Help with age of Armstrong furnace

Model LUF80C84/95D16
Serial # 8405E00422

Leaking Carbon monoxide @ 18PPM at registers

May 05 80% efficent, oil fired.
It could put out 85,000 or 97,000 btu depending on the nozzel size.

You spelled nozzle wrong.

Armstrong is owned by Lennox. With Lennox it would be May 2005.

The first two no. are the plant, 2nd two are the year, the letter in 5th slot the month.

3 years old and spewing carbon monoxide Thank you for your help.

I have a grandaughter who’s 1 and some of the gases coming out of her are amazing, :shock::frowning:
I’m so proud!:D:D:D

Congradulations Grandpa! does she take after grandpa?

Very unusual to get readings out of the newer furnaces, even if the the heat exchanger is cracked…due to the induction motor, which lowers the pressure in the exchanger and makes it much more difficult for the gases inside the exchanger to mix with the air blowing around the outside of the exchanger. Was the induction motor working or had it’s safety been tampered with? Chimney pluggged? Massive heat exchanger failure??? Curious, if you find out…