frustration!

Del

Hi!



  I was on a no heat call this afternoon.  Kenmore Hot Air Furnace(looks like it is made by Goodman), 80% with inducer motor and HSI.  Inducer starts up, pressure switch closes, 120V to ignitor but the ignitor won't light.  I replaced the old ignitor which was cracked, but still nothing.  I took the leads off the ignitor and plugged them into my lead light, and it glows right up.  I also tested both wires to the board for continuity and they checked out fine.  I also tried an alternate neutral to no avail as well as re-stripping the wires.  I was talking on the phone during the call with one of our senior techs and we sort of agreed it was the board.  Could it possibly not be sending enough amperage to the ignitor even though it is sending 120V?  Any ideas would be appreciated!



-Del

JStar

...

Sounds like a board issue. Before you replace it, I would disconnect all thermostat and humidifier wires, jump out R +W and see what happens. And check each HSI lead from the board to ground. I've had some calls where a humidifier wire was shorted out, and instead of blowing the fuse, it would prevent the gas valve from opening. Just something to think about before you buy a new board.

Bob L_3

Ignitor

I'm assuming this is not a "smartvalve", if not make sure you check every molex plug. A drop of moisture can make trouble. Your probably right with the board replacement but I would check all neutral connections again just to make sure, it's seem unlikely to have a board and HSI both fail together (not impossible though). Hope it helps a little.

Del

thanks

Yeah, I'll try that in the morning. I have a feeling it is some sort of electrical problem either in the high voltage or low. I'll go through and check if any of the wires are shorted to ground. Could it also be a problem with the furnace not being properly grounded? I noticed that one of the wires coming off a grounding screw on the fan housing was covered with electric tape.

On my way out, I found out the homeowner had been lighting the furnace with a lighter for the past week(because he asked me if I would do so...I didn't think it was a good idea), so I'm thinking the board/electrical problem happened first and maybe the ignitor cracked over the past few days. This is reminding me of the time when a helper put a sheet metal screw through the low voltage wires on a brand new furnace and I had to go through each wire and check for shorts!



-Del

JStar

Definitely

...check your furnace ground. A bad ground could cause weird static problems in the board.

Tim McElwain

Del let us back up a little

bit before we condemn an expensive board. If you have a good meter that checks amps then check to see what your amperage to the igniter is, it should be around 4.25 to 4.75 Amps if it is silicon carbide igniter (the older style) if it is a silicon nitride igniter it should be .4 to 1 amp.. Then do an RTR test (room temperature resistance) on the igniter. If it is a Norton 201 (34 second) it should be between 45 to 400 ohms. If it is a Norton 271 it should be 40 to 75 ohms. The Norton 601 (nitride) should be 50 to 300 ohms.



Next do a continuity check from the burner ground connection on the board to the gas valve, you should have continuity, if you do not then run a new wire from the board to the gas valve.

Del

bad ignitor

Thanks for all your help guys!  It turned out it was a bad ignitor, I went to the supply house and grabbed another one, and it works fine.  Before I did that I did a little low-tech test.  I hooked the leads to the ignitor to my lead light, and it lit it up.  Thanks for all the resistance info though, I'll file that away for next time. 



-Del

Tim McElwain

Del get in touch

with me at gastc@cox.net I have some manuals that may be helpful to you in the future.

don_9

hsi

Do not have anything to say thats has not been said other then, watch out for those hsi.I know of a few company that are now putting in 220 volt hsi on their gaspac.Could be you have a 220 volt ignitor instead of the 120 volt one.Just throwing it out there.

Ever see what a 120 volt ignitor does when you apply 220 volts to it?

Tim McElwain

Don, could you

give us some equipment which you have found has 220 volt igniters?

don_9

Hi Timmie

Nordyne products as in westinghouse,gibson and I believe the other name for them is nutone.I also talked with another tech in the supply store that was telling me that trane is also starting to go that route with their gas-pac.

Tim McElwain

Thanks Don, someone had

told me that Trane rooftop units had 220 VAC ingiters, I was not aware of the others. Something for me to look into.