Can automatic water feed hum?

Ed2

I'm trying to figure out a hum or vibration that occurs as the system (single pipe steam) heats up. In the first 15 minutes (could be longer), as radiators are starting to heat, the system hums or vibrates and I'm trying to figure out where/why. It doesn't sound like hammering. I wondered if a vent was vibrating, but tapping, putting thumb over vent hole etc doesn't do anything and it doesn't sound like the noise is from a radiator (location). I'e also tried moving radiator shut-off valves, making sure they're all open and that doesn't matter.



But, if I stand by the boiler when the humming is happening, it sound like it is coming from the boiler and, even then, it seems like it is coming from the automatic water feed as (steam) pressure develops. Is that possible? How would you fix it?



The steam pressure is set low. I think cut-out is 1.5 psi.

crash2009

gas or oil

You running gas or oil Ed?  First let me qualify myself, I am not a heating professional, but it looks like I am the only one around today.  I do a lot of reading around here and I have never heard of the hum you are talking about.  I have heard people talk about the oil pump humming.  And the gas valve in my propane grill hums sometimes.  My gas grill is no big deal, (its outside) when it hums I just wack it with the handle of a screwdriver.  I do not recomend you do that to your boiler though.  I would call my service man to come over and check it out.

Ed2

gas

It's a gas fired boiler, single pipe steam.



It was just serviced a couple days ago. Of course, it didn't do it then.

crash2009

Hum

Seems like nobody is hanging out in STEAM today.  Try your question in the GAS or CONTROLS section.

Steve_210

possible relay

can you post some pictures

Jamie Hall

Is it a real

60 hertz electrical hum?  If so, I would suspect something in the electrics of the auto feeder -- as sprinter suggested, possibly a relay or transformer slightly loose.  But electrical hums are very exact.  Can you tell if it is?

Ed2

not electrical

It's definitely not electrical. It's different pitch and not constant pitch- it is fairly constant low pitch then the pitches goes up as it goes away, giving the impression of something vibrating, closing down, and stopping.



Hum isn't a good word for this. Honk? Groan?

Steve_210

can you shut off

the water to the feeder, see if the noise stops.

nicholas bonham-carter

humming

i had a hum from the fan center relay which supplies 24 volts to the boiler controls. i had to rap on it to find the source of the noise. this was in the first 11 mos. of boiler life, but easily replaced.

other sources could be valve chatter in the auto-feeder.--nbc