motor noise in hot water heating system

Old 08-22-04, 01:26 PM
Visiting Guest
Posts: n/a
motor noise in hot water heating system

I've got a house with a hot water heating system. Lately it's developed a humming sound in the pipes - it's the sound of the water pump, but it seems to be transmitted by the heating pipes, so that it's more noisy in other parts of the house, than it is around the boiler itself. We already had the pump replaced to try to solve the problem, but it only helped for a few days. It seems that fiddling with the pipes or the valves will temporarily eliminate the motor hum, but it always comes back. It's like it's resonating in the pipes themselves. Any ideas or suggestions?
Old 08-23-04, 09:55 AM
Homer Simpson
Visiting Guest
Posts: n/a


Pump hum can be acerbated by a number of factors, hanging a pump to the
floor joists with plumbers tape, incorrect pump for the piping application, mounting it to a wall, etc. All pumps hum and since metal pipe connects to
the pump, the sound is transmitted through the metal pipes. Like listening
for a train by placing your ear to the track.

You may have have always had this hum and only recently noticed it and it
sticks in your mind like jingle from a commercial.

What make and model pump?

Basically, the only real way to prevent the transmission of hum is to have
an acoustic break between the pipes and the pump. Put short section of broomstick on the pipes and your ear to the broomstick, you should hear the hum good and loud. Say goodbye, Homer.

Last edited by Homer Simpson; 08-23-04 at 10:09 AM.
Old 08-30-04, 08:27 PM
Visiting Guest
Posts: n/a
pump noise in heating system, cont'd...

Heya Homer;

The pump I've got is an Armstrong Astro-30B. It's a brown grapefruit-sized cylindrical pump. It's installed with a rubber gasket on both ends between it and the pipes, but there's still metal-to-metal via the bolts that hold it in place. It's most definitely the pump noise I'm hearing, and it's most definitely louder than it once was. The noise level comes and goes, but I've gotten it to abate somewhat (at least temporarily) by putting foam pads under the pipes in the baseboard heaters in various rooms. And I got it to stop once by loosening some brackets where the pipes had been bolted to stud walls in the basement. But eventually the sound always builds up again in volume [ Doh!!]. Could it have something to do witha settling house - perhaps a pipe is put under stress somewhere inside a shifting wall? Or could it have anything to do with a faulty valve on top of the little pressure tank connected to the water lines? That seems to dribble water sometimes, rather than releasing air as I believe it's intended to do...


Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: