Based on posts on this forum (thank you!) I believe I have a hot surface ignitor issue, but I can't find the hot surface ignitor.

My furnace model is 350mav048100 (specifically 350mav048100ADKA). According to the manual, the Bryan 350MAVs have a hot surface ignitor, but I can't see it.

I've included a couple of pictures that probably aren't helpful. Does anyone have any tips?

Thank you kindly in advance!

 

I’m unsure if the issue is related to your problem or not, but that furnace is involved in a class action lawsuit for faulty heat exchangers.

http://hipspro.com/pubs/Furnace-clas...led_notice.pdf

There is a hot surface igniter, it’s the white plug in the back.

 

And here's a video showing the burner area as well as I can -- there's just no obvious HSI.

 

Thank you roughneck.

 

What issue is the furnace having? What problem are you looking to solve?
I strongly suggest getting the furnace tested to see if the secondary is compromised. All these furnaces will have issues.
When they start to fail they have a high elevation of carbon monoxide in the exhaust. As the issue progresses they develop an unpleasant odor out of the exhaust that will sting your eyes and throat.

 

I added and labeled your last picture.
The yellow arrow is the supply half of the igniter plug.
The green arrow is the igniter side of the plug.

 

@PJmax - thank you! For anyone looking in the future, here's a couple of videos that shows exactly where the HSI is: https://www.youtube.com/shorts/fiTlo...?feature=share

In my case, i was able to lift the black pipe out easily -- just raising it enough to remove the nut holding the HSI in place. Then use any screwdriver to push the latch back (the one that holds the HSI in place), and pull out. Looks damaged I believe.

damaged HSI I think

 

roughneck -- thanks!

>>>What issue is the furnace having? What problem are you looking to solve?
It's not firing up -- so, no flames. Otherwise the ignition sequence "seems" fine to me, not that I know much.


>>>>I strongly suggest getting the furnace tested to see if the secondary is compromised. All these furnaces will have issues. When they start to fail they have a high elevation of carbon monoxide in the exhaust. As the issue progresses they develop an unpleasant odor out of the exhaust that will sting your eyes and throat.

Thank you. If you think my situation is in fact likely to be the HSI, given it looks damaged, I assume you would still do this as a generally good idea. We haven't had any issues with this unit in, well, about the 7 years we've lived here. But it might be ending its life soon. What would indicate to me that the secondary is compromised or that the unit is starting to fail?

Regarding carbon monoxide -- scary! I appreciate your warnings here and on other posts. Maybe I'll get a CO monitor and put it in the basement near the unit. I'm not exactly sure where the exhaust is -- is that the same as the steam vent on the outside of the house?

 

I’m not sure what you mean by steam vent. Condensing furnaces can put vapor condensation out of the exhaust.
What step in the ignition process is the unit failing at? Is the igniter getting power when it should? Is it glowing if the igniter is getting power? Is the gas valve getting power? Failing to ignite is one of the symptoms of a failing secondary, it disrupts the draft through the heat exchanger.
Yours appears cracked.
When the secondary starts to fail the first signs are elevated burner box temperatures. These can start to be accompanied by random rollout trips. These conditions will worsen to a terrible obnoxious odor by the exhaust and constant trips on rollout and limit.
Don’t by UL listed carbon monoxide detectors. They aren’t programmed to go off until 75 PPM or above has been archived for at least 4 consecutive hours. You’ll want low level detectors.

 

>>>What step in the ignition process is the unit failing at? Is the igniter getting power when it should? Is it glowing if the igniter is getting power?

The igniter is not getting power -- it looks damaged to me and based on reading other posts on this site showing pictures of damaged igniters -- what do you think?

 

If you say it’s not getting power, you would have done this with a meter, then the igniter isn’t the problem.

 

The igniter in your pictures is definitely cracked. You said it wasn’t getting power though, so if that’s true that it’s not getting power then a replacement igniter would not work either. My guess is that you didn’t check to see if it’s getting power and just noticed that it wasn’t glowing anymore. If thats correct then replace the igniter (robertshaw 41-409 should be a direct replacement). Don’t touch the silicone carbide part of the new igniter with your bare hands as the oils on your hands can damage the igniter. Most importantly though, As roughneck mentioned your furnace is part of a class action lawsuit and needs to be checked out by a competent service tech who has and knows how to use a combustion analyzer to make sure it’s still safe to use. I’ve seen so many of those heat exchangers fail when they fail they will overheat and melt and char the combustion air inlet pipe, produce well over 1000 ppm of CO, and are very unsafe.