Rheem 90 plus furnace

[Burl]

My daughter and her husband have moved into a house that has a Rheem 90 plus gas furnace, looks to be in good condition, from the numbers it was made (and I assumed installed) in 1994. It works well and heats the house. They are thinking of replacing it, due mostly to its age. Anyone know of how well these are built and how long do they last? I know major appliances are usually a crapshoot, how about furnaces?

 

[bonneyman]

Most Rheem furnaces I'm familiar with had a 20 year warranty on the heat exchanger. A 1994 model would expire at 2014.

But that's just the warranty. Kept in good running order and no leaking condensate pan you could go longer than that. have a reputable heating contractor come out and inspect it. more than likely they'll try and sell you a new unit, but you might find an honest guy and he might get you a few more years.

 

[larry4406]

me - I would continue to run it until it quits, while keeping the money for replacement squirreled away for when the time comes. Make sure the home has operable CO/smoke detectors in the event the heat exchanger has a pinhole leak.

Maybe pay $50-100 to have the unit professionally inspected to assess the condition of the heat exchanger, etc.

I don't have any long term experience with Rheem furnace, but I did put one in a detached garage that I built, but I only enjoyed it for about 4 years and we sold and moved.

 

[Jackfre]

Planned replacement is a good idea. that way they can mange the change-out and study the issue of what to replace it with. When it is cold as it has been in the east this year trying to find a good guy to do the job in Jan is tough...and expensive.

 

[yeldogt]

If properly sized with good flow they can last a long time -- much depends on installation and operating temps. Cold operation and restricted operation kills most of the unit not done in by a leaking AC evap.

I would not replace a working unit in good shape ... living in the house will give them some insight on the operation so they have better sense of the proper size needed. Most heaters are oversized and don't run long enough .

 

[Burl]

If the furnace should get replaced, it will be in the upcoming summer/fall when it is not used, and probably by my SIL and myself as a project. I installed my gas furnace in my gas-converted house many years ago and its not rocket science, as said you just need good advice about sizing, etc. How do you know what is the correct size?

 

[yeldogt]

If the furnace should get replaced, it will be in the upcoming summer/fall when it is not used, and probably by my SIL and myself as a project. I installed my gas furnace in my gas-converted house many years ago and its not rocket science, as said you just need good advice about sizing, etc. How do you know what is the correct size?

do a room by room heat load ...... manufacturers have responded and now make lower output units. Modulating w/ VS fan is the way to go if you have cold winters ... longer heating season.

 

[u3b3rg33k]

Also remember that if you install the same size unit but at a higher efficiency, you are actually installing a BIGGER furnace.

I have a two stage now and there's no way i'd go back to single stage. 2 stage or VS for sure.

 

[rharman]

We had two Rheem 90's installed when we remodeled in 1993. One was replaced several years ago and the other is still going strong. Had to replace a Hot Surface Ignitor once and that's about it.

 

[sammyslab]

Hi Burl. This is my first post and as it happens, we built a new home in 1994 with a Rheem 90+ gas furnace installed. We sold the home in 2015 with only one with the furnace in all those years and that was the failure of the small motor/fan that pulls air thru the heating tubes. I know there's a name for it but just don't recall. We had a technician check it out every year before the winter season, clean it and replace any parts that were needed. It was a 150K BTU unit if my memory serves me correctly.. The only issue that I had was that the unit produced a LOT of WATER! And I mean a LOT!! It didn't have a sump pump like the new ones do which helps. It would freeze and back up into our unfinished basement. Good luck!!

 

[mygarageone]

I am a Rheem dealer , keep your furnace maintained .. It will last for yrs to come.

A yearly clean and check does wonders.

By the way , if and when you buy a new unit . Go with a single stage with the variable speed motor energy saver.
The more bells and whistles , the more issues you'll have to deal with later on and your additional savings won't cover the up front cost of the xtra's .

 

[Burl]

I am a Rheem dealer , keep your furnace maintained .. It will last for yrs to come.

A yearly clean and check does wonders.

By the way , if and when you buy a new unit . Go with a single stage with the variable speed motor energy saver.
The more bells and whistles , the more issues you'll have to deal with later on and your additional savings won't cover the up front cost of the xtra's .

If we replace this one, what model do we get? Same BTU?

