My furnace is barely working AND it's making a whining noise.

Lost_in_Jersey

Good Morning,

My gas furnace, a snyder-general gas fired forced air furnace, is barely heating the house; cool air is coming from the vents. I am relying on a gas fireplace at the moment to prevent a sudden drop in temperature.

Additionally, when I woke 25 minutes ago, I heard a whirling, whining, ethereal jet-engine type noise coming from it.

Does anyone know what is wrong with my furnace?

Snyder-general (snydergeneral?) serial number D893231056

Thank you for your time.

Marty S.

Check the motors. You should be able to tell which one is making the noise after taking the top door off.

hvac5646

You have a vintage Arcoaire furnace of 70% efficient bracket. Rither spark or HSI ignition.

It is over 20 years old.

So your problem is either the blower bearing are going, blower wheel is rubbing against metal or your burners have become so corroded that the gas passing thru them is whistling.

how

I never see a faulty motor/bearings/belt or fan cage cause cool air to blow through the ducts on this type of furnace unless the cool air is just from a fresh air supply just dumping into the return air. These part failings would causing a limiting out with slow air temp 30 -50 F hotter than normal above the plenum and beyond..

As with the advise already given...
Open up the furnace doors and the noice will show you what the problem is.
Let us know what you find..

hvac5646

The blower will run slower and the heat can build up in the ht ex and the furnace will ride the limit.

The furnace will never keep up and the air will be a lot less hotter on the limit trip ...

Family business has dealt ICP all the way back to the time it was Snyder General in the 80's.

how

[quote=hvac5646;854346]
The furnace will never keep up and the air will be a lot less hotter on the limit trip ...

A furnace that rides the limit just runs at 200F instead of 150 to 170F.
I still don't get how a 30 to 50F degree increase in exchanger temp in an atmospheric furnace coupled with no or less fan speed will end up feeling like "cool air in the vents". In my experience it brings neutral temp air at the further perimeter vents with unusually hot air exiting those vents above the furnace like a chimney.

hvac5646

Inadvertent grammatical error...

Point i want to make is the air won't be up to the the usual supply temp. The air might be expressed as being cooler, as the feel of air to any individual is subjective.

Get me?