help needed: furnace stopped working

Today our first-floor furnace stopped working and I need some help. I think it's the [electrical] ignition that is failing but I'm not sure if I've diagnosed it properly or if I'm overlooking something...

The thermostat was 3 degrees F lower than its set point when I noticed it. The "flame icon" was on so it was trying to run the heat but there was no activity from the HVAC system. I switched the thermostat OFF then ON...I heard the vent blower (not the main blower) start up and after a couple minutes, it just shut off.

I went down to the crawl space and saw that after a long time the flame wasn't being lit. In the past, I remember the ignition system glowing reddish-orange before the gas was activated and lit (about 30 sec after the vent blower starts running), but this time I didn't see the glow. I heard a few faint clicks but that was it. No flame was lit, and the vent blower just kept running for a bit. I didn't smell any gas but then again I wasn't super-close to it, either.

I didn't see any circuit breakers or fuses related to this. Are there any?

The main blower does run when forced in the ON position on the thermostat.

The system is about 2.1 years old. We're in Southern Walk in a Dogwood. I'm not sure how long the warranty is on our particular model--does anyone know? If the unit has a parts warranty, do I need to have work done by the original installer (Wittman Mechanical)?

I'm not knowledgeable nor experienced with HVAC systems so unless it's something pretty simple that I can repair on my own, I'll call a repair place. Any recommendations?

Right now it's not an emergency because our 2nd-floor unit still runs (knock on wood). Plus it's not horribly cold right now. But of course, I'd like to get it fixed asap.

Thanks in advance for suggestions, websites, information, etc. for any of the things in my post.

 

I had the same problem I believe just a few weeks ago when we fired up the heat for the first time. Nothing would happen at all. the thermostat said that the heat was running and I could hear the furnace trying to start (going thru the long groaning) but the flame would never occur. We contacted the heating company and they came out and noticed that the ignition piece had cracked so it was not getting hot and starting the flame. They came and replaced the ignition piece. I asked them if this was common and they said yes when there is as much dirt in the air as there is in our area. Our system is just over a year old. The guy said that just one human hair on the ignition piece when it heats up is enough to crack it and then it needs to be replaced. Luckily it's pretty easy to do so. I watched them replace it. Personally I think I'm going to buy a bunch of these things so if it happens in the future I don't have to call them.

I talked to several people at work and my boss said that he has to replace his pretty much every year. He does it himself now. I had no idea these things go so often. I had the same mechanism in my previous house and had no problems for 2+ years.

 

Mine did the same a couple of months ago. I called a tech (United air temp, if I remember correctly, I am not at home, so dont have the contact info right now), he came and fixed it for about 100$ (75$ labor + parts). The problem was a bad thermocouple. The part looks like a twisted copper rod, attached somewhere close to the pilot lamp, it is attached using a hex nut I think. I have a York system, and I could tell it was a bit of a struggle for the guy to fix it, since it is not designed well enough to be replaced in a jiffy. Supposedly it is quite easy to replace on other systems. If you are the handyman type, I guess you could do it yourself. not knowing much about these systems, I had to pay a tech to come do it for me!

 

Speaking of the dirt in the air, I've got a question. We have two filters which we change regularly upstairs and I assume are associated with the upstairs furnace. But there is no filter for downstairs. I hope I'm making this clear and wanted to know is this typical?

 

You have a filter for your downstairs HVAC unit, you just haven't found it. Ours is adjacent to our basement furnace (about 1 foot from it). There is a small slit in the inlet ducting, about 18" long and 2" wide with a removable metal cover over it. The filter is in there.

Good luck with your search!

 

We have the Goodman furnace and the one downstairs is right under the main duct. There's a flap there that you have to open to get to it. Ours is I think the 16x20 filter.

 

We are in a Spruce and the downstairs furnace is adjacent to the laundry room as we do not have a basement. Any ideas on where I need to look?

The two filters for the upstairs unit take 16x20 filters.

 

I would start at your furnace, and then trace your air intake/inlet ducting outwards from there as far as you can. The filter really should be within a couple of feet of your furnace. Our downstairs furnace is in the mechanical closet in our basement (finished). We have two air intake "grates" that service the downstairs furnace: one is in the basement, the other is on the main floor. The ducting from these grates converge just prior to the furnace into an aluminum 16x24 duct, and our filter is in the "slit" in this ducting, less than a foot from our furnace. Good luck!

 

Thanks for all the help--both here on the forums and via email.

It was indeed the igniter. The part actually broken into 2 pieces.

I ended up going with Wittman Mechanical since I figured they would surely know the furnace well (since they installed it) and would very likely have parts for it readily available. Plus they were the first ones who could come out and do it.

It ended up being $124 total ($95 diagnostic + $29 labor). The part was covered under the standard warranty. It only took about 10 minutes to do the replacement (but of course, they had to show up late by an hour).

Now I know how to replace it myself so hopefully next time I'll do it myself. It's only 2 screws and a lot of care to not touch the ceramic part.

Thanks again for the help, tips, and advice!

 

Carol, did you ever find your air filter? What did it look like after having gone so long without being changed?

 

It looked like the collective sands of every place in the world she has lived have followed her home and got stuck in her filter...

 

DOH! Just noticed the dates on this thread!

SRI_N just curious, but why edit a post from 6 months ago??

Carol - Pats is correct. We also own a Spruce and the upstairs are "intake" filters so you do not have to go into the attic. The downstairs filter is found in the furnance unit since you have easy access.

And go figure. Our upstairs filters are 14x14 and 18x18. The 18x18 we have to swpecial order!