Swap 91% with 95% furnace burner myself?
Here’s the situation – the rear of the downstairs has a 90+ efficiency (condensing) Carrier gas furnace, professionally installed in 1993. The Carrier 4-zone system (new at that time) was a constant problem. In 2002 or so, the four-zone controller and all sensors and thermostats was replaced by my HVAC guy with a generic aftermarket version, with new motorized dampers and all. That part works fine.
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However – the furnace draft fan and burner has always been sensitive – cold nights, windy nights, it often will shut itself down, gotta manually restart it – yadda – yadda. HVAC guy’s gone over it with Carrier reps several times, replacing vacuum switches, checking for intake/exhaust obstructions . . . but nothing lasts for long.
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So –
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1) How hard would it be to just replace the burner section of the furnace with a new 95% efficiency unit, leaving the A-coil alone? It’s maybe 8 years old, the fan motor maybe 5.
2) Could I get the tax credit if I install it myself? Homeowners can do their own “component replacement†and gas “re-connections†here.
3) Any recommendations on brand? The 4-zone apparently works downstream, and is independent of the burner section.
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Forrest
Replies
Bump
Forrest,
Two years ago I installed Amana 2-stage furnace. My buddy got a great price on Ebay. 96% effy. The old unit was 80% 125KBTU/hr and the new unit is 48/70K. Great furnace. I definitely recommend "down-sizing" the furnace -- far better than oversizing. Two stage is the best.
You can do it! You have to be able to do sheet metal work, electrical & instrument wiring, PVC plumbing, and threaded gas piping. If you are comfortable with these skills, then go for it.
I suspended the a-frame and upper plenum with a few screws. Then I had to jack up the furnace with shims to reattach.
It became particularly satisfying when I was able to donate the old (only 2 years old) furnace to my disabled cousin who lost his in a flood. Timing was perfect!
I did it. So did my brother in law. Niether of us have had any problems..
Once you do your own you can much more easily repair the furnace should anything ever happen..
Carriers can be quite sensitive to intake and exhaust vent piping.
It's gotta be by the book, or else it won't work right... or at all.
If you are talking about just the burners and hx instead of the whole furnace, can't be done.