 

[u3b3rg33k]

If we replace this one, what model do we get? Same BTU?

you should probably downsize - remember:
100kBTU @ 90% = 90kBTU supplied
100kBTU @ 95% = 95kBTU supplied

so a more efficient furnace is actually bigger. that also means it needs more airflow, so if you don't downsize a little you could run into issues if your ductwork isn't awesome (hint: 99% of homes don't have awesome ductwork).

also the calculations for sizing furnaces have a built in "fudge factor". when contractors size a furnace, they often add 20% (or so) as their own fudge factor (if they bothered to do math at all), and then you end up with a furnace 40% bigger than you needed in the first place, all because someone didn't want to put one in that was too small.

without knowing any info about the house/gas bill/heating degree days, it's probably safe to drop down to an 80k, and if it were my house and I was buying blind, I'd go for a 80k 2 stage - stage 1 would consider something like the goodman GMEC96 0803BNA - an 80kBTU 2 stage 96% efficient furnace.
that will give you 77kBTU of heat on high, and 54kBTU on low. low being half the size of your old furnace means you'll get longer runtimes in mild (and cold) weather, which means less cycling (contributes to longer life of the furnace, and more even temps in the home), and because airflow is dependent on BTU output, stage 1 will be nearly silent. I barely hear mine run on stage 1.

and remember: you buy insulation once, you buy gas every time the furnace turns on!

 

[mygarageone]

Forget Goodman , Please . But the fact that most duct work isn't sized properly , is the reason you want the ecm motor . They adjust the fan speed to the duct work . It eliminates a lot of air flow issues.
Over Sizing a hi eff furnace is the worst thing you can do ! It will. Help shorten the furnace life quickly.
Who ever you get to do a new unit , make sure they do a basic heat load for sizing .

There are several good furnaces out there but I do not consider Goodman to be in the running for quality . I consider Goodman a 10 yr furnace .

 

[Showkey]

Not to get too far off topic........Since furnace sizing generally comes in round numbers like 40k-60k-80k-100k and Efficiency in 90-94-96% worrying about 3k BTU increments is pretty Much ridiculous.

The sizing change often comes in play when going from 80% efficiency to 90+% so 100k 80% is often resolved with 60-80k depending on climate, original size, insulation and over heat loss.

As far Goodman this forum has a love-hate thing going on for years now and there is no shortage of Goodman haters willing to bash Goodman at a moments notice. Sometime I think it’s because Goodman often supplies their complete product to the DIY market so a DIY guy can install a unit at huge savings if they have the knowledge and skills or hire an independent contractor for the install.

Back to the OP .........I would run the current furnace until it tells you it’s time for replacement with excessive high cost repairs. Many of us are keeping 20+ years old 90+ plus units alive with normal maintenance and reasonable price priced replacement parts often DIY.

 

[Burl]

Back to the OP .........I would run the current furnace until it tells you it’s time for replacement with excessive high cost repairs. Many of us are keeping 20+ years old 90+ plus units alive with normal maintenance and reasonable price priced replacement parts often DIY.

There is the rub. It only takes a few (if that many) repairs to make someone replace an appliance of any kind, much less a furnace. When you have to call a tech on a Saturday night when its 10 degrees outside to replace a part that would cost you $25 online and it now costs you $200 is when you think of replacing. You can do without your fridge for a few days, heat not so much.

 

[Showkey]

True ^^^^^^^^but $200 for igniter replacement even on the weekend has a better ROI than $10-12k for a new HVAC unit ..........especially if the older is still in good shape and just needs a repair part. All industries sell new as the answer like a car needs a brake job, alternator and then a exhaust......so it gets traded in because it’s too expensive to repair but the new car payment is $600-700 a month for 5-7 years.

 

[u3b3rg33k]

Forget Goodman , Please . But the fact that most duct work isn't sized properly , is the reason you want the ecm motor . They adjust the fan speed to the duct work . It eliminates a lot of air flow issues.
Over Sizing a hi eff furnace is the worst thing you can do ! It will. Help shorten the furnace life quickly.
Who ever you get to do a new unit , make sure they do a basic heat load for sizing .

There are several good furnaces out there but I do not consider Goodman to be in the running for quality . I consider Goodman a 10 yr furnace .

I've heard hearsay on ECM motors visiting an early grave when they're installed on undersized ductwork (compounded by allergy grade 1" filters).

my point with downsizing was that getting another one of the "same" isn't actually getting another one of the same - most ducting i've seen (including my house) is very marginal or just plain bad, so upsizing by a little bit with a newer unit that has tighter operating tolerances can be the difference between the old one just working and the new one having nuisance shutdown issues.

