Author Topic: 30 year old furnace  (Read 3100 times)


  • Stubble
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  • Posts: 118
30 year old furnace
« on: December 19, 2014, 06:14:13 PM »
I have a 30 year old gas furnace that heats my house. It's not very efficient though (maybe 40-50% efficient) . A new 80% efficient one cost $1900 installed. We spend $600/yr on gas (furnace is our only has appliance ). Should I pull the trigger and upgrade? We plan on being in the house 5-7 years. If we sold the house , a buyer would ask for a new furnace for safety reasons, etc... I'm not too interested in 95% furnances right now.


  • Bristles
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  • Posts: 390
  • Age: 65
  • Location: Michigan
Re: 30 year old furnace
« Reply #1 on: December 19, 2014, 06:27:03 PM »
Is this natural gas, or propane?

Either way, a 30 year old furnace can be outright dangerous, and $1,900 for a new one is a good price, if that's the installed price. I had my 15 year old furnace replaced in 2005, but that was because it exploded due to a gas pocket. Blew the chimney right off the roof, and into the woods. Luckily the furnace contained itself, and didn't do any damage to the house.


  • Magnum Stache
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  • Age: 39
  • Location: Melbourne, Australia
30 year old furnace
« Reply #2 on: December 20, 2014, 12:05:33 AM »
If if halves your gas bill, then you've got a payoff period of just over six years, and you're planning on staying five to seven years.

From a cost perspective, it's pretty much lineball, but from a safety and environmental perspective (especially considering the existing unit would be 36 years old by then), I'd lean towards replacement.

Then maybe keep it a couple degrees lower to get the bills lower still :)