This Old House Spring Edition - Plumbing Noise and A/C Service

May 14, 2019 6:52 AM

Two questions: - What is that beached-whale groaning noise that my cold water pipes make when the cold water is turned on? (Video with audio inside) What can I do to solve it, or is this a call a plumber now situation? - I'm getting mailers from service companies I've previously used to install things chiding me to do A/C maintenance. My system is going on it's second year now - are these maintenance service calls needed?

The noise is heard on the first four seconds of the video (here. Click the audio button to unmute. You can ignore the high pitched noise, which is my HE washer letting the water in. The groaning noise happens whenever toilets are flushed, sprinklers come on, or showers are taken.

I've tested the water pressure coming out of the hose bibb and it seems under normal limits. I've also tried shutting off the cold water valve at various times which will stop the noise in its tracks but doesn't resolve it when the water is back on.

For the A/C maintenance - I change the filters myself regularly but not sure what else an A/C technician will be doing and whether it's necessary, having grown up in households where my parents never ever called A/C servicemen...except when the A/C broke.

posted by Karaage to Home & Garden (4 answers total)

The groaning noise is an interaction between loose pipes in the wall and turbulence in your water valves causing the pipes to resonate. It's annoying, but is typically otherwise harmless. If it never happens except when turning the water on or off or while running a faucet without fully opening the tap, that's almost certainly the problem. One thing that can exacerbate the problem is if your main shutoff valve isn't fully open. It might be worth finding it and checking if only so you are familiar with it in case of a pipe break in the future.

If you are changing your filter regularly, there isn't a bunch of buildup on the coils in your indoor or outdoor unit, and you aren't having any specific problems, you have no need of AC service.
posted by wierdo at 7:51 AM on May 14, 2019 [2 favorites]

I believe in preventative maintenance on something like an A/C unit. A decent checkup will clean the evaporator coil inside your air handling unit. Buildup of dust and grime on the coils will decrease efficiency and could also allow mold to build up. The tech will also check the refrigerant level and pressure. If that's low that also leads to problems like an iced-over coil.
posted by JoeZydeco at 9:00 AM on May 14, 2019 [1 favorite]

Water hammer! Our plumber just fixed ours in no time flat.
posted by lokta at 12:13 PM on May 14, 2019 [1 favorite]

In an old house I lived in that noise was caused by bad washers in the faucets and was an easy fix.
posted by SLC Mom at 3:02 PM on May 14, 2019 [1 favorite]