New furnaces much smaller?

[tbm5690]

Your folks did the right thing by going with the minimum efficiency 80% standard gas furnace allowed to be sold in the U.S. today. They are much more reliable due to the simplicity of the components as compared to the high efficiency 96%+ units. The basic 80% units are cheaper to purchase, maintain and self-repair with a trade-off in fuel consumption. I like to use the analogy of a Port Injected, SOCH 1990's engine compared to a 2025 GDI turbocharged engine with variable valve timing, start/stop and cylinder deactivation technology.

You live in a mild climate. In real winter, 80% vs 96% AFUE is a large difference and the increased unit cost is made back pretty quickly in the form of monthly gas savings. Like anything, maintenance is key. I've had absolutely zero issues with my 96% furnace in the past 7 years since it was installed. 2 stages of heat and a variable DC motor fan were game changers. The furnace it replaced was a 94% AFUE unit that was installed for 22 years and still worked, but it was at the point where I didn't want to keep throwing parts at it.

 

[Nessism1]

As I type this, my original 1950 gas wall heater is busy churning out heat. No fan, no filters, just a steel tub built into the floor/wall, with a burner inside. Has an always-on pilot. If the pilot goes out, gas leaks. Don't like that part. Had a gas company tech come in for an inspection, and he said, "That's a good unit. Keep it". Ha ha. A mini split may be in my future some day, but not today.

 

[y_p_w]

As I type this, my original 1950 gas wall heater is busy churning out heat. No fan, no filters, just a steel tub built into the floor/wall, with a burner inside. Has an always-on pilot. If the pilot goes out, gas leaks. Don't like that part. Had a gas company tech come in for an inspection, and he said, "That's a good unit. Keep it". Ha ha. A mini split may be in my future some day, but not today.

It doesn’t have a thermocouple? Even the 40s/50s era furnaces I’ve seen have a thermocouple that shuts off the pilot gas in case of the pilot going out. It can be a real pain to deal with a pilot that flames out. I’ve tried relighting one, and have tried doing it for up to a half hour before I could get it to light because of the safety features. Once my parents were out of town and I was called by a renter to relight it. The tenant said that the local utility was dealing with cold weather and couldn’t get to it for weeks unless it was an emergency. They’ll light it for free, but obviously there was a lot of demand given the weather.

The new one my parents got is pilotless.

 

[y_p_w]

I was at my parents' house when they had the heat on. It's certainly a different sound than the old heater. The old one would have a clunk sound when it started and stopped, and the fan was way different. This one is a bit louder, but I suppose because it's physically smaller.

 

[Touring5]

Furnaces mostly adhere to a standard size for width (depth may and height does vary).

 

[repairman54]

Pilotless unit, either its spark ignition or glow bar. If glow bar keep a spare on hand. They fail without warning sooner or later.
My old camps 95% unit that I installed new had glow bars, had 2 fail in 10 years. They don't fail in July either.
I also put a surge protector in on it to help keep the main board alive after one surge blew its protection fuse. I got lucky there as more likely than not when the fuse blows so does the board. Rural area with lots of surges.

 

[Exhaustgases]

Old 1970's gas furnace vs new furnace story.

House we sold about 5 years ago had the nice simple old furnace. I think during its time it may have had a newer valve and blower motor installed. Worked great, never a problem.

Next door neighbor had their old one replaced I'm guessing around 2006 or so, they had problems with the new one all the time, I'm thinking 3 years later or maybe less, it was replaced, it had cracks in the heat exchanger. That replacement had lots of electric control issues, etc. In the end before we left they had gone through 3 new furnaces.

Just saying.

Oh the good old days when not everything was equipped with a printed circuit board and a micro processor to function.
I've known more people with bad circuit boards in their furnaces, and what's bad is when there are none to be found, then you get to freeze. Yeah just crazy.

 

[nickaluch]

You live in a mild climate. In real winter, 80% vs 96% AFUE is a large difference and the increased unit cost is made back pretty quickly in the form of monthly gas savings. Like anything, maintenance is key. I've had absolutely zero issues with my 96% furnace in the past 7 years since it was installed. 2 stages of heat and a variable DC motor fan were game changers. The furnace it replaced was a 94% AFUE unit that was installed for 22 years and still worked, but it was at the point where I didn't want to keep throwing parts at it.

I have the same system from Trane 10 years no issues and yes a game changer with comfort and energy savings