I keep ending up with a burn pot full of unburned pellets. I've replaced the igniter and cleaned the exhaust, as well as the entire stove. The igniter does seem to get hot, but nothing burns. It's been suggested that maybe there is not enough voltage getting to the igniter. Any other thoughts or suggestions? Thank you
Harmon PB 105 trouble with ignition
- Thread starter BRADLEY
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
- Status
iceguy4
Minister of Fire
Sometimes a dip switch adjustment will cure it. with smaller pellets I've seen mine "over feed" too soon. It will actually snuff out the small fire. Do you have a pressure igniter or finned? the compressor filter could be restricted. I cant stand any pellets going unburned to rather then to mess with the dip switches, I chose to hook up a simple but affective "dump zone"( 120 v0lt ac NO relay tied into the blue wire...then I simply ran wires to my basement zone and piggybacked it on the thermostat wires) and run it in "manual" I'm gonna include you in a discussion where we are discussing just that...
Darn jobs are a problem! Hard to say what is going on with his boiler without more info. Serial number would be helpful to see what version he has. If he replaced the ignitor it could be he put in the low volt one and he is dumping too many pellets in and it cycles out. He cold always try lighting it manually to make sure it's just an ignition problem and everything else works ok.
Sorry to have not been able to reply. Was tied up yesterday. I have a finned igniter.
It was manufactured in 2008. I've checked the resistance of the igniter and got close to 50 ohms. So the igniter itself is fine. I've been running it on manual and it despite going out once over the past couple of days, seems to run fine in manual mode. What is the overheat dump zone?
I will check that. I did scrape the burnpot clean and vacuum the entire boiler. I will try clearing out the holes though too. Thanks
Bradley, do you have the manual for the boiler? It shows you two areas that fines can collect. Make sure both are clean and the plates are screwed on tight. Does you control board light for the ignitor come on when you try starting in auto mode? Does it stay lit for approx 40 minutes and time out with no fire? Have you cleaned the fins on the combustion fan?
Yes to all of the above except the fins on the combustion fan. They don't look to bad though
if the little door to the igniter area is not on straight, or the thumb screws are not tight then air is escaping through it, that can prevent ignition. If the air intake flapper is stuck you can get same...if everything checks out then there's always a chance you have pellets that are resistant to ignition for whatever reason. Try a diffeent pellet to see if you have same result.
iceguy4
Minister of Fire
It most likely went out because it went into "over heat" . When the PB is in manual and it overheats it will shut down...Since its in "manual" it wont restart.
Over heat dump zone = some place to dump excess heat generated the boiler "idling" The blue wire(in the PB 105 junction box) will become hot 120v AC during an over heat. you can use that wire to power a circulator pump to send the heat to some place besides in the boiler...OR you can use that blue wire to power a relay to activate a zone ( I chose my basement zone)
An example of a overheat zone is in the owner's manual. It's purpose is to help bleed off excess heat when your boiler, due to idling, overfire or other factors, gets too hot. It's sort of like another heat zone. there is a wire in your electric box (pretty sure it is blue) that is for the overheat, or dump. I didn't install an overheat zone in my system, but I run in auto mode so when there is no call for heat at the thermostat my boiler goes to sleep. In manual mode it idles so there is more potential for it to overheat.
Is this a new to you boiler? Has it every started correctly? If so, when did the problem start? You mentioned you recently replaced the ignitor. Fortunately, I've never had to replace mine so I don't know if there could be a positioning issue associated with the install. If it is getting hot and there are both pellets and air flow you should get ignition within a few minutes.
Is this a new to you boiler? Has it every started correctly? If so, when did the problem start? You mentioned you recently replaced the ignitor. Fortunately, I've never had to replace mine so I don't know if there could be a positioning issue associated with the install. If it is getting hot and there are both pellets and air flow you should get ignition within a few minutes.
I'm was almost through 2 tons of these pellets when the issue arose. I do need to get more, so I will try a different kind
SmokeEater
Feeling the Heat
I recently had a similar problem but the pellets were burning but also not completely and I had a pile of unburned pellets in the ash pan. I also noticed my stack temp was lower than "normal of about 280 degrees. The burn pot holes looked fouled so I cleaned them all with a small drill bit that fit. Forgot the size. The stove shut down and I thought it was out of pellets, but there were still a small amount in the hopper. The status light indicator was showing 6 blinks. That the combustion probe was out of temp. When I opened the ash door to clean, the ash pan was HOT with the smoldering pellets creating lots of heat and a loss of oxygen in the burn area. I decided to do a major clean and pull it all apart. The vent pipe was very full of fly ash, maybe as much as 3/4 inch on all walls, combustion fan area also. Cleaned the small area in front of the fan through the access door and there was a good deal of ash in there too. Didn't have to do this clean last year until end of season, but it came early this year. Now I will plan on a mid season cleaning. I cleaned the combustion fan blades carefully with a knife and it took a while, but worth it. Put it all back together and it lit right up and has been burning the pellets before they get to the drop end of the burn pot. All it took was a good cleaning.
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?
The boiler is about 6 years old at this point. Just enough to be out of warranty! I don't think it's a positioning issue though with the igniter.
iceguy4
Minister of Fire
Manual recommends dump zone anyway...because it can still overheat in "auto mode" ...Like if its ripping and the call for heat ends. It could overheat doing its "shutdown " thing..
If the flame looks good ...more then likely your problem is with "start up" This will put unburned pellets in ash pan. I'm reluctant to adjust my dip switches...they are there to adjust how much time is given to light the pellets before sending more pellets into the mix. I have witnessed mine put out the freshly started pellets by over feeding pellets too soon. My solution...Manual till spring ...then I will look at dip switches
Mr._Graybeard
Feeling the Heat
I had an ignition problem with my boiler last night. The pellet selection is reduced this late in the season, so I was testing out a cheap pellet I had rejected last season because ... I had trouble with ignition in a cold burn pot. I thought I'd give them a second chance this year but got similar results.
My friend and neighbor Jay Z is burning them successfully in his Fahrenheit furnace and likes them, but they just don't light quickly enough in the PB 105 if the burn pot is cold, IME.
My friend and neighbor Jay Z is burning them successfully in his Fahrenheit furnace and likes them, but they just don't light quickly enough in the PB 105 if the burn pot is cold, IME.
iceguy4
Minister of Fire
To all finding pellets in ash pan and don't know why....well I had the same problem ...till I caught my stove "in the act" Its hard to determine why sometimes...did it not light? did it over feed?... Well I caught my stove in the act. It started as usual , but TOO quickly it over fed pellets and smothered the fire. My research, from members of this forum and " wil lanfear" ...the Dip switches adjust the delay of pellets to prevent "snuffing out" the fire. This compensates for pellet size too(smaller pellet size = longer time to ignite)
Test what? There are dip switches (not sure cuz I have never layed eyes on them myself) search this forum for" dip switches" ...Look for a PB owner named "wil lanfear"( search his posts) He has direct knowledge of the switches and where to set them to delay the feed of pellets to let the fire get going fully.
- Status
Similar threads
