Furnace recall accomplished?

[mimiandrews]

Can anyone tell us if the part indicated here by the pencil is the modification installed during the recall process in the 1970's and 1980's?

The furnace is an NT20A.

Thanks.

[68 TWind]

I had an NT-20 in my Trade Wind. I do know that the suspect part was a flex hose on the crossover and it looks like your is metal. I'm not going to comment if it is the correct "fix" or not, but I will tell you than you need to have the furnace checked by someone who knows what they are doing. I pulled mine, and had a friend in the HVAC business bench check the unit. I had cleaned it and it seemed to work OK. When my friend checked it, he found there was a hole internally in the heat exchanger. That could have been a deadly mistake had I used the furnace. He knew what to look for and I didn't. Moral of the story, even thought the crossover has been fixed, don't trust a 40 y/o furnace without having it thoroughly checked by someone who knows what to look for.

[jamesardis]

I believe the part in recall was similar in shape but made of rubber and usually ended up cracked--I replaced mine with a steel .

[Lumatic]

Ditto on the above. The rubber crossover tube was the problem.

[CanoeStream]

I would run, not walk, with 68 TWind's suggestion. Find someone who knows enough what they're doing to accept the responsibility for their clearing the unit as okay. Or the silly-but-wise choice -- never use the furnace.

[mimiandrews]

Thanks, guys. Now I know about the recall. Looks like the PO or the PPO had that done.

This furnace spent that forty years in the dry climate of west Texas. I found it in almost pristine condition. The PO told me he only fired it up once, and it looks like the guy before him didn't use it much either. I've had a borescope inside the heat exchanger, and it looks good in there also.

If I can get this furnace going, I'll take your advice and have an HVAC pro take a look at it. Not worth the money for that if I can't get it to light. Our plan is to use the heat strip on the Carrier we just installed most of the time. If we use the furnace, it will be in the presence of a CO detector or two. We're well aware of the hazard.

Can anyone tell me where to find those orifices that everyone says get clogged up with spider webs, etc?

[68 TWind]

That furnace does look like new. Hopefully it will check out OK.

[vswingfield]

Wow!

It doesn't look like it has even been hot once. It really does look brand new.

[mimiandrews]

Does anyone out there have a schematic for an NT20A that they'd be willing to share?

Thanks in advance.

[mimiandrews]

The furnace fired up under bench test conditions today, and it ran like it should. I ran the furnace for 15 or 20 minutes with the air output aimed straight at a CO detector, and there was no alarm.

I had to clean the pilot orifice. Thanks Andy for the suggestion of using an ultrasonic jewelry cleaner. I found that in another thread somewhere.

Also, thanks to Chuck for the furnace manual he posted in a thread back in 2005. The search function turned that up, so I had the schematics and technical information I needed.

The forums are wonderful!

[RichHog]

I scrapped mine last month and upgraded. Tried hard to get it to work but it had a dead fan motor and rusted chamber. Am attaching a copy of the service manual that was passed along to me