Gas Furnace & A/C Tips - Northern climate

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SumpChump

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Just getting ready here for a likely furnace replace in the future. Midwestern house stick built with basement, forced air &A/C setup. The house is 1,100 square feet ranch 25 years old furnace isnt original but is at least 13 years old as well as A/C.
Comfortmaker 9MPseries 90% efficiency rated two stage I guess it's called, nothing fancy 14x20air filter no humidifier or anything else. It natural gas , condensate drain, exhaust PVC power vented out the side of the house.

A. I have no idea how long either a furnace or a/c can or should go. Never had any repairs. Filters replace RELIGIOUSLY. Am I 'living in a prayer' statistically already? Or should I let her go till she croaks. (We live in a small city of 10k with easily accessed HVAC providers)

B. Is it a notably better financial deal/ mechanical idea to have both furnace and A/C done at same time?

C. Have there been any developments in HVAC gear (furnace/A/C) recently that are "hogwash" hot trends which are things to avoid?

D. Any particular manufacturers which aren't what they used to be and are to be avoided?

E. Any manufacturers that are still making a good product with quality computer boards, blower motors??

F. Any other general tips? Such as "when you have it done make sure they....purge.... don't reuse....route...etc. stuff that cutting corners stuff I might not spot without warning.
 
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I am in the Philadelphia area and had my oil burner looked at a few weeks ago. The unit is over 30 years old, on its last legs and my wife has hated oil forever. We are looking at a gas furnace replacement so I am also very interested in tips as well. Hoping to keep the A/C part that is on top. I guess BTU's and efficiency are the buzz words. Local utility has a $300-400 rebate for 95% efficiency installations as I am sure they are top of the line.
 
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I'm not in the North any longer but did just buy a complete new system for my new house. House is 20 years old and everything was original, from my research I think 20 years is about the beginning of the end. With that I decided to just replace it before I move in so I can enjoy it and not have to worry about the unit going out in the middle of summer.

I have a split electric A/C and natural gas furnace. I did some calculations and even here in AZ it didn't make financial sense to pay extra for a higher SEER A/C unit. I didn't even consider upgrading the furnace to a more efficient model since the winters here are so mild. I looked into a dual stage unit, but I didn't find the cost worthwhile.

I ended up with a builder's basic "Day and Night" which is an ICP brand owned by Carrier. Apparently all the companies make several different brands that are all the same so they don't have distributors all selling the same equipment. 10 year warranty on all parts so I figured I couldn't go wrong.
 
Some lucky buggar will will get me as a job sheet. Nice open basement, no doors, no service closet, plenty of open empty space in all directions, a blank canvas. The guys who did my gas powervent water heater 2 years ago mentioned how nice it was to have an un finished basement with no [censored] piled up and well lit. No hedge or deck or fence around the AC unit outside.
 
My gas furnace and AC is 32 years old, about %65 efficient. An upgrade for both units would cost about $3,000 and would probably save me $400/year. It's just on the edge of making sense to do it.

When I go to sell the house it'll look silly to have an old furnace but, the one I have is so dang reliable and I don't trust the new fangled stuff.

I don't see any reason the original poster should upgrade, too much money to gain %5 in efficiency.
 
My furnace is from the (early) 1970's. the burner has been replaced somwhere in the 1980s though. still going strong, though 6 years ago I had to spend a few euro's as the fuel pump coupling (plastic bit) had worn away and last year the non-returnvalve in the bottom of the oil tank leaked so had to take it out and
clean it.

I' using about 400 gallons of oil per year, and a new furnace would costs me thousands of dollars, so even if I only needed half of the oil with the new furnace, I'd need decades to break even. That's assuming the new furnace won't get expensive faults....
 
A 90% unit that's only 13 years old is not (or shouldn't be) on its last legs. A good unit with a quality install should easily last 20 years. There may be some maintenance along the way. Energy savings will be limited since you already have a pretty efficient unit.