Goodman isn't the only brand made by daikin - just look at the cabinets (goodman, amana, heil are three). there's more than a few brands that look "exactly" the same...

Not to get too far off topic........Since furnace sizing generally comes in round numbers like 40k-60k-80k-100k and Efficiency in 90-94-96% worrying about 3k BTU increments is pretty Much ridiculous.

The sizing change often comes in play when going from 80% efficiency to 90+% so 100k 80% is often resolved with 60-80k depending on climate, original size, insulation and over heat loss.

As far Goodman this forum has a love-hate thing going on for years now and there is no shortage of Goodman haters willing to bash Goodman at a moments notice. Sometime I think it’s because Goodman often supplies their complete product to the DIY market so a DIY guy can install a unit at huge savings if they have the knowledge and skills or hire an independent contractor for the install.

Back to the OP .........I would run the current furnace until it tells you it’s time for replacement with excessive high cost repairs. Many of us are keeping 20+ years old 90+ plus units alive with normal maintenance and reasonable price priced replacement parts often DIY.

install quality is a HUGE factor in system reliability. the furnace isn't a stand-alone system - the filter, ductwork, venting, leveling, having a drip leg, cleaning up the shavings from threading pipe, etc are are all important factors.

 

[zmaxmotorsports]

I am a Rheem dealer , keep your furnace maintained .. It will last for yrs to come.

A yearly clean and check does wonders.

By the way , if and when you buy a new unit . Go with a single stage with the variable speed motor energy saver.
The more bells and whistles , the more issues you'll have to deal with later on and your additional savings won't cover the up front cost of the xtra's .

 

[zmaxmotorsports]

I've got no problems with Goodman equipt,they've come a long ways since the Jani junk days.
Most of it comes down to installs it.
I'd say I've come across more junk trane wreck/carrier/Lennox installs in the last 20 plus years than Goodman in a 50 mile radius of Omaha anyway.
As far as selling to anybody who walks in off the street the only supplier we have currently selling Goodman is Johnstone supply,good luck buying from them if you're not a licensed contractor.
As far as on line suppliers anybody can buy pretty much anything from them,including trane wreck.

 

[mygarageone]

I've got no problems with Goodman equipt,they've come a long ways since the Jani junk days.
Most of it comes down to installs it.
I'd say I've come across more junk trane wreck/carrier/Lennox installs in the last 20 plus years than Goodman in a 50 mile radius of Omaha anyway.
As far as selling to anybody who walks in off the street the only supplier we have currently selling Goodman is Johnstone supply,good luck buying from them if you're not a licensed contractor.
As far as on line suppliers anybody can buy pretty much anything from them,including trane wreck.

I think some day internet heating sales to the DYI is going to bite them in the **** . First time some guys burns or blows up his house do to a improperly installed product , a law suit will ensue.

 

[Showkey]

I think some day internet heating sales to the DYI is going to bite them in the **** . First time some guys burns or blows up his house do to a improperly installed product , a law suit will ensue.

Same way internet sales of welding equipment and someone burns their house down.......or sun burns his eye balls because using sun glasses as a welding helmet.

Or

Home Depot home owner sales of water heaters and the house floods or burns or CO poisoning.

Or

Oreilys Auto parts selling brake parts to DIY that then fails to stop and runs into the neighbors garage door or worse.

Or

Lowe’s for selling circuit breaker box to DIY guy. Or maybe the ceiling fan that falls on someone’s head.

Or

advance auto parts for selling a fuel pump to a DIY guy who then burns the house down.

Think tire stores should stop selling tires to regular customers ? I mean there are dozens of install problems and blow out at 80 ........think of the law suit

HVAC have been restricting the market place for years.........it’s surprising they have not been sued for restainted or unfair trade and pricing practices.

The auto manufacturers found themselves on the other side of the law suit when they restricted fair trade in the repair, parts and service information network. They lost and were forced to supply the aftermarket and DIY with service information, test and repair protocols and full scan tool access to the aftermarket.

 

[Burl]

True ^^^^^^^^but $200 for igniter replacement even on the weekend has a better ROI than $10-12k for a new HVAC unit ..........especially if the older is still in good shape and just needs a repair part. All industries sell new as the answer like a car needs a brake job, alternator and then a exhaust......so it gets traded in because it’s too expensive to repair but the new car payment is $600-700 a month for 5-7 years.

