Looking for furnace info

Dec 15, 2007 6 Replies

I just bought a house with installed oil furnace Lennox model o11 - 140. Serial no. is hard to read but I think is 5873J00215. I'm looking for any info about that furnace like how old can be, output BTU (input is 140,000 BTU/hr) and efficiency. I try to google for Lennox o11 but can't find anything.



Thank you for any help


Ask your favorite local tech when you call him to get the furnace serviced. I don't understand all I know about lummox serial numbers, but I would venture to guess that its long past its normal design service life.

I spoke to guys and they are serviced that furnace for an old home owner, but they didn't know anything about specs.

Please re-read..... its probably long passed its design service life(usually

18 - 20 years)..... just a guess here, but your furnace if probably closer to 35 years old. Manufacturers usually don't support equipment that is more than 20 years old.

Plant# 58 (Marshalltown Iowa?)October 1973.(5873J) definitely a museum piece.

Wow, I'm going to sell tickets to my basement ;) Anyway thanks!

PS. Any suggestions for a replacement? 1600sq to heat with oil.

Get ahold of your friendly neighborhood HVAC company and get quotes. Get three from *local* companies.

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