Brief whistling sound only when furnace starts up

lbeachmike

My mom has a Carrier 58CVA135---1--22 furnace. She tells me that there is a whistling sound that comes from the furnace when it first starts up. From what she describes, it sounds like it is coming from the vicinity of the blower box.

I am not nearby her house but will be there tomorrow to take a first-hand look. I want to be prepared to try to address it is if it is something simple, or otherwise investigate further.

Any ideas? Thanks.

JUGHNE

Plugged air filter, old filter sucked into blower etc.

lbeachmike

It only makes the whistling sound at startup. Then runs normally.

kcopp

combustion on the burner may need adjustment. Only good way to do that is w/ a combustion tool.

lbeachmike

kcopp said:

combustion on the burner may need adjustment. Only good way to do that is w/ a combustion tool.

This would cause a whistling sound that happens only at startup?

EdTheHeaterMan

I have found that HVAC equipment, that makes humming or whistling noises are usually the ones that forget the words. Have you tried placing the sheet music in plane view of the furnace?

lbeachmike

EdTheHeaterMan said:

I have found that HVAC equipment, that makes humming or whistling noises are usually the ones that forget the words. Have you tried placing the sheet music in plane view of the furnace?

Lol. Thanks for the laugh. Was this only intended for humor, or are you also saying that it is likely not of any concern?

STEVEusaPA

Isn't that just the model number for the cased coil?

EdTheHeaterMan

I used to keep my customers in stitches with comments like that. It had nothing to do with the sharp sheetmetal edges I left on their ductwork

lbeachmike

STEVEusaPA said:

Isn't that just the model number for the cased coil?

I will double-check.

lbeachmike

STEVEusaPA said:

Isn't that just the model number for the cased coil?

Looks like it is actually Model 58CVA. I'll update the original post. Thanks!

EdTheHeaterMan

That whistling noise on "Start Up", can you be more specific? There are several "Start Up" items that you might be referring to.

On a call for heat, the thermostat will "Start Up" the combustion fan for something called pre purge.
After the combustion fan is proven to be operating the next step is ignition where the gas valve opens and the gas flame will "Start Up."
Once the flame is established the control will then make the Blower "Start Up" to move the air thru the ductwork.

I'm thinking the whistling is from the last item I listed. That makes the most sense and is not a real problem. It is just the way some air is leaking thru a small imperfection in the ductwork or poorly fitted blower door. If the noise is annoying then some one can try to locate the source and plug up the imperfection with sealer or duct tape. If it doesn't bother anyone, then I would just forget about it