I have noticed there is a similar thread, but the situation is different enough for a new thread.
I have an old house (90y) with an old furnace (22y?) that is connected to hot water heating system. I was recommended to repair a few things (boiler valve (all three) and bleeding valve) that runs ~$1300, and suggested to consider total replacement.
The cost or buying and replacing (there is no way I can DIM) depends on efficiency of the furnace, and 80%: ~$7300, 83%: ~$7900, 90%: $12000, 95%: $17000 (and $1500 return).
I am looking into staying for 5y or so, and the heating cost is low because I don't spend time at home (~$500 at most). If the energy efficiency of the current furnace is ~65%, I would save 75$ each year. If I just repair what I have, it would cost me $1300+$150x5 (maintenance fee)=$2000, so even buying the least energy efficient one does not make a lots of sense to me.
(Plus I secretly think keeping old car or old furnace to the end of the life is greener than buying a shiny new one...)
BUT: I am not taking into account additional maintenance fee that could be needed in future, and an old furnace could hurt the selling price of the house when the time come.
Any suggestions? Opinions? Experience?
I also like to know if the quote I was given is reasonable one.