Furnace running very hot...

... umm
I thought that if I pointed out some interesting observation about the high exhaust temperature, no one would notice what a dummy I was getting a case of the vapors over a perfectly normal furnace.

groundhogy wrote:
You can melt solder with that exhaust temperature

The inner core of the propane candle flame is
light blue, with a temerature of around 1500 C which is 2732 F.
You can almost melt steel with that. What is your point?

You can melt solder with that exhaust temperature

groundhogy wrote:
I just pulled up the pdf installation guide and read this...

Adjust ducting installation to obtain an air temperature rise of 100°F-130°F. Also see air flow check section.

Sounds like you're right on spec, then, with a bit over a 110 degree temperature rise (68 to 180 degrees).

I just pulled up the pdf installation guide and read this...

Adjust ducting installation to obtain an air temperature rise of 100°F-130°F. Also see air flow check section.

Those are after steady state was reached.

The furnace is a 30k BTU

Initial Air temp: 68.5 F
Enclosure temp: 180 F
Duct temp: 165 F
Exhaust temp: 518 F
Final air temp: 82 F

I doubt the fire box is cracked.
This furnace is pretty new. Stuff still looks pretty shiny.


Atwood Model AFMD30111

A common rule of thumb is that 50 degrees C is the point where a person can barely keep their hand on something.
I could not keep my hand on the furnace enclosure.

I have a fluke multi meter with temperature probe.
If you have specific temperature spots you want measured, let me know.
Guess I will do the enclosure temperature and duct air temp?

I will also see if i can find info on the label.

DrewE wrote:
A "normal" thermometer is the right tool to measure air temperature.

While that is essentially true, if the air is flowing out of a metal grate, measuring the temp of the "fins" on the grate gives a good approximation.
If the grate is not metal, the reading won't be as good.....but still not useless.