Re: oil furnace wont fire
Posted by Moore on November 07, 1999 at 22:24:16:
In response to Re: oil furnace wont fire
Hi, Go to the bottom of the page and look at last month's topics and find "oil furnace won't fire". Can you see your problem and solution there? When you have fuel and the igniter is good, you turn on the thermostat to call for heat and the burn does not begin, but the motor runs, you are experiencing an igniter trouble. Sometimes you can light the pilot manually with a match, which will heat the thermocouple long enough to open the supply valve, but it won't work again next time (or the time after that) because the igniter and pilot are designed to protect you from fuel buildup and explosion. The fuel product runs through the open supply valve to the control valve that has the thermocouple and or igniter connected to it. The fuel is stopped there. When you "call for heat" at the thermostat, it sends an electrical signal to the control valve to supply a very small amount of electrical current to the igniter to ensure that it is working, and when it receives an electrical signal that the igniter is ready to light the fuel, it then electrically opens a small valve to allow the fuel to proceed to the igniter and combust. Then the thermocouple wants to know that the flame is sustained long enough and hot enough to support a larger amount of fuel to begin the burn in the firebox. The control valve opens (electrically) a little more and a higher supply of fuel sets off a higher combustion rate in the firebox. Depending on the age and condition of your oil furnace, you should be able to see an actual red glow of the "glo plug" when the call for heat is made, and if you're close enough, you should then hear an electrical click of the solenoil in the control valve, that allows more fuel to flow, and more combustion. If you don't see the glo plug heat, you may have an electronic igniter that makes repeated electronic clicks to create a spark for ignition. That might be why you see no flame or flame like substance. I suppose I should ask if you can see spent matches or burnt paper pieces laying around in the firebox? If so you might actually require a pilot light instead of a glo plug or electronic igniter. If that is the case, try a long match (or a match held in needle nose pliers) to see if the pilot needs a light. (It could have been blown out by wind) If you do have a pilot light flame, but still no ignition, then look for the 1/4 inch tube that screws into the control valve and goes to the pilot light area. Thats a thermocouple, and it may be all that needs replacing.


: Dear Terry,
: My oil funace wont fire. yes there is fuel. I can turn it on at the thermostat and then turn on the circut breaker and it will run for a minute and then shut off. It does not try to fire at all, no flame ar flame like substance. Could it be the igniter? I have bled the lines. Thank you.




Replies to this post
There are none.