Gas ignitor only lasts one heating system

dpeart

I've a gas furnace and about 4 years ago the ignitor went out. I had it replaced and it worked fine for the rest of the heating season.  When the next season came along, it was broken again and had to be replaced.  I then had the entire furnace serviced, where they removed everything acid washed the coils, updated all connections to meet code, and checked/serviced all the controls and installed a new ignitor.  It worked great for that season, then on the next season was broken.



What else can I have looked at?  It seems silly to pay $75-$100 every season to just get a new ignitor installed.  Can I remove it after the heating season is over, and then re-install it later?  Seems weird to have to do this, but it would be cheaper than getting a new one installed each year.



Ideas?



thanks

dave

unclejohn

Make

And model would be helpful.

Jean-David Beyer

What else can I have looked at?

I am responsible for two 125,000 BTU/hour forced hot air furnaces. They were installed by what was (formerly) a good contractor. Time passed and they became more successful and started buying up some of the competition. Then ignitors started failing during each service call. After a few seasons of this, we replaced contractors, and we have not replaced ignitors in over 3 years.

heatpro02920

C'mon it couldn't be the contractor...

That's a little harsh, lol... While I have seen worse, I like to think that most contractors are honest and if they wanted your money they would say something else failed the next year. So year one the HSI year two the flame sensor, year three the inducer motor, ect BUT buy this time I would hope the property owner would say "why is my unit breaking everytime you are here?"



As I read the post, I think it is breaking when they are not present? we need a little more info, make model, of unit and parts being changed...

Tim McElwain

Is it a furnace or

a boiler there is a difference. What is the make and model as that will help in case there is a particular history. By the way some contractors change the igniter every year because some trainers tell them that is what to do as it will prevent a service call during the heating season.

Jean-David Beyer

That's a little harsh,

I did not mean to imply that they were deliberately breaking the ignitors, just that they did not realize how fragile they were once they had been used for a year. And that was only the least of the reasons for switching contractors.



It was just as the contractor's business expanded, they could not (or did not) increase the number of qualified technicians and they could not manage their business as well as when they were smaller.. When I, as a homeowner, find out that I know more than the contractor, it is time to find a better contractor.



I have no idea if the original poster here has a contractor problem. But he might take it up with the boss of the contracting outfit. I did not mean to imply that it was being done deliberately.

dpeart

It's a furnace

I'll get the make and model and post it.



dave

Tim McElwain

Is your furnace getting its

air for combustion from outside or from the room in which it is located? Igniters tend to last longer when air comes from outdoors, the indoor airborne VOC's (Volatile Organic Compounds) tend to drastically shorten the life of the igniter. That along with high voltages, short cycling etc.



Igniters both silicon carbide and silicon nitride have a somewhat short life as compared to other ignition systems.

dpeart

It's a Goodman

The combustion air comes from insides.  The furnace worked great for many years, now I get one season out of the ignitor.  The ignitor works when we go to AC, but when we go back to heating it is broken.  I'm wondering if vibration or something can break them?

Goodman

Model # CACF036A2A



thanks,

dave

Tim McElwain

You do not use the

igniter when you are using the AC so it has no effect. When they change the igniter what do they say is wrong with it? Is it broken as they are very fragile? They should give some explanation as to what the problem with the igniters could be such as cracks, bright spots, high resistance etc. What do they get when they test the amperage with the igniter?

dpeart

Cracked

The one they showed me had a crack/fracture at the tip.  I don't know if they have checked the amperage.  That is something that I can ask. 



dave

Tim McElwain

Is this a silicon carbide or

silicon nitride ignter?



The Norton 201 and 271 silicon carbide igniters have now been replaced by a nitride igniter which is much more durable. The resistance of those igniters at room temperature should be for the 201 45 to 400 ohms, for the 271 40 - 75 Ohms. They should be operating between 4.25 to 4.75 amps when powered.



Make sure the flame is properly adjusted and that the burners light smoothly a heavy ignition  can cause the igniters to crack.



Was a combustion test run on this unit with an electronic analyzer?