furnace dose not light
I have aatwood 8500 IV that wont light light off , 3 red light indicat ignition lockout fault,what should I check or replace
Forum Discussion
There are many causes.. For example if the blower does not blow hard enough (low battery, Bad connection, Bad motor, Blocked air duct, Faulty sail switch) the sail switch will never close and the unit will time out.
if there is no LP flow (Empty Tank, valve off, faulty regulator, bad solenoid valve, clogged orifice) then it can not light
If the ignition system does not make sparks (Spark gap too wide, Wire or connector fault (Bad) bad control board)
And in this last case, it will iight...for about 3 seconds 3 times, If the control board fails to sense the flame (Bad thermocouple (Flame sensor) Bad wire or connection, bad control board) it will lock out.
On the model you have I believe there is a single high-tension wire that carries both the spark voltage (Roughly 1,000 wolts) and the flame sense voltage (Roughly 1/2 volt, or .480 volts or 480mV if you want to know the peoper voltage).
I should point out I have the same furnace.
In my case it was the last fault. It would light for 3 seconds.. i checked everyting. And I mean EVERYTHING several times over.. Wound up ordering a new Dinsosaur Fan-50 control board from American RF in California (not to be coufused with the company that changes my oil, American RV, Burton, MI). and the problem vanished.
IF that is what your problem is this is my theory.
The change over from SPARK generation to Flame sense went wrong and it hit the flame sensor chip with the kilovolt spark power, Frying it soundly.
I suspect Dinosaur boards thinks this is what happened too.. WHY? Well on the Dino Fan-50 is a device, a Gas Discharge Tube. Often used to protect senistive electronics from over voltage.. This is a very robust protective device,,, I can only think of one reason for it to be there. They have the same theory I do so put in a protection device.
The quality of the Dinosaur board was very impressive.
if there is no LP flow (Empty Tank, valve off, faulty regulator, bad solenoid valve, clogged orifice) then it can not light
If the ignition system does not make sparks (Spark gap too wide, Wire or connector fault (Bad) bad control board)
And in this last case, it will iight...for about 3 seconds 3 times, If the control board fails to sense the flame (Bad thermocouple (Flame sensor) Bad wire or connection, bad control board) it will lock out.
On the model you have I believe there is a single high-tension wire that carries both the spark voltage (Roughly 1,000 wolts) and the flame sense voltage (Roughly 1/2 volt, or .480 volts or 480mV if you want to know the peoper voltage).
I should point out I have the same furnace.
In my case it was the last fault. It would light for 3 seconds.. i checked everyting. And I mean EVERYTHING several times over.. Wound up ordering a new Dinsosaur Fan-50 control board from American RF in California (not to be coufused with the company that changes my oil, American RV, Burton, MI). and the problem vanished.
IF that is what your problem is this is my theory.
The change over from SPARK generation to Flame sense went wrong and it hit the flame sensor chip with the kilovolt spark power, Frying it soundly.
I suspect Dinosaur boards thinks this is what happened too.. WHY? Well on the Dino Fan-50 is a device, a Gas Discharge Tube. Often used to protect senistive electronics from over voltage.. This is a very robust protective device,,, I can only think of one reason for it to be there. They have the same theory I do so put in a protection device.
The quality of the Dinosaur board was very impressive.
