Lennox - Help me please

[John Bowman]

Can one of you HVAC wizards look up in your Preston's or Carson and tell me the years of manufacture for this model?

Lennox Model HS9-311-6P

Thanks in advance,

[mnahrgang]

Need the serial number for the age. The model number tells us the size is 31,100 BTU's or approximately 2.5 tons.

Also most Lennox units have a separate sticker that shows the date.

[John Bowman]

Would you believe
Serial #51

[mnahrgang]

Originally Posted by jbowman

Would you believe
Serial #51

According to my notes: "Either the first two or second two numbers are the year, varying by era" So that's not very helpful, unless you want to take that to mean 1951 (but I wouldn't).

Lacking a date sticker I would use common sense and try to make an estimated age give or take 5 years or so. Look at the condition of the unit, any service stickers that might be on it, ANSI dates etc.

Someone with a prestons guide might have more info. But that's all I've got for you. Sorry.

[John Bowman]

Thanks Mark,

I believe the 51 is part of the serial number that may have vanished through the years. Of course the 51 would mean that the unit was manufactured in Columbus Ohio.

I agree that someone with a Preston's or Carson could help me with narrowing down the age.

[William Warner]

Originally Posted by jbowman

Can one of you HVAC wizards look up in your Preston's or Carson and tell me the years of manufacture for this model?

Lennox Model HS9-311-6P

Thanks in advance,

Manufactured in 1978
7.4 seer

Hope you are well John. Good to see you pop in from time to time.

[John Bowman]

Thanks Bill.

That year is fitting for the situation. The couple bought the house almost 30 years to the day and have vigorously maintained maintenance and upkeep of this A/C unit. It is still working and producing as expected for a 7.4 SEER. Performance is unbelievable considering its age.

Best to you and all iNACHI members.

[William Warner]

Pretty amazing.
I sometimes run into one of these older units still functioning almost like the day it was new.

They must have harnessed some of the cold power from the blizzard of that year for this one!