Harmon PB 105 trouble with ignition

[BRADLEY]

Need to determine the quanity of pellets in the burnpot prior to ignition. First, shut down the boiler, clean out the burnpot of all pellets, close it back up, power the boiler on, as soon as it stops feeding pellets, prior to a lot of smoke, open the firebox door, power down the boiler, swing open the pellet storage bin so you can see the quanity of pellets in the burnpot. If the quanity of pellets in the burnpot is completely covering the area where the igniter is located, to many pellets are being fed at startup. Ideally, the pellet level should be just so they are starting to cover the igniter fins. After you have performed this test, don't forget to empty the burnpot prior to starting again.

That doesn't seem to be the issue. I cleaned off the ESP probe, went over the whole boiler once more, cleaning every little corner I could. Still no luck. Again, there was some heat, but nothing would ignite. Now, I tried starting it in manual again, and it won't feed, so the fire's going to die. Lost.

 

[wil lanfear]

That doesn't seem to be the issue. I cleaned off the ESP probe, went over the whole boiler once more, cleaning every little corner I could. Still no luck. Again, there was some heat, but nothing would ignite. Now, I tried starting it in manual again, and it won't feed, so the fire's going to die. Lost.

Did the auger feed the pellets into the burnpot for the manual start or did you add the pellets to the burnpot? If pellets won't feed to keep the fire burning, sounds like the low pressure switch (vac switch) is not closing for whatever reason to power the auger and igniter. The vac switch has to close to power the auger. Check the vac switch with a multimeter making sure that it closes when the combustion blower is running. Also, check the auger motor to see if its is being powered, maybe something preventing the auger from turning.

 

[BRADLEY]

Did the auger feed the pellets into the burnpot for the manual start or did you add the pellets to the burnpot? If pellets won't feed to keep the fire burning, sounds like the low pressure switch (vac switch) is not closing for whatever reason to power the auger and igniter. The vac switch has to close to power the auger. Check the vac switch with a multimeter making sure that it closes when the combustion blower is running. Also, check the auger motor to see if its is being powered, maybe something preventing the auger from turning.

I shut it down and tried again. This time it fed in manual mode. I could still check the low pressure switch. I'll check that tomorrow . Thanks for keeping up with this

 

[SmokeEater]

SmokeEater, I did try cleaning out the vent pipe and boiler. Nothing was too bad to begin with, really. The one thing that makes me think that it's not a draft issue is that the flame looks fine when I run it in manual mode. Would this be the case if it were an issue of ash build up?

Bradley, sounds like you've cleaned and checked about everything, but haven't heard if you have checked the draft on TEST. Did you put a Magnahelic indicator hose through the 3/8" screw hole on the flame observation door and check to see that it was within range, I think just under .85" water column on test, and then on low draft about .35" on the column. I think my finned ignitor works so well because that draft is set correctly. Maybe that will give you some more clues when you check it.

 

[BRADLEY]

Bradley, sounds like you've cleaned and checked about everything, but haven't heard if you have checked the draft on TEST. Did you put a Magnahelic indicator hose through the 3/8" screw hole on the flame observation door and check to see that it was within range, I think just under .85" water column on test, and then on low draft about .35" on the column. I think my finned ignitor works so well because that draft is set correctly. Maybe that will give you some more clues when you check it.

I haven't done that. I do not have a Magnahelic indicator hose. Just out of curiosity, how can it be adjusted if it's off?

 

[Pellet_Dog]

I haven't done that. I do not have a Magnahelic indicator hose. Just out of curiosity, how can it be adjusted if it's off?

You adjust the low draft via potentiometer on the control board. The high draft is not adjustable but if it is over 0.85" water column (venting into a tall chimney for instance) Harman recommends putting a restrictor at the vent temination so that the 0.85" WC is not exceeded. If you don't have a magnehelic you can build a simple U-tube manometer with clear flexible tubing, place one end in the 3/8" port and measure the difference in column heights.

 

[wil lanfear]

That doesn't seem to be the issue. I cleaned off the ESP probe, went over the whole boiler once more, cleaning every little corner I could. Still no luck. Again, there was some heat, but nothing would ignite. Now, I tried starting it in manual again, and it won't feed, so the fire's going to die. Lost.

After reading all of your posts, IMHO, if the boiler is burning good in the manual mode and the issue is in auto mode when firing, it's not a gasket leak issue, could be an fuel-air issue with the amount of pellets in the burnpot prior to ignition. I mentioned in one of my posts how to make the adjustments for the quanity of pellets in the burnpot prior to ignition and if that has been done, ("That doesn't seem to be the issue") it kind of points the finger to being the pellets used. I went through the delayed ignition issue with my original finned igniter in my boiler, after making the dip switch adjustments for the pellets entering the burnpot prior to ignition that I mentioned, it resolved this issue. ( I have the pressure ignition now) I cannot stress enough the importance of getting the proper amount of pellets in the burnpot for a quick ignition.

 

[Centurion]

Hey Bradley, did you get the tech out to look at the issue?

 

[BRADLEY]

Hey Bradley, did you get the tech out to look at the issue?

I did! The cradle that holds the igniter was warped slightly, causing it to block some of the airflow needed to blow the heat up through the burnpot. The tech bent it back and I've ordered a new one to replace it. He says he doesn't see it too often. Thanks to everyone who helped out with ideas and suggestions. I don't think my boiler has ever been cleaner!

 

[Centurion]

Great news Bradley, a few of the folks were almost right on with their suggestions. I never would have expected this as a fix because I wasn't aware that the bracket could be bent out of position. Do you think that during the initial cleaning, prior to the problem, you may have bent it? Also, just an FYI, I have a brand new igniter with the fins that I'll never use so if you or anyone would like a back up please let me know.