# Igniter gets hot but pellets won't light on a Harman PF100



## ex-oil slave (Sep 16, 2010)

The igniter I have seems to be OK. Resistance is 49 ohms, 13 fins, gets hot to the touch when installed under the burnpot, but won’t ignite the pellets. Voltage going to it as measured at the main board is 118VAC by my meter. I took the igniter out and ran it off straight 120VAC out of a wall outlet. It got hotter than <that place>, glowed red hot. I reinstalled it under the burnpot and started an auto light sequence, again the igniter glowed red after about 45 seconds. Airflow seems fine. I manually lit the pellets and the air flow blowing up thru the holes in the burnpot was strong enough to make the partially burned pellets dance. Any ideas why this igniter gets hot but won’t light the pellets?  I am using new pellets this year but still had some left over from last year that were working fine. I can't get either brand to light with the igniter. The igniter burned out in the spring and I finished the heating season manually lighting the stove. I just gave it a thorough cleaning last weekend and put the new igniter in. This was my first attempt to auto light this season. I’m stumped. In manual operation (manually lighting the pellets) the furnace operates fine. HELP! IDEAS????? SUGGESTIONS????


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## SmokeyTheBear (Sep 16, 2010)

I don't know about the unit you have, however there needs to decent airflow around the igniter, sometimes this gets blocked by ash and stoves refuse to ignite.  It might also be possible that the igniter is not properly positioned and is to far away from the pellets for enough really hot air to start them up.


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## SmokeyTheBear (Sep 16, 2010)

If that unit has an air pump for the igniter that can also cause this problem if it has failed or isn't getting electricity.


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## ex-oil slave (Sep 16, 2010)

There does seem to be good airflow thru the burnpot (enough to cause the pellets to hop around when I manually light the stove and it's burning normally). I can't say whether the airflow is actually passing thru the igniter but I have to assume it is. I've had the igniter in and out a dozen times and checked the positioning. I can only see one way it will go in and it is positioned right under the burnpot floor tight up against the first row of holes the pellets reach after coming out of the auger. I've changed igniters before and never had a problem. None of this makes any sense.


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## SmokeyTheBear (Sep 16, 2010)

ex-oil slave said:
			
		

> There does seem to be good airflow thru the burnpot (enough to cause the pellets to hop around when I manually light the stove and it's burning normally). I can't say whether the airflow is actually passing thru the igniter but I have to assume it is. I've had the igniter in and out a dozen times and checked the positioning. I can only see one way it will go in and it is positioned right under the burnpot floor tight up against the first row of holes the pellets reach after coming out of the auger. I've changed igniters before and never had a problem. None of this makes any sense.



Do not assume that there is air flow around the igniter simply because there is air flow in the burn pot, for example on my stove there are two air paths on either side of the igniter plus the air path around the igniter.   It is possible that the air path around the igniter is blocked, even partial blockage can lead to ignition issues while there is plenty of air through the pot.

The igniter just heats the air so hot that when sucked by the pellets they get up past ignition temperature and light.

You might also want to make certain that the combustion fan isn't in high speed as it could be possible that too much air is preventing ignition as well.


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## ex-oil slave (Sep 16, 2010)

No air pump. Combustion motor pulls ait in under the burnpot and up thru the holes in the floor of the burnpot.


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## Delta-T (Sep 16, 2010)

did you happen to remove the ignitor cartridge from the cradle? if so its possible you put the cover plate on upside down, this could cause the problem you describe. 
jab a toothpick or something through the first few rows of holes, sometimes they just get a lil plugged up.
you may have excessive airflow through the burnpot cooling the ignitor faster than it can heat the air, you can slow down the combustion blower a bit by turning the mini-pot on the control board (located to the right of the ignitor light) counter (or anti) clockwise. 

I've never seen pellets "hop around" in a harman, this would indicate too much airflow. hopping is normal for top feed, semi-abnormal for the underfire system.


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## SmokeyTheBear (Sep 16, 2010)

According to the installation manual the PF100 does indeed have an air pump part number 3-20-02679.  Please see page 37.  

If this unit has failed or the air from it isn't getting to the igniter (disconnected or blocked air line) you'll have a hot igniter but will be unlikely to get a fire started.


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## Delta-T (Sep 16, 2010)

SmokeyTheBear said:
			
		

> According to the installation manual the PF100 does indeed have an air pump part number 3-20-02679.  Please see page 37.
> 
> If this unit has failed or the air from it isn't getting to the igniter (disconnected or blocked air line) you'll have a hot igniter but will be unlikely to get a fire started.



the compressor is only on the newer units. anything older than about 2 years will have the older style ignitor like the free standing stoves.


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## SmokeyTheBear (Sep 16, 2010)

Delta-T said:
			
		

> SmokeyTheBear said:
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Thanks for that info Delta-T.


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## wil lanfear (Sep 16, 2010)

Check the dip swithes positioning, try #1 off, #2 off, #3 on, this will provide less pellets entering the burnpot for ignition resulting in quicker ignition. The amount of pellets entering the burnpot do not need to cover the igniter for ignition.


