This is a very common problem and question Asked here so im posting this on a thread.
There are several things to check but if you are sure the stove and flue are clean.
Burn pot is in correctly.
Ash pan and Front door close and have a good seal.
If you have a Whitfield Profile, Traditions or Optima I could be the PHOTO eye dirty or bad. This is another subject im not covering here. Please Check your owners manual Trouble shooting section.
Most other pellet stoves:
It could be the low limit or the high limit has tripped or failed.
Are you sure the Convection (room air blower) is working if that blower fails the stove will over heat and the high limit switch will trip killing power to the auger motor and or combustion blower.
This is a very common problem and no need to panic.
Check you owners manual for trouble light coded if any.
Most new stoves will flash a Feed light or heat level light and your manual will tell you what the problem is.
Low limit switch is a temperature switch mounted to the stove.
When stove is at its lowest operation temperature limit it will stop power to the blower(s) Shutting down the stove.
When you turn the stove off the auger shuts off but the blowers keep going.
When the low limit switch reaches around 100 Degrees then the blower(s) will shut off.
When you start you stove the Control board gives power to the Combustion blower for 15 minutes.
then stops giving power to the blower.
If the low limit reaches 120 or 140 degrees it will close (allowing power to flow threw it) and allow power to keep going to the combustion blower.
This is why it is called Proof of fire switch. It tells the stove that there is a fire and it can keep running.
If you run out of pellets or you shut the stove off the stove will cool down and after the limit switch reaches around 100 Degrees it will OPEN up and not allow power to flow to the blower(s)
It could be the Hight limit also:
If the stove reaches over 200 or 250 degrees at the high limit switch. (because of a room air blower failure) the switch will open and not allow power to flow to auger, Combstion bower or control board. Depending on stove.
<example form a Breckwell owners manual>
STOVE SHUTS OFF AND THE # 3 LIGHT FLASHES:
8. The Proof of Fire (POF) thermodisk has malfunctioned:
Temporarily bypass the POF thermodisk by disconnecting the two
brown wires and connecting them with a short piece of wire. Then
plug the stove back in. If the stove comes on and works, you need
to replace the POF thermodisk. This is for testing only. DO NOT
LEAVE THE THERMODISC BYPASSED. Your blowers will never
shut off and if the fire went out the auger will continue to feed pellets
until the hopper is empty if you leave the POF thermodisk bypassed
9. The high limit thermodisk has tripped or is defective
Wait for the stove to cool for about 30 - 45 minutes. It should now
function normally. If not use the owner’s manual to locate the high
limit thermodisk. To test if the thermodisk is bad, you can bypass it
as described previously for the POF thermodisk.
</end of example>
More info on limit switches
https://www.hearth.com/talk/threads/13408/
More info on Whitfield stove with a Limit switch (not photo eye stoves)
http://www.hearthtools.com/parts/lowlimit.htm
More info on Breckwell limit switches
http://www.hearthtools.com/parts/Breckwell_help.htm
Enviro Trouble shooting guide down load at the top of this page
http://www.hearthtools.com/enviro_pellet.htm
Avalon Trouble shooting Guides at the bottom of this page
http://www.hearthtools.com/parts/900_ps_1990_97.htm
There are several things to check but if you are sure the stove and flue are clean.
Burn pot is in correctly.
Ash pan and Front door close and have a good seal.
If you have a Whitfield Profile, Traditions or Optima I could be the PHOTO eye dirty or bad. This is another subject im not covering here. Please Check your owners manual Trouble shooting section.
Most other pellet stoves:
It could be the low limit or the high limit has tripped or failed.
Are you sure the Convection (room air blower) is working if that blower fails the stove will over heat and the high limit switch will trip killing power to the auger motor and or combustion blower.
This is a very common problem and no need to panic.
Check you owners manual for trouble light coded if any.
Most new stoves will flash a Feed light or heat level light and your manual will tell you what the problem is.
Low limit switch is a temperature switch mounted to the stove.
When stove is at its lowest operation temperature limit it will stop power to the blower(s) Shutting down the stove.
When you turn the stove off the auger shuts off but the blowers keep going.
When the low limit switch reaches around 100 Degrees then the blower(s) will shut off.
When you start you stove the Control board gives power to the Combustion blower for 15 minutes.
then stops giving power to the blower.
If the low limit reaches 120 or 140 degrees it will close (allowing power to flow threw it) and allow power to keep going to the combustion blower.
This is why it is called Proof of fire switch. It tells the stove that there is a fire and it can keep running.
If you run out of pellets or you shut the stove off the stove will cool down and after the limit switch reaches around 100 Degrees it will OPEN up and not allow power to flow to the blower(s)
It could be the Hight limit also:
If the stove reaches over 200 or 250 degrees at the high limit switch. (because of a room air blower failure) the switch will open and not allow power to flow to auger, Combstion bower or control board. Depending on stove.
<example form a Breckwell owners manual>
STOVE SHUTS OFF AND THE # 3 LIGHT FLASHES:
8. The Proof of Fire (POF) thermodisk has malfunctioned:
Temporarily bypass the POF thermodisk by disconnecting the two
brown wires and connecting them with a short piece of wire. Then
plug the stove back in. If the stove comes on and works, you need
to replace the POF thermodisk. This is for testing only. DO NOT
LEAVE THE THERMODISC BYPASSED. Your blowers will never
shut off and if the fire went out the auger will continue to feed pellets
until the hopper is empty if you leave the POF thermodisk bypassed
9. The high limit thermodisk has tripped or is defective
Wait for the stove to cool for about 30 - 45 minutes. It should now
function normally. If not use the owner’s manual to locate the high
limit thermodisk. To test if the thermodisk is bad, you can bypass it
as described previously for the POF thermodisk.
</end of example>
More info on limit switches
https://www.hearth.com/talk/threads/13408/
More info on Whitfield stove with a Limit switch (not photo eye stoves)
http://www.hearthtools.com/parts/lowlimit.htm
More info on Breckwell limit switches
http://www.hearthtools.com/parts/Breckwell_help.htm
Enviro Trouble shooting guide down load at the top of this page
http://www.hearthtools.com/enviro_pellet.htm
Avalon Trouble shooting Guides at the bottom of this page
http://www.hearthtools.com/parts/900_ps_1990_97.htm