Furnace Ignitor Intermittently Fails To Energize

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On Friday, January 16, 2015 at 9:40:48 AM UTC-6, snipped-for-privacy@gmail.com wrote:

gnites and then blower comes on.

ostat or the door restarts the furnace, no problem. There's no pattern to i t - it'll go for a week just fine, then 2 days in a row it fails...The prob lem seems to be getting worse tho, needing more resets since I first notice d last winter.

ule not sending power to the ignitor? It's a older model Honeywell S89C1087 , no LED.

ybe I don't have one?
Here's what you're looking for: http://i1181.photobucket.com/albums/x430/Be nDarrenBach/thidHN_zps366700fe.jpg If any attached tubing gets water in the m, it can cause an intermittent or lock-out problem. Condensate needs to dr ain efficiently.
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snipped-for-privacy@gmail.com wrote:

It could be. If you have owner's manual or schematics you'll see it there. I am only familiar with Carrier products having them in my house always. But basic idea is same. Can't find a small tubing around the inducer chamber(motor)? Ignitor is just goo dor bad and it is controlled by a relay(some times solid state type) on the control board.
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You may have a spark gap igniter:
(Amazon.com product link shortened)
....that is beginning to fail.
I've replaced 2 igniters in 7 yrs. I now keep a spare next to the heater. Usually, they fail completely and totally, but you may have a different type. There are 2-prong and 3-prong versions and they're cheap (< $20). Mine is 3 pronged and has a connector at the igniter so I need not replace the entire wiring harness, jes the igniter. These are pretty old technology (house current?), so are fairly simple.
nb
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Thanks nb,
i just installed a brand new Nordyne ignitor, yesterday. The old one looked a little aged so i also thought that would solve it - but this morning still same problem.
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On Friday, January 16, 2015 at 2:29:19 PM UTC-5, snipped-for-privacy@gmail.com wrote:

still same problem.
You need to troubleshoot the steps that happen before the ignitor is turned on. I think the logic is that the controller starts the inducer motor but it wi ll not start the ignitor until the pressure sensor is happy. So if the pre ssure senor is not happy, the inducer motor is not getting the correct air flow in the flue even though you hear it running. The flue may be clogged or the pressure sensor is bad or ?
Mark
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Funny this thread came up. My central forced heater jes failed. The heater had been running for 20 mins and the room temp kept dropping. I had half a tank of propane (250 gal) and the oven worked fine. Must be that danged spark gap igniter.
It was not the spark gap igniter being literally burnt off at the stubb, like I've seen before. The problem was "whiskers" forming on the igniter tips and shorting the two electrodes out, intermittently. I pulled the igniter (4 screws) and cleaned the "whiskers" off and put it back together. It works, now, but I suspect those whiskers will continue to rapidly form on the now corroded electrode tips. Probably will until I put in that new igniter.
BTW, my 3 'trode igniter cost $39, not the "less than" $20 I quoted before.
nb
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Hi Mark,
I don't believe there is a pressure sensor in this model. There's no mention of one in the manual or the parts list, and I don't see one visually.
What it does have are a few relays, that supposed to tell the other components to turn on... I'm now thinking that one if these relays are faulty, and maybe the S89 cntrl module isn't getting power ... the relay is a cheap part, $15 bucks online.
i'm thinking now - when it fails to use a voltometer on the s89 to see if it gets any power at all.
Am I on the right track here ?
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It all depends on the motor. I just replaced a similar part on my well pump motor. It is a set of contacts that puts a capacitor in line with the motor to start it. Just a couple of screws and push on terminals.
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I was able to get the cover off the motor, exposing the centrifugal switch. ..it looks brand new and clean inside - I blew some canned air into it, cle aned the contacts, put a few drops of oil on the shaft, then closed it up and oiled the front end through the oil holes. Motor is quieter but still the same problem!
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On Tuesday, January 20, 2015 at 6:36:15 AM UTC-6, snipped-for-privacy@gmail.com wrote:

leaned the contacts, put a few drops of oil on the shaft, then closed it u p and oiled the front end through the oil holes. Motor is quieter but stil l the same problem!
If this is a 2-wire (W/Grnd) motor, then it's just for a start winding.
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On 1/20/2015 7:36 AM, snipped-for-privacy@gmail.com wrote:

brand new and clean inside - I blew some canned air into it, cleaned the contacts, put a few drops of oil on the shaft, then closed it up and oiled the front end through the oil holes. Motor is quieter but still the same problem!

You now have one more repair that is known to NOT fix your furnace.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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On Friday, January 16, 2015 at 7:06:43 AM UTC-5, snipped-for-privacy@gmail.com wrote:

es and then blower comes on.

t or the door restarts the furnace, no problem. There's no pattern to it - it'll go for a week just fine, then 2 days in a row it fails...The problem seems to be getting worse tho, needing more resets since I first noticed la st winter.

not sending power to the ignitor? It's a older model Honeywell S89C1087, no LED.

SOLVED !!!
Just an update: I limped through last year, didn't want to start messing ar ound with it too much when the temp was -25. This fall replaced the Igniti on Control Module s8910u1000, 75 bucks at Amazon and an hour of time.... Ss o far so good, has always come on!
Thanks for all the feedback!
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