skippy

We may have to get a new furnace. Can anyone recommend a good, long lasting natural gas furnace? We would want one with a good reputation for being reliable and low repair rate.

What efficiency rating should it have? 80% 90%

What about flue venting, should it be a chimney liner or side wall venting. Sidewall venting would be better in the long run since it would not corrode out like some chimney liners?

Any suggestions welcome.

skippy

mdshunk

Get a high efficiency plus 90 furnace (92-93% or so), and you won't have to worry about venting it. They extract so much heat out of the combustion process, that the vent gasses are quite cool by comparison. They are designed to vent through a piece of ordinary PVC pipe.

Brand? Eh, you certainly get what you pay for. I answer HVAC questions on a couple of other boards, and I seem to get an overwhelming amount of Armstrong trouble questions. That might be deceiving. Either that brand has troubles, or there's just simply a hell of a lot of that brand installed.

My personal favorite is Trane/American Standard for high end, with Goodman/Janitrol for the mid grade.

ContractorSon

You like Janitrol/Goodman? What about Rheem?

mdshunk

I think it is more important to focus on shopping for a good installing contractor, and worry less about the brand. Find a good contractor, and he'll put in good stuff.

K2

I had 4 ducane's put in 8 years ago and have been real happy with them. They have a lifetime warranty on the heat exchanger and our local boys have a zero tolerance policy for cracked heat exchangers. (even one very tiny crack). I've heard that 80%'s are less maintenance but that may have changed in the last few years. I don't know if they make furnaces with standing pilots anymore but I keep a stock of ignitors and make sure i know how to change them. Not that they go out very often but when they go out on Christmas morning it is a drag and very expensive. I've got some standing pilots on some new boilers and they seem bullet proof.

skippy

Thanks for your input. This will be the first furnace we bought if we get one. Our old one is 17 years old and not efficient. MDSHUNK tells about the pvc but I have read somewhere about the pvc pipe sweating which causes drips to fall off it. Also what if you had a furnace with sidewall venting then in 16 years you need another furnace, are you left with a gaping hole in your wall or will the replacement furance utilize this same hole in the wall?
ROB53 about the heat exchanger. We had a friend whose furnace had a 20 year heat exchanger warranty. Well after about 14 years it developed a bad crack. They called a repair person and were told that it would cost quite a bit for them to tear down and replace the heat exchanger. Even though the heat exchanger was free under warranty labor was not and they'd be spending alot of money in labor. Might be better to get a new furnace. We noticed many companies have extended heat exchanger warranties but is it any good since its so costly and so much work to replace it?

K2

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That is a good question. Ducane had a five year parts and labor warranty too and took care of a few problems no charge but i think you might be right on the heat exchanger warranty. I'll have to hunt up my paperwork.

HVAC Doc

I have only seen sweating PVC vent pipes on high efficiency furnaces on ones that were imporperly installed either without the proper slope as the manufacture recommends or the unit is oversized. If you get a high efficiency furnace and ever do need to change it out, you would have to go with another high efficiency furnace. But then again, if the DOE steps up on furnaces as they have with a/c and heat pumps for January 2006, it may be a non-issue in 10 years. As for the cost of replacing a heat exchanger, it is true that unless you have a parts AND labor warranty, the cost of labor is not covered under repairs. Labor is most generally only covered under the first year of a manufactures standard warranty. That even goes for the units with lifetime compressor and heat exchanger warrantys that offer a whole new furnace or a/c (not just the part that failed). In most cases (not all, there are always exceptions) the labor to change a heat exchanger shouldn't exceed 1/3 the cost of a furnace. Now if it is in a small crawlspace or up in an attic, or suspended above a false ceiling or on a rooftop then yes, you could expect some additional labor.

skippy

Well we had a contractor recommended to us and they were out today. We are getting an American Standard Freedom 90 Comfort-R furnace. It will have
sidewall venting. All of your replies have been most helpful and are appreciated! Thanks to all.