Help Please, Furnace won't turn on

lh0628

hello everybody. I'm very new to the forum, and I'm here for help.

I have a Carrier natural gas furnace that won't turn on. Please allow me to describe how it normally works.

1. fan comes on for xx seconds
2. a metal stick thing (sorry not sure what it's called, but it's located right in front of where the gas comes in) turns yellow/orange
3. gas comes in, flames come up
4. Heat!

Problem:

the metal stick thing (sorry again about my lack of knowledge) won't turn yellow/orange.

I would guess I have some faulty/dirty parts that's not working properly. Could you tell me what this is? Is it model dependent? The furnace has a few labels on it but I don't see one that looks like a model number.

Should I just be able to take the part to a hardware store, get a new one and put it back on?

p.s. Is it safe to try to light the gas myself with a lighter/match when the gas comes on? I've seen people doing it to test if the furnace is working properly, but it does seem a little

Thank you for reading about my problem, any help and suggestions are appreciated.

Thank you.

lh0628

I did some digging and took a couple of things off.

One is the thing that looks like that have ceramic coating on, it sits right in the middle of the two gas valces, a bit to the left, and it's connected to 2 white wires. I inspected the ceramic part, the middle part looks white (prob from heating up?) and also it seems to have a crack on one of the four stripes/twigs.

Another thing I took out looks almost like a hex tool, it's connected to a pink connector, sits right in front of the right gas valve. It also does look dirty.

I cleaned both with 400 grit sand paper, nothing to drastic. Put them back in. Now I forgot at which angle did the second thing sat in front of the gas valve. Does it matter where it sit?

Again thank you for your help.

lh0628

I think the 1st thing I was talking about is called "hot surface ignitor"

It's the thing that normally glows, but right now after I turn the furnace on the blower fan comes on -> I hear a click -> I smell and hear gas gets released -> this repeats 3 times and then the furnace just stops (blower fan stays on though)

scorrpio

You gotta provide model number of your furnace in order for anyone here to be of any help.

But yes, looksl ike your ignitor is busted.

On a hunch: Is THIS it? If there is a crack anywhere along the ignitor, you need to order a new one.

scorrpio

And if the other part you are talking about looks like THIS, that's your flame sensor - you gotta put it back so its tip is in the flame when burner is on.

lh0628

That is EXACTLY what it looks like, thank you! It does look like there's a small crack on it and I did touch it by hand and I sanded it

The other part I took off looks like THIS. I sanded this too and it looks ok. BUT when I put it back on I forgot at which angle it sat in front of the gas valve, I suppose it does matter how it sits? Would I just have to adjust the angle until the furnace works?

Thank you again for your help!

lh0628

I was typing a reply while you wrote this

Got it, as long as the end is in the flame it's fine then

lh0628

Turned out it was the hot surface ignitor, went and got one, installed everything back, now I have heat!

Very expensive though $75 compared to the link you provided... oh well can't wait for shipping.

Thank you for your help scorrpio!

scorrpio

You are welcome. $75 sounds a bit steep indeed, but glad your problem is fixed.