If you have a gas furnace and have seen it lighting and going out time after time before it finally locks out, then you know the frustrations of wondering what the problem could be.
Heat is there, it is in your sight, you can feel it for a few seconds and then, puff, it goes out and all you know is that the house is getting colder by the minute!
What are some of the problems that can cause this to happen…
- There is a problem with the venting of the furnace.
- Water in the flue pipe.
- Bee’s nests, rodents and other critters getting stuck in the flue pipe.
- Objects getting sucked into the intake pipe such as plastic bags, dandelion, and yes children hiding Easter eggs…
- The flame sensor is dirty or moved so that it does not touch the flame.
- The pressure switch has just plain gone wacko…does not close anymore.
- Circuit board failure, the flame is lighting, sensing, but the control board still thinks not and shuts the gas valve off.
Now how do you know what is the problem with YOUR furnace? The process of elimination in most cases is the best method to determine what is going on.
- Check both the intake (if you have one) and exhaust pipes carefully! Believe me this can be challenging sometimes! Finding problems can be very time consuming. Listen for water in the pipes. Take each one off at the furnace for a short time and see if it runs with them off. Do NOT leave the exhaust off for more than a short period of time!! Carbon Monoxide will kill you!
- Remove the flame sensor and clean gently with a bit of cloth or scrub lightly with steel wool. Do not use rough abrasives or sand paper.
- Checking the pressure switch can be tricky. If you do not find any other problems you can jumper the wires of the pressure switch AFTER the vent motor has started and then see if the furnace stays burning. You can not leave them jumper because the circuit to the wires needs to be opened after each cycle of the furnace for it to retry for ignition again.
- If all else fails it may be the circuit board. They can and do go bad, but make SURE that you are positive that it is the problem before getting another one. They are a bit pricey and they are YOURS after you purchase it. They are not returnable in most cases.
This will give you guidelines that will get you going in most cases, if you have flame for a bit and then it goes out. If you are experiencing no flame at all it still could be some of these possibilities. There may also be some other possibilities that will take a trained professional to figure out. http://www.fixya.com/support/r4015846-furnace_ignitor_care_home_furnacehttp://www.fixya.com/support/r3583678-hot_air_furnace__how_to_troubleshoot_thehttp://www.fixya.com/support/r4016017-find_air_conditioning_heating_furnacehttp://www.fixya.com/support/r3583636-home_heating_furnace_repair___how_do_you