Harman Advance Manual Mode no keep alive burn

  • 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.

forjack842

Member
Nov 26, 2015
15
Lancaster, CA (93536)
Been troubleshooting this for a while now. I have my Advance setup with a remote thermostat switching the Harman thermistor in and out controlling room temp from about 15ft away, stove feed at 4, Room Temp at High, Temp Dial at 85, thermostat controls room temp at 75 +-1. . Been operating fine for 10 years plus now. Last couple weeks I've had to run in Auto mode because the keep alive burn dies out requiring the Auto mode be set to re- ignite the pellets. It appears the Augur Feed motor is not being powered but Feed LED is lighted, possibly due to low draft sensor switch being open. However switching to Auto and everything works fine. Since the Low Draft Switch is necessary in both Auto and Manual to enable the Feed motor and igniter I'm guessing the Draft switch is not seeing sufficient draft (vacuum) provided by the Combustion Fan in Manual Maintain mode.
Question... In Auto mode is the Combustion Fan speed faster RPMs than in Manual Maintenance mode? Example, In Manual, not providing heat, I see the Combustion motor running at reduced speed, LED Off, but sufficient to cause the Low Draft Enable that allows the control board to maintain the keep alive burn. I have the "Low Draft Setting" at its max increasing
TIA,
Jack
 

Mt Bob

Minister of Fire
Oct 31, 2013
3,953
park county montana
Yes, the fan is probably at it's slowest in fire maintain mode. It also changes depending on stove settings, and probe readings. Anyway,I would jumper vac switch, and see if it stays running. Also make sure fan spins freely.
 

forjack842

Member
Nov 26, 2015
15
Lancaster, CA (93536)
Yes, the fan is probably at it's slowest in fire maintain mode. It also changes depending on stove settings, and probe readings. Anyway,I would jumper vac switch, and see if it stays running. Also make sure fan spins freely.
Hi Bob,
I have a new draft switch and have been holding off looking for any data on Combustion Fan speeds. I have a clip leads and was going to do that jumper as you said. Thought I bounce the symptoms off the forum before I do that just in case.
Thank You Sir!
 

Mt Bob

Minister of Fire
Oct 31, 2013
3,953
park county montana
NP. Yes, many believe a Harman fan only runs at one speed. I'm sure you know to clean out the hose, and, because of age, clean out the nipple to the firebox. Although there have been cases of fan motors running slow because of control board. But you know the first steps.