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## vvvv (Sep 16, 2010)

moist pellets?


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## ex-oil slave (Sep 16, 2010)

Delta-T said:
			
		

> did you happen to remove the ignitor cartridge from the cradle? if so its possible you put the cover plate on upside down, this could cause the problem you describe.
> jab a toothpick or something through the first few rows of holes, sometimes they just get a lil plugged up.
> you may have excessive airflow through the burnpot cooling the ignitor faster than it can heat the air, you can slow down the combustion blower a bit by turning the mini-pot on the control board (located to the right of the ignitor light) counter (or anti) clockwise.
> 
> I've never seen pellets "hop around" in a harman, this would indicate too much airflow. hopping is normal for top feed, semi-abnormal for the underfire system.



I did remove the igniter from the cradle and I thought of that last night (the cover plate part of your quote) so I reversed the cover plate and tried again. Still no luck. Actually I was pretty excited when I thought of it as I was really looking for obscure things at that point. I'll pull the burnpot again tonight and really ream out the holes over the igniter. And as far as the dancing pellets, I'm talking about the partially burned (almost completely burned) pellets not unburned ones. The partially burned ones are very light as most of their preburned weight has been converted to heat and gases. It doesn't take much airflow to move them. But their movement does indicate that airflow is present.

Getting back to the cradle for a moment, the cover plate can be put on two ways as the holes are slightly off center. One way the cover plate lines up flush with the rest of the body of the cradle that contacts the underside of the burnpot (this is the way I think it should go). The other way it can be put on causes a bit of a lip to extend past the rest of the cradle body. This doesn't seem right but it does allow a larger area for air to flow into and thru the igniter fins. Anyway, I tried both ways and no luck.

The mini pot on the control board is already turned fully CCW but this only affects combustion blower speed in the low speed mode. When the auto light cycle first starts the combustion blower is in high speed. It doesn't shift to lower speed for a good minute or two.


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## ex-oil slave (Sep 16, 2010)

BLIMP said:
			
		

> moist pellets?



I tried two different batches of pellets. One new (sealed bags) this year and one from the tail end of last years order (again, sealed bags). I'm tearing what little hair I have left out. Arghhhhh!!


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## ex-oil slave (Sep 16, 2010)

wil said:
			
		

> Check the dip swithes positioning, try #1 off, #2 off, #3 on, this will provide less pellets entering the burnpot for ignition resulting in quicker ignition. The amount of pellets entering the burnpot do not need to cover the igniter for ignition.



I'll check that tonight. I think I already set the dip switches as you indicate. Someone suggested that fix under a thread about 6 blink codes a year or more ago. I'm pretty sure that's been done. I'll have more info after experimenting tonight. Thanking all who offered suggestions in advance.


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## jtakeman (Sep 16, 2010)

When you check the control for voltage(118V) to the ignitor, Was that under load?


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## ex-oil slave (Sep 17, 2010)

j-takeman said:
			
		

> When you check the control for voltage(118V) to the ignitor, Was that under load?



Yes, the igniter was warming up t that time.


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## smwilliamson (Sep 17, 2010)

IS it possible that you have an air leak? Is the unit pulling air from somewhere else than from through the burn pot? Is you air intake restricted? Has this igniter ever worked???


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## ex-oil slave (Sep 17, 2010)

smwilliamson said:
			
		

> IS it possible that you have an air leak? Is the unit pulling air from somewhere else than from through the burn pot? Is you air intake restricted? Has this igniter ever worked???



The igniter is new and has never actually started a fire going since I installed it last week for the first time. It does get hot (red hot) when voltage is applied.

The air intake is fine. when the stove is trying to start, the flapper on the air intake is being pulled about halfway open and if I put my hand partially over the intake, I can hear air whistling around my hand trying to get into the intake. I don't have an air leak that I'm aware of. The door gasket is in good shape. Other than the door, the firebox is sealed except for the opening for combustion air where the burnpot bolts to the side of the combustion chamber.

I've got a manometer at home, I was going to check the combustion chamber pressure (negative) this morning but was too rushed and didn't get to it. Maybe I'll go home at lunch and see what the reading is. That should be a good indication of combustion blower operation, air movement, tightness of the combustion chamber, etc.


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## vvvv (Sep 19, 2010)

flash! im thinking pellets are moving too fast thru the igniter?


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## smwilliamson (Sep 19, 2010)

BLIMP said:
			
		

> flash! im thinking pellets are moving too fast thru the igniter?


??????????


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## amick780 (Sep 19, 2010)

I had the same problem with my Harman XXV....Igniter was hot..I thought hot enough to light the pellets, but it turned out it was faulty. After playing will all the stuff being talked about here, I got a new igniter and low and behold the pellets fired right up. Give it a try, if the igniter is new your harman dealer will exchange it for a new one.


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## vvvv (Sep 20, 2010)

smwilliamson said:
			
		

> BLIMP said:
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oops wrong stove configuration? but look @ the magic! i BLIMPED the thread & seemingly actual answer appeared. hopefully


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## Dbbitt (Dec 23, 2010)

could you have installed the mounting of the ignitor upside down?


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