Question on hot surface ignitors

[dec]

Had a call tonight on a gmpo75-3 Goodman.Homeowners claimed there furnace had a bad blower motor and needed it replaced but didnt know what brand it was .Went out an looked at it and it had a burnt hot surface ignitor. I didnt have the right one with me so I stuck on one of my 41-408 uniline that I use for a lot of rheems. I know its not the one I really need but I wanted to get them some heat being its a weekend and it is pretty close physically so I put it on to see if it could get me by till monday when I can get the right one. I did notice that a few times that it didnt light the burners on the first attempt of the ignitor but it would light after a few atempts. I guess my main question is their that much differance in all of the ignitors that you cant use some of them in differant applications? And if that most likely why it didnt light the first time everytime. I will test my gas pressures once I put the right one on. If that is so does everyone carry a huge assortment of them? After I got back tonight I looked to see if I could find the ignitor # I need, looks like a L38-046. I also see a L39-089 for Goodman too but thats not the one. What I have to carry all of them lol.

[dave82323]

alot of times the wrong hsi will do the job.. In the future install what you have in an emergency and inform the homeowner that you will have to come back.. collect payment or you will possibly loose out... good luck

[dec]

I guess Im still hoping for a few responses as to whether the burners not lighting on the first ignition of the ignitor is probably more likely the cause of it not being the exact replacement ignitor or something else such as gas pressure or something else . Just wondering if its something common on the Goodmans. Hav'nt really run into this being I have pretty much had the right ignitor with me and if I replaced it they always worked with out having to try more then one time to light burners. Any goodman dealers see this as common, ignitors failing because of problem with ignitor not lighting on first attemps so they wear out prematurly?

[Jax]

Goodman only has two Hot Surface Ignitions. The GMP and the GMS.
The GMP has a fixed duration while the GMS is self adjusting for shorter cycles.

I don’t know why the burner would not fire if the HSI was hot, and in the burner path when valve engaged. Sounds like there may be other problems. It certainly is not common for it to NOT light on the first try. Something is wrong! Is the length and size the same?
Jax

[davyc]

Other than obvious physical differences the other difference is the warm up time of the ignitor. The Ignitor reaches temperatures of 2500 to 3000 degrees in a fairly specific time frame. The norton 201 igniter takes approximately 20 seconds to reach 2500 degrees and is used in controls having a 34 second warm-up period. The norton 271 igniter has a faster warm up time of 17 seconds. I have a couple of universal ignitors on order that I am going to try out to keep from stocking several different varieties on my truck or having to run to the parts house only to find they are out of stock. I myself am still in the process of finding out new information about them an their differences.

[turtleninny]

A while back I had a york furnace with a burned out hsi. It was one of those coiled type around a ceramic insulator (like you see in clothes dryers). The parts place informed me that that ignitor was no longer made and handed me a universal hsi (already had 3 on my truck) Anyway -- I had to build a bracket out of sheet metal to position it where the old one sat , but darn if it didn't work just fine.

[Edited by turtleninny on 02-06-2005 at 01:21 PM]

[gje1]

You would think if the positioning or the length was wrong you wouldn't get ignition the seconded time.

[Edited by gje1 on 02-07-2005 at 12:57 PM]

[dec]

Originally posted by Jax
Goodman only has two Hot Surface Ignitions. The GMP and the GMS.
The GMP has a fixed duration while the GMS is self adjusting for shorter cycles.

I don’t know why the burner would not fire if the HSI was hot, and in the burner path when valve engaged. Sounds like there may be other problems. It certainly is not common for it to NOT light on the first try. Something is wrong! Is the length and size the same?
Jax

yes it is exactly the same other then the little guide piece on the porcelain where it holds it in place on the mounting braket, it was a little longer so I rework that. Would have thought it would make no differance being the ignition board would tell how long to put power to ignitor to let it light. Its almost like its not rectifying back to open the gas valve, maybe a bad conection in the molexes?

[trane]

My first guess would be the distance between the crossover and the ingniter might be more than it should be. We have had problems with this on the York spiral ignitors when replacing them with Norton mini ignitors that replaced them. Second would be gas pressure.

[karsthuntr]

Your timings are differant.

The goodman has a 17 second warm-up time and the Rheem replacement you used has a 34 second warm-up time.

It lights on the second try because ignitor is warm from previous ignition.

[dec]

Originally posted by karsthuntr
Your timings are differant.

The goodman has a 17 second warm-up time and the Rheem replacement you used has a 34 second warm-up time.

It lights on the second try because ignitor is warm from previous ignition.

Many thanks karshhuntr That was the answer I was looking for. I had a feeling that that ignitor may be the problem and Im glad I didnt mess with the gas pressures before trying the right one. thanks again for sharing your knowledge.

[dec]

Originally posted by karsthuntr
Your timings are differant.

The goodman has a 17 second warm-up time and the Rheem replacement you used has a 34 second warm-up time.

It lights on the second try because ignitor is warm from previous ignition.

Karsthuntr I have another question for you then being your pretty knowledgable about this. If you were to use a goodman ignitor ifits a 17 second warm up time on a rheem ,would there be a problem of it wearing out prematurely being the heat would be on it for 34 seconds? Any problems you could think of in that wrong configeration of heat on the ignitor? Also if you do know just for my always wanting to know the reasoning, what do they do differantly to the ignitors to change the amount of heat needed to be on them? Is it something to do with they make the material for each differant ignitor or what? just makes me curious.

[karsthuntr]

I'm not sure about this but it seems that if you put a 17sec ignitor on a Rheem it would burn-out much quicker.

It would have to be made in a differnt way beacuse voltage is the same for both ignitors.