kid

first it would be best for you and forum members to keep all your posts in the original thread rather than multiple threads.

one can have simple repairs to a furnace this age. the major problems would be a cracked heat exchanger and a blown blower motor. this would make a repair to a furnace this age not cost effective.

I prefer a matched system. you are btm fishing since this is a rental unit. I don't care for either the Lennox or Rheem furnace quoted. You could do better but I understand the choice since it is rental. If money is not an issue, then I would go on and replace the furnace due to its age and just be done with it. You do want to properly weigh all warranty differences.

You will get a better overall price now replacing everything now rather than wait and replace an old furnace at a later date. There is little to no value on old furnaces whether one yr old or five yr old. If your existing furnace was 10 yrs old or less with a problem free history, I would not replace it. A 20+ yr old furnace is an entirely different matter.

make certain you qualify the dealers providing quotes.

IMO

Thanks again tiger, will keep posts consolidated. You dont like the furnaces for what reasons, realiability, efficiency, what? The Lennox dealer, although I am not thrilled with the brand, came highly recommended and has the service contract for the common area HVAC system and has done several of the neighbors units. I have checked his references and BBB. Are these warranties usually transferrable? Thanks