American Standard Freedom 90

Tinkerer · 11-13-2008, 05:17 PM

Hello all, I have an 11 year old house with the aforementioned furnace installed. I have had it serviced twice a year since we bought the place and not had any major problems. This past week, my service man showed me the rust in the heat box and on the venturis and said that we will have a CO problem if it rusts through and he told me that the life expectancy of the furnace is 12-15 years. He said I'm looking at replacing the entire system in the next year or two. Can anyone tell me if that information is accurate? If I have to replace it, should I be looking at a complete system (heat & AC) and lastly, since everything is already installed here, is it advisable for me to purchase the system and put it in place and have a pro check it, set it up and verify operation? With the current economy, I really can't see spending $10k to have a new system installed if I can save some cash by doing it myself. Thanks

pipefitter636 · 11-13-2008, 05:54 PM

What is the model and serial number of the furnace? LP or nat gas?

Tinkerer · 11-13-2008, 08:32 PM

Quote:

Originally Posted by pipefitter636

What is the model and serial number of the furnace? LP or nat gas?

It's Model # AUC080C942B3, Serial # M134KM57Gi and it's LP. Sorry to be ignorant, but wouldn't a stainless box be better than galvanized?

kennzz05 · 11-13-2008, 08:42 PM

Quote:

Originally Posted by Tinkerer

It's Model # AUC080C942B3, Serial # M134KM57Gi and it's LP. Sorry to be ignorant, but wouldn't a stainless box be better than galvanized?

its not unheard of but theres more than likely something in the installation that caused the failure like its not terminated properly and is sucking in the discharged condensation or is underfired and isnt getting warm enough to remove the condensation perhaps tinkerer can provide more info for your specfic unit

Tinkerer · 11-13-2008, 08:57 PM

The service guy told me that since LP has a higher moisture content, that this will happen over time. I'm pretty handy but don't have the background to know whether he's pulling my leg. The cycle time doesn't seem off to me, i.e., it doesn't fire up and run for a minute then shut down. There is a bypass himidifier installed but that wouldn't affect the venturis getting rust???
Could it be the length of the exhaust pipe? The builder had the exhaust run about 22' with 4 90's and 2 45's. I'm assuming he ran it that far to keep it from discharging directly under a window, but I'm sure I could set up a shorter run to the same exit point.

kennzz05 · 11-13-2008, 09:11 PM

you need to call trane or see if the install manual is available and see if thats ok with there unit sounds ok but all units are differant. with propane the furnace has to be coverted to lp as it comes shipped for nat gas the conversion isnt a big deal a spring in the gas valve and differant orifices i doubt it could run all this time without being converted but i suppose its possible call trane tech support ask them what orifices should be in your furnace (it will be a number) like#55 for example to find out what orifice size you have now pull one burner(shut gas cock first) and the orifice is located at the base of the manifold where gas shoots into the burner you might be able to take a mirror and read the number stamped on the face if not take a 1\2? wrench and unscrew it i really dont remember the size wrench tho..... good luck

am standard and trane are the same

Tinkerer · 11-13-2008, 09:27 PM

Thanks, I'll see if I can take a look at it this weekend. Are the heat exchanger & burner venturis replaceable or not worth doing?

If I replace the system, I was thinking of going with a 2 or 3 stage unit but your comment about being underfired makes me wonder if the savings I have on fuel would justify the shorter life of the exchanger or is that not an issue?

kennzz05 · 11-13-2008, 09:36 PM

Quote:

Originally Posted by Tinkerer

Thanks, I'll see if I can take a look at it this weekend. Are the heat exchanger & burner venturis replaceable or not worth doing?

If I replace the system, I was thinking of going with a 2 or 3 stage unit but your comment about being underfired makes me wonder if the savings I have on fuel would justify the shorter life of the exchanger or is that not an issue?

im glad you brought that up i forgot to mentionin all probability that heat exchanger is got a lifetime or at the minimum a 20 year wAARRANTY call trane again, they can fill you in on all the details, it is replaceable and not all that bad everything in the front has to come off than the xchanger comes out the front ask trane for a copy of the install guide to see if all is well with the install

i just reread your post your only allowed 4 90s on the exaust where does intake come from is itside your house or attic/crawlspace unconditioned?

Tinkerer · 11-13-2008, 10:28 PM

Thanks for that info, I'll definitely call Trane about the warranty. The unit is in the basement. If it only allows 4 90's, then the builder put in one too many with the 2 45's added in there.

kennzz05 · 11-13-2008, 10:34 PM

Quote:

Originally Posted by Tinkerer

Thanks for that info, I'll definitely call Trane about the warranty. The unit is in the basement. If it only allows 4 90's, then the builder put in one too many with the 2 45's added in there.

guess it didnt get inspected huh? (no permit) with 5-90s let me know what happens