UPDATE: Local HVAC contractor had a new Fasco equivalent for the old p/n inducer assembly, which had been on their shelf since 2014. Gave me a 1-year warranty and cash/carry price of $250 plus tax. I switched it out, and we’re up and running toasty again. Thanks for the help guys!



Armstrong Ultra SX 90 natural gas furnace, serial no. S8499G31090. The inducer fan motor (gas purge fan) doesn’t want to run. It’s getting current, so I shut off the power to the unit, and the electric motor was slightly warm to the touch from trying to run. I took the inducer assembly out, and the squirrel cage fan spins, but I can hear a bearing squeaking a bit.

I let it cool down, re-installed, and it went thru all the normal startup sequence; purge cycle, igniter glowed up, gas valve, fired, blower motor etc., but only for about 60 seconds. Then the inducer motor quit (electric motor wasn’t warm at all), so once the inducer shut off, the gas valve shut off, blower continued to run for cool down cycle, then everything shut off. When I cycle the power switch off/on for the furnace after that, I can hear the inducer motor loading up (so it’s getting current), but it won’t run. At least until it fully cools down.

I should mention that there was a little moisture inside the inducer squirrel cage, and also evidence of a little moisture below where that would drip off inside the furnace housing body. Not gobs of water flooding it, but clearly some condensation or something building up.

Any other ideas what to check?

Would I be foolish to buy a new inducer assembly ($200-$300??) for this thing, and hope that’s all it is? Even if I can get one for a 25 y/o furnace. How much would a new equivalent furnace cost, installed? No central air, just heat. House is older 2-story, 2k sqft appx., in rural Wisconsin.

Thanks for any ideas/help!!

This message has been edited. Last edited by: Outnumbered,

25 years is a good run for a furnace. I know spending a lot of money is not ideal to replace but I think that is probably what you are looking at. I would get three bids to replace. I would expect one to be a covid bid. Very high. But you should be able to get a reasonable bid to do a change out. There are many good, not best furnaces on the market that will do the job very well. Best of luck.

I had an HVAC issue a few years back. The co came for evaluation. Part was repairable, then had to get some new.

Like an older vehicle, sometimes better to put some repair $$ in, other times it’s throwing good after bad. I’d start with an evaluation from someone well versed.

I have a 28 year old carrier furnace that I replaced the inducer motor on over 3 years ago and it is still running. The worst thing to happen to a forced air furnace is that heat exchanger rusts out and goes bad. If you know somebody with a combustion gas analyzer you can get a read out on your furnace. Or try to find a reputable HVAC repair guy. I work in the commercial HVAC side (but in a college campus setting) and I just see a lot of people buying new units when they don't have too due to agressive HVAC service companies.

quote:

I just see a lot of people buying new units when they don't have too due to agressive HVAC service companies.

Absolutely, these same companies quote high repair costs and many times the guy coming to analyze the situation is trained to do just that.

Hear two of them outside talking about "watch and see how I sell them a $10,000 new install" I let him run the pitch and tossed them out.

Found a nice family run independent company who came out and replaced a part and it's still running fine three years later.

Go on FB marketplace, look for a repair person/company, check reviews, ask question and then have one come out to see if it's fixable.

Or stick the $200 - $300 part in yourself and see if it works, save the call fee.

Just to be clear. I am not saying that your furnace cant be repaired. Maybe it can and would be worth doing. But I also think a replacement is not out of the question. You get a piece of mind of a new unit with a warranty. And I am not thinking every hvac person is out to screw you over either. Like everything else. There are good and bad. Good luck.

Rugged cross makes really good points. It is no
different than having an older car--do I get a new one or keep dumping money into the old one?

Maybe ask around your neighborhood and find a reputable HVAC company? Here in Wisconsin it is going to be -2 degrees tonight and no furnace is a really big deal.

Dec 3 in rural Wisconsin?

I'd get it fixed pronto (providing it's just the motor replacement/repair) and then decide/shop for a new unit in spring.

I'm not an HVAC guy - but based on what you're saying I'd be tempted to order a new fan and give that a go first, assuming you can get the part fairly quickly.


I replaced my inducer fan motor a couple years ago (my furnace is 22 years old). It was pretty simple to replace. I recall running some space heaters during the day and doing a lot of baking - that kept my house warm enough until the fan got delivered.

Lots of suggestions for busting out the parts cannon!

Outnumbered,
As a suggestion, if your furnace has a Flame Sensor that sticks down into the combustion area and into the flame, it may be contaminated and not sending the correct signal to the computer. Your symptoms sound like the ones I experienced when my flame sensor was contaminated.
To clean it, I remove 1 screw, and gently pull it out of the combustion area. I use steel wool and some relatively fine sand paper. Just a couple of times back and forth along the length of the sensor is all that is needed to clean the crud off of it. Reinstall and see if your furnace will operate normally.

You're already about 5-10 years past the useful life of that thing.

Replacement is an inevitability.

Call a pro either way.

If you are able to get it running again for a few hundred $’s or so, are you willing to roll the dice and have it crap out again during the worst winter storm of the year?

A new unit will be under warranty, parts will likely be available, and the reputable and reliable HVAC company that you choose to purchase and install your unit from will hopefully respond quickly.

Look at Amana for their good products and excellent warranty.

One minor but not insignificant benefit if you decide to replace it is that newer furnaces are much more efficient and you can get up to 96% efficiency where yours is probably around 80%.

quote:

Originally posted by Outnumbered:
UPDATE: Local HVAC contractor had a new Fasco equivalent for the old p/n inducer assembly, which had been on their shelf since 2014. Gave me a 1-year warranty and cash/carry price of $250 plus tax. I switched it out, and we’re up and running toasty again. Thanks for the help guys!
...

Glad to hear your back in the comfort zone.

Had an issue with my unit last year with hard starting and trying to troubleshoot (disassembly of the entire furnace/air handler) with below freezing temps, for a week. No fun in that.

Never heard a cat's teeth chattering before...

Nice, win, win!

Great job!! I’d really not care to be rushed into new on short notice.

Nice job - that's great!

Mine is 22 years old and it's on my radar for replacement at some point. The one I have has a 92.1 AFUE rating which is pretty efficient so there's minimal month to month cost savings to upgrade from that perspective.
I'll run it as long as it's safe and inexpensive to fix.