______________________________________________________________________ Hey guys, any help appreciated here. I have a 19 year old Bryant furnace model 398A…Deluxe gas fired condensing furnace. I woke up this morning to a 57 degree house. and hint of gas smell. I went to the basement to what was up with my “Deluxe” furnace, I found that the inducer was running and the electronic ignition was electronicly igniting…snap, snap, snap, flash, flash, flash, constantly. With the smell of gas I deemed it obivous that I should probably turn the gas off, I did so. I could hear what seems like gas shutting off, but everthing else still doing the same. I let the inducer run a while longer to clear out any gas that may be around yet. I installed an add on wood burner about two years ago, so I opeted to utillize what is not my back up heat, which in hind sight was probably not my wisest move, considering the presence of gas smell, but some how mananged to start a fire with no explosion. I am a complete DIYer and will do anything possible not to pay someone to do what I can do with a little bit of research. That’s when I came across this site, and here I am. From doing some reserch on the internet I am wondering if maybe I have a bad pressure switch. Although I am very mechanicly inclined, as I run the situation through and through my head, I am baffled at how, if the I could smell gas, and it seemed as if gas was moving from when i shut off the valve, and I could hear and see spark from the ignitor, how is it that the gas I could hear and smell was not igniting, even if it didn’t ignite in the way way it was designed to ignite? Why is my furnace sill in one piece? So I went back down and with the thermostat on off, I turned the gas valve back on (the one on my gas supply pipe) and sure engough gas started flowing and I could smell gas, which leads me to beleive that maybe I have a gas control problem, but again why would it no light? I don’t get it, please help me out, what do I have to do to get this working agin. I know at 19 I sould probably be thinking it’s time for a new one, but would really like to limp through the next couple weeks of unseasonably cold wether, and wait until this summer to install a new one, at which time I would try and tackle the feat on my own.
I don’t know if it is a factor or not, but about 2 months ago my blower went down, and I was awaken to the cooking smell of my furnace, I replace that moter only to have the bearings go out in that one a week later, and again with the cooking. Please any insite would be greatly apprecieative. Jason PS I am almost postive I don’t have a diagnostic flasher on my unit. Replies: papashaq “No burner ignition on bryant furnace” , posted Mon 21 Mar 12:01 ______________________________________________________________________ Well been reading formums for a couple of hours now, and haven’t found any real leads yet, but I went down to put some wood in the fire and thought just for S & G’s I would fire up the furnace and see what happens…I cranked up the thermostat ran downstairs, and turned one the gas, looking in the