the pipes in the ensuite make a rather loud knocking noise but only when hot water is going down the drain. I have two other baths where this is not an issue. Ditto for the kitchen sink. If you have any suggestions it would be greatly appreciated.
Your problem is a fairly common one especially with bathroom basins because we tend to run very hot water down the drain when shaving, etc. The noise is normally caused when the hot water comes into contact with the ABS plastic or copper drainpipe causing it to expand. When the pipe expands, it can rub against the back or side panel of the vanity causing the noise. Next time this happens, identify the location and enlarge the hole around the drain or supply line water pipe.