I have a customer who's ignitor I replaced 3 times in the last 3 years. Everything seems ok. Proper voltage, no major vibration when running, polarity ok. The only thing I noticed was a loose ground wire in a junction box near the unit. But I don't see how a loose ground wire could cause premature failure of an ignitor. Any idea's? Its a comfortmaker furnace. Thanks.
Moisture from the intake pipe when it hits the hot burner area? Is the air conditioner directly below the intake pipe? Switch the igniter to one of the aftermarket silicon nitrite replacements that they show you can hammer into wood. Bubba
When the HSI's became popular, I was told by a furnace mfg's rep that they would become a maintenance problem. I think he was right in that they are susceptible to failure from numerous sources. Vibrations(as you mentioned), late combustion, humidity, imperfections in mfg(burn outs), over stressed on installation, oils from touching element(creates hot spot on element). I used to carry almost a dozen on the van. At one point I think it was in the top 5 furnace service problems(not counting plugged filters,switching from cool to heat and changing batteries...LOL). IIRC, I think someone on the group mentioned long time back that they had stated replacing them and the relays on the furnace as a part of installation.
I agree with Bubba, retro it to one of these...
The HSI is cycling too often or staying in for too long at a time. Likely a sticking relay. Replace the circuit board or ignition module. The quality of the HSI most likely isn't the problem. BTW, and this is just my two cents, there is no justification in retrofitting the furnace in this case. It already has HSI ignition.
Sorry Richard. You're clueless. Its not actually retrofitting the furnace. It is merely replacing the silicon carbide type igniters that are horendously suseptable to breaking like glass to a tougher silicon nitrite/nitride that will last longer than a year. Bubba
Bubba, I wasn't aware of the newer version. Even so, I still recommend fixing the real problem. If the relay is sticking, then the "upgraded" HSI will also fail prematurely.
Early carbide ignitors were placed in such a way that iron flaking from the fire boxs was causing premature failure. The manufacturer's started putting the HSI's in vertically, [the thought was less chance of it being hit by iron flakes because of less exposure.]
rfofaky;
Did you inspect the fire box to see if there were any signs of premature failure or as Don said, any exposure to corrisive chemicals.?
Richard, The real problem was the silicon carbide igniters were just too too fragile and suseptible to the environments in a furnace. In short, they were not ready for "prime time". Hell the Jan-a-junks were lucky if they made it a year. Real nice though as one screw and a molex made it a less than a minute repair with a nice profit. I think they should bring them back. :-) Bubba
FWIW, I checked at the supply house for the new ignitor. They have a stack of them. Strange they never mentioned them to me. It does look tough enough to drive into a board with a hammer! I plan on stocking a few of them. I've never been happy with the universal replacement adaptors however, and those are "not" new. Also, from my own experience I'd say that around here the average lifespan of a silicon carbide ignitor is 10 to 12 years, so not really a major issue for me. Most furnaces will have the HSI replaced only once in their lifetimes.
The only problem I see replacing the stock ignitor with the Robert Shaw replacement is you will lose the AGA and UL approval for that appliance by not using the approved OEM part. As long as your liability insurance is happy with it, go for it.
Replacing one ignitor even once in 5 years [four times of the expected live of the appliance] is not a bad run at all. You do make a living performing repair sevices, no? Replaceing a motor once in the life of the equiment is expected, no? You want to keep in contact with your customers from time to time, no? You want to replace their filters what, 40 times through the live of the equipment, no? You want to replace that equiment when it's time is due, no?
Presumably they've already obtained approval as OEM replacments. They have a long list of brand and part numbers on the back of the package that the thing is supposed to replace. They even advertise it as OEM approved on the web site. It might be worth checking out, but I'll be honest, who calls the manufacturer every time they throw in a universal replacment part?
Thanks for the suggestions. FYI
The furnace is horizontal so I don't think anything is getting on top of the ignitor to cause it to fail prematurely.
I did find and repair a very loose ground wire as one of you pointed out, but I don't see how that would effect the ignitor life.
I definately never touch the ignitor to cause oil to get on it.
The unit is in a half basement/crawlspace. There is a washer and dryer on the opposite side od where the furnace is, apprx. 20ft., so I don't think it is getting effected by the detergents and such. I've seen units in tighter utilty rooms where the ignitor is older than 5 years old.
Thanks Bubba for letting me know about the slicon nitrate replacement ignitors. I never new they made one to take the place of the ceramic ones. That would probaly be the best bet to do at this point.
Presumably they've already obtained approval as OEM replacments. They have a long list of brand and part numbers on the back of the package that the thing is supposed to replace. They even advertise it as OEM approved on the web site. It might be worth checking out, but I'll be honest, who calls the manufacturer every time they throw in a universal replacment part?
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