No chance I would pay $10-12k for a new furnace. If should be able to buy a replacement for this furnace for under $3k (wholesale) easily. Like I said, installing it is a weekend project.

 

[yeldogt]

I am a Rheem dealer , keep your furnace maintained .. It will last for yrs to come.

A yearly clean and check does wonders.

By the way , if and when you buy a new unit . Go with a single stage with the variable speed motor energy saver.
The more bells and whistles , the more issues you'll have to deal with later on and your additional savings won't cover the up front cost of the xtra's .

I'm a bit surprised by this ... I prefer simple when it come to boilers and water heaters as I don't think the savings is worth the upfront costs and these is no comfort gained. but the modulating and staged furnace and HP/AC units really do deliver a comfort level that can't be achieved with single stage equipment. I personally have been using them for about 15 years w/o issue ... I'm sure things do go wrong ... but my understanding is the gas valves are reliable.

 

[yeldogt]

I think some day internet heating sales to the DYI is going to bite them in the **** . First time some guys burns or blows up his house do to a improperly installed product , a law suit will ensue.

I'm really surprised that pre-charged flexible hoses have not moved into the mini split world. Being able to order lines in various lengths would be a game changer -- the vast majority are installed where accurate length can be determined.

There is nothing any more dangerous installing vs selling an oven .. and the overall savings in electric vs window units is large. Modern auto type hose has a useful life exceeding 20 years ...

 

[aunsafe2015]

I'm a bit surprised by this ... I prefer simple when it come to boilers and water heaters as I don't think the savings is worth the upfront costs and these is no comfort gained. but the modulating and staged furnace and HP/AC units really do deliver a comfort level that can't be achieved with single stage equipment. I personally have been using them for about 15 years w/o issue ... I'm sure things do go wrong ... but my understanding is the gas valves are reliable.

What's the comfort benefit of a variable stage furnace? Simply less temperature fluctuation?

I know that a variable stage a/c reduces temp fluctuation AND helps with humidity. But I've read that most of the comfort benefit is the reduced humidity, which can also be achieved by just adding a dehumidifier to a single stage system...

 

[ripperd]

What's the comfort benefit of a variable stage furnace? Simply less temperature fluctuation?

I know that a variable stage a/c reduces temp fluctuation AND helps with humidity. But I've read that most of the comfort benefit is the reduced humidity, which can also be achieved by just adding a dehumidifier to a single stage system...

Variable stage furnace, when heat load is lower, will turn down the firing rate AND the fan speed. So the air coming from the registers is coming out much slower, eliminating the cooling effect of the air movement. Or if you compare to a poorly adjusted furnace, the hot blast!

 

[u3b3rg33k]

What's the comfort benefit of a variable stage furnace? Simply less temperature fluctuation?

I know that a variable stage a/c reduces temp fluctuation AND helps with humidity. But I've read that most of the comfort benefit is the reduced humidity, which can also be achieved by just adding a dehumidifier to a single stage system...

Think of it another way - what's the benefit of a variable throttle in your car? just convenience?

single stage - full throttle or nothing?

2 stage - off, 2/3 throttle, and full throttle?

or do you want the right amount of throttle for what you need, when you need it?


FWIW I once drove a car home in "single stage" mode. the MAF failed so it only had static maps and the O2 sensor to run on. basically it would idle and it would go WOT, but nothing else. well guess how much fun THAT was?

 

[yeldogt]

What's the comfort benefit of a variable stage furnace? Simply less temperature fluctuation?

I know that a variable stage a/c reduces temp fluctuation AND helps with humidity. But I've read that most of the comfort benefit is the reduced humidity, which can also be achieved by just adding a dehumidifier to a single stage system...

As others have said -- it's to match the needed load. It's one of those things that until you live in a house with such a system it's hard to convince someone that it's worth paying extra.

The systems are extremely quiet because they ramp up and down all day based on the load -- they never fall way behind like a conventional system. On set back they can also ramp based on outside temp and how you set the system for recovery. It's very rare to have them running on high except on the extreme outside temps. Some systems have stages -- others are infinite .... same with blowers.

The staged AC and HP's offer more than humidity reduction -- it's the same thing in reverse. The inside fan runs very low all day -- and the compressor ramps up and down to meet the load. They make zoning very easy -- I zone all my projects.