2010 King 5510

Have a 3yr king 5510 that was given to me about 1ry ago.Prior user got tired of it not working correctly and swapped me 23" LCD PC monitor for it.He said that combustion motor just ramped up and down while in use and did not burn right.He changed every motor/pc board and even the vacuum switch to try to get it to run like his other pellet stove. He ended up just removing wires off combustion motor and run direct to outlet and said stove worked better that way but still not like it should.He ended up tossing it into his garage and just buying another brand from local seller. I reconnected the exhaust motor as it was from factory and installed it.Unit has elbow exiting unit into a 3ft pipe then another elbow into 25' well cleaned chimney.

Unit still surged the combustion motor on and off. Is this the way it supposed to run because it doesn't operate properly this way.At start up it will start up as it should...burn correctly but once it gets hot enough for room blower to come on the combustion motor goes into a surge on and off mode.If you hit the off button combustion motor will operate normal and stove will shut down as it should.Another thing is that the blower speed doesn't affect it at all , neither does the room blower.It will allow you to select 1-9 & Auto(both on draft fan and blower)but will not effect operations of the motors.He did have board replaced under warranty to try to correct this issue but it did not correct combustion motor issue.They also replaced the combustion and room blower but thats when he just hooked direct to a/c and gave up.I can get unit to work fine direct and just damper incoming air but that will cause premature failure of combustion motors and really would like to get it working correctly as it should.

What could be the reason after start up and room blower comes on, the combustion motor goes into a on/off/on/off run more instead of just slowing down to match heat setting?

Thanks

Ok I understand start up and up to temp. Unit gets all the way up to operating temp.been on for days now and auto light blinks,display with the HR-2(which the - isn't flashing showing it is operating on selected heat range chosen). Have had stove going for a while (used last year)and know how to "tune" it in with combustion fan wired to outlet .I get tired of having to shut stove off then 10 mins later have to unplug the exhaust motor /shut top door because it was wired to outlet due to to pc board ramping combustion motor on and off once room blower came on.I can get stove to burn as it should for 7-10day(removing ash every 3-5days and cleaning glass).But this is while combustion is not being controlled by the pc board and wired directly into outlet.I put exhaust blower back to being controlled by pc. the very min the room fan cuts on the exhaust goes into a on/off mode(motor surges from hi to almost off constantly)This is not proper operating and causes soot,unburned/half burnt pellets to be forced out of pot.have tried fine tuning it but because motor operates this manner it will not burn properly or provide proper heat .Blower motors have been r/r as was vacuum switch and even removed fitting to chamber to ensure not blocked.
They did replace the board but prior owner say he thought it was a used one the service dept sent him. When that didnt solve it they sent him new motor.I think instead of buying a brand new board for it I will just put in 5 min timer/relay to just shut fan down after shut down pressed.I understand leak issues on this unit and have read up 1yr ago and sealed it up properly.Owner said that unit ran ok until few months in when it started soot/black glass and exhaust motor on/off issue.I figured someone else here has came across this issue but guess not.I will just give up and operate stove how it seems to want to be ran...with draft fan not controlled by the pc board which i think is the real problem.Unit runs perfectly if draft is not controlled by the pc board.Not that it matters anymore but ironic it says its a us a made stove but every part in it is made in a foreign country and shipped to us.Hopefully the steel is still made here and is what they are claiming is made in USA.Maybe should have label assembled in USA only.Thanks for your time