Name brand it is less important than a quality install of what ever brand. As was pointed out, the major manufacturers all churn out several brands with very similar if not identical innards so there can be multiple distributors in same area selling similar products under different brand names.

Our 20 year old 80% efficiency Carrier unit churns along just fine. One maintenance call in the last 10 years. The last checkup showed no issues and comments remain to keep doing what we are doing as she looks and runs great, burns clean.
 
A. the air filter you replace for the most part has nothing to do with life span of the furnace (burner or heat exchanger). no you are not living on a prayer, no where close, not with a forced hot air natural gas unit. gas units typically last longer than oil units, and forced hot air longer than hydronic. definition of "live" is failure of the entire unit or such parts that it is not feasible to fix, such as the heat exchanger which is the main thing. the gas burner is trivial. i don't know exactly what you have but you said condensate drain, so the simple thing to do is inspect inside the unit for signs of corrosion.

B. depends on the setup, make/model/brand, and availability or commonality of parts. with a gas furnace you have 2 heat exchangers or coils, one is for heat and the other is the refrigeration coil (evaporator) that's part of the AC. sometimes one can be replaced and not the other, sometimes not. with the ac there's 2 sides to that, the evaporator that's in the blower or air handler that's part of the furnace, and the compressor/condenser that's outside. the condenser if in good shape can be reused, however if it's an R22 unit you may not be able to find anyone to recharge it and you'll be forced into a new R410 AC unit, courtesy of the EPA. http://www.epa.gov/ozone/title6/phaseout/22phaseout.html

C. yeah, R410. if you get condensing type gas furnace, look into quality/warranty/reviews on their heat exchangers. the condensate is acidic and with like everything else, they cut corner on quality of material and the stainless steel heat exchanger is not stainless enough, they corrode and fail. if the heat exchanger is replaceable/servicable then you fix that, otherwise you're looking at a new unit, which new duct work to fit new unit because it's not same exact size, and labor cost associated with that.

D. sorry don't know or haven't kept current on it.

E. same as D.

F. research hvac and teach yourself. it's one thing to pay out for an installer who will give you a warranty up front. real world is another when that installer goes out of business or leaves you out in the cold, and then the next repairman in says i won't deal with that or it's going to cost you. Serviceability designed into how things are installed is something most installers don't do because of time, money, an ounce of brains, or caring about their customer. you didn't mention hot water, so i assume you have a separate traditional gas fired hot water tank which is fine. but for heat/air conditioning make sure your new unit is sized to provide adequate heat, most forced hot air systems fall short especially in condos/rental properties but that's another story. being single story ranch, i assume you have one zone, maybe consider dampers in the ducting is possible to regulate air flow so all your rooms are comfortable or your not dumping heat into unnecessary areas.
 
13 years is not old for a furnace. Mine is from sometime in the 80's (either 1982 or 1987, I can't tell) 80% natural gas. The one next door is the original 1950 oil burning furnace.
 
We just replaced our furnace August 2014 and it was from 88. Now it didn't see near the cold snaps you guys see up north but I figured I'd throw that out there. We ended up going with a 13 seer ac and the 80% efficiency furnace and so far so good. We just replaced the other unit because it was oversized by a half ton and just couldn't cool the house in the south eastern heat. If it weren't for that we'd still have the furnace from 88
smile.gif
 
Our Lennox system was installed 20 years ago when we built our home. There has never been a repair needed, just normal maintenance. I wouldn't even think about replacing it for another 10 years or so.

If yours is a low end, low efficiency builders model then you might look at the numbers and see if it makes sense to replace it. If it's a quality unit then 13 years old is mid-life.
 
We had a newer Lennox forced air system in our first home. The only negative I've ever heard in regards to them is supposedly their parts are proprietary, where other makes/models can interchange more easily. Not sure how much merit there is in that given I never had to repair mine!
 
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