Furnace Question

[page2171]

When do you decide to replace a furnace rather than fix it?  I have a 28 year old Bryant natural gas furnace that the tech says needs a new heat exchanger.  Repair is $400 plus labor.  Replacement is $4000-$5000 installed, depending on the model I choose.  Thoughts?

[daddo]

I think 30 years is enough. Replace it.

It has seen the children born and gone through college and now seeing the grand kids born. Give it a break.  

[JosephP]

Not an HVAC contractor, but we just went through this.

Ours was 27 years old.  Tried to fire, but didn't blow.  I assumed it was a blower problem.  Called repair guy and said "I know we need to replace it...but don't want to have to jump to a decision.  If we can pay $300-400 to keep it going and wait a little longer to pay $4000-5000 to replace it in the coming months, let's do that".

He looked at it and said, more like $600-700 to repair (needed new board) vs. $3000-4000 to replace.  That tipped the math enough that we just replaced.  FWIW, I did the math and a 90% efficient condensing furnace looked like it would take 7-10 years of savings over an 80% efficient furnace to pay the difference.  Plus extra holes in the roof.  Plus higher maintenance costs (if I understand correctly).  We went with the 80% furnace so that made the replacement less expensive.

I think it comes down to how that math works out and how often you want to be without heat.  I'd say you gotta be thinking replacement with a unit that old...but does that happen now or later.  For me, once I've decided it is time to replace, I am done repairing.  But periodic repairs doesn't automatically mean replacement.  $400 in repairs every year, and you still have a 10 year payoff for the new furnace.  Maybe that buys time to save the money to pay cash for the replacement and/or shop around...

[brianwelch]

We just went thru this as well...35 yo furnace, 33 yo central AC. Decide to bite the bullet and go new, 96% HE Trane unit. Had to core a 6" hole in the foundation wall (18" stone) for concentric ventilation/exhaust. $600 rebate from power company. Fingers crossed that this unit last as long and be as issue free as our last unit.
Good luck with whatever decision you make.

[fredhargis]

Replace it, the old furnace has outlived it's life.

[Snipe Hunter]

A new high efficiency furnace will be cheaper to operate if that helps sway you. $4000 to $5000 sounds pricey.

How old is the A/C?

Oh, and.. My standard answer for HVAC questions is "Ask Blackhat"

[fixtureman]

I have a different opinion I think you should replace the heat exchanger as the new furnaces will have electronic boards that seem to fail.  Sometimes old tech is better then new.  and the savings isn't going to be enough to justify the cost.

[page2171]

I think 30 years is enough. Replace it.

It has seen the children born and gone through college and now seeing the grand kids born. Give it a break.  

Pretty close...based on the serial number, the furnace was made right around the same time my wife and I started dating and our oldest is through college. 

[page2171]

A new high efficiency furnace will be cheaper to operate if that helps sway you. $4000 to $5000 sounds pricey.

How old is the A/C?

Oh, and.. My standard answer for HVAC questions is "Ask Blackhat"

So, the tech showed me 4 options for new furnaces and I narrowed it down to 2.  First option is $3800 installed.  It has similar features to the one I have now, but more efficient and the addition of the new one being a two stage.  Second option is $4800 installed.  It is a "smart" furnace and, from what I understand, has the capability of varying just about everything to achieve peak efficiency...fan speed, first and second stage length, etc.

A/C is 6 years old.

[fixtureman]

I would rather have a dumb furnace as you don't know where the tech stuff will be in 5 years.  Just try and get a vcr or a tape recorder today