Which gas furnace would you recomend?

[muck]

First of all, thanks for all the imput on my last question.
I am about to get bids on having a new gas furnace installed. What would be your choices?
Location: Minne-so-cold
House: Walk out rambler built in 1985.
Size: 1700 square feet each floor.
Construction: 2by6 walls, new Marvin windows.
My age: 54
Age of present furnace: 1985, was put in when house was built. Rheen 90% rating.

I am not looking for some high tech super efficent furnace. I had an A.O.Smith SureShot gas water heater put in, which is "state of the art", and it has been nothing but problems. The installer even replaced it, but it just went out again recently.
My present furnace has never needed repair, but at 20 years old, it's time to replace it before I retire.

[tinner73]

20 years and no problems. why change brands? Rheem is still good.

[docholiday]

muck, sorry for your bad luck with the AO smith waterheater but it really is a different beast. I agree water heaters shouldnt be that complex and AO smith would probably not be my first choice either.

Put the Rheem mod in. It does have complicated computer stuff in it and yes it too is a 90+ but the comfort is unmatched (not simply a 2 stage vs, but a modulating furnace that matches its output to the current conditions of the home. Really its about as close to any wet heat comfort as you can get in forced air.

Its got a standard 5 year warranty on all parts but if your at all afraid, spend a couple bills on a 10 year parts and labor warranty and not worry about it for a decade. Dont take my word for it, ask around here or find someone who has it and ask them.

[BaldLoonie]

I just came from a house we put a Mod in earlier this winter. I still marvel at that furnace. So incredibly quiet when loafing along at 40% but still putting out toasty hot air.

If you want just a basic furnace, the 90Plus is still may favorite. Reliable, quiet and easy to service.

[Irascible]

If you don't mind me asking Baldie, has any OEM come up with an answer to the Mod? I haven't bothered checking into the current Infinity system (I'd rather jam toothpicks under my fingernails than become a Carrier dealer), so I don't know a lot about it. But I don't think it does anything along the lines of what the Mod does. From what I can tell Infinity is an elaborate "your ducts suck alarm system".

[BaldLoonie]

Every mfr has 2 stage with variable speed blower but nobody has gone beyond that.

[docholiday]

Originally posted by Irascible
From what I can tell Infinity is an elaborate "your ducts suck alarm system".

Hahaha thats funny

I get the same feeling... Yeah there are some neat communication things but theres got to be more than that to it, I just cant figure out what. I mean doesnt everyone offer some sort of dehum capabilities and VS?

[Midwest]

muck - just a quick question for the water heater portion of your problems. Is there a water softener in the same room? We have found that they reak absolute havoc on flame sensors due to the salty corrosive environment created when they flush. Discovered the cause after a troublesome new Surshot kept giving up in a new home down the street. We didn't install, but owner asked us to try to solve the problem. He isolated the water heater from the softener and all has been well for over two yrs. now.

Water softeners can ruin the hell out of 80% furnaces, their HX's and cause flame sensor problems over time, too. It's that corrosive & salty atmosphere. If that isn't the case, well you're one step closer to finding what may really be the culprit- cross that one off the possible causes list. Greg

[41gasman]

Irascible.
Your comment about the
"your duct work sucks alarm"
is just to damm funny to be
legal! It so true it hurts.
I still get "nerves" when
I'm sizeing on retro fits
because of all the lousy
ducting that hase been done
around here.It is either
down flow into undersized
duct into the ever classic
spider web of poorly installed
flex. Or its upflow in a closet
with 8'x20' return directly behind
the furnace and 5'up to a couple
of 12'x12' grill in the stairwell.
on a four ton system mind you!
supply goes up maybe two feet
into a "t"feeding a 8"x12" or
if I'm lucky 8"x16" trunk line
going to either side of the house.
The only little problem with the
V/S motors is they WILL ramp up
and push the air.And that when
that "little" alarm goes off.
You know the one that tells the
home owner DUMB GUY,DUMB GUY.
BAD BAD hvac guy.:>}

[Irascible]

[framehvac]

Amana or American Standard

[muck]

You are correct sir. The water softener, water heater and gas furnace are all in a 5' by 10' room. And our water here in Plymouth, MN, is very hard, so it runs a lot.
I will also be moving all three to the other side of the house when the furnace gets replaced to get them out from under the bedrooms, and place them about mid way in the house.
At that time I will take your advise and separate the water softener by putting a wall around it and away from everything else.
Thanks for the great advise.

[alkiir]

I personnaly would reccomed a 2 stage eighty percent furnace. The cost of a 90 is so high, and it takes on average twenty years for it to pay for itself. The pvc pipe will probably have to be replaced to get the right pressures for the exaust and combustion air. If you have a flu allready there, get a rheem or carrier eighty percent 2 stage variable speed. I promise you will not be dissapointed. The only down fall of having a a 2 stage is the cost of the variable speed blower motor if that ever goes bad. They are pretty pricey. You have the same motor though in 90 percents.

[klyons20]

I prefer a properly installed furnice.. I shill dont have faith in the 90 afue furnaces yet. The water will get to it in the end.

regards,
kelvin

[tinner73]

Originally posted by klyons20
I prefer a properly installed furnice.. I shill dont have faith in the 90 afue furnaces yet. The water will get to it in the end.

regards,
kelvin

he said he has a 20 year old problem-free Rheem 90%+ now.

[RoBoTeq]

HOLY CRAP!

You have a 1985 Rheem condensing furnace that has lasted? Not only stick with Rheem but try your damnest to get the same installer.

Not just Rheem, but all manufacturers of condensing furnaces in the 80s had issues. Rheem simply had a few more than I'd like to be remembering. Your unit must have been impecably installed and properly sized for it to still be operating.

The Rheem/Ruud modulating furnace is without a doubt the most comfortable furnace on the market. With less bells and whistles you can get a nearly comparable two stage furnace by any manufacturer. Of these, the Goodman GMS or GMV series or the Amana AMS or AMV series are the highest efficiency with the lowest price tags. The difference between the Goodman and Amana brands are the Goodman heat exchanger is aluminized steel whereas the Amana has the same heat exchanger in stainles steel. Also the Amana uses a better ignition system with a more durable ignitor.

Whatever you go with, have the contractor put in the two pipe, direct vent system. Most likely the Rheem you have is a one pipe vent using indoor air for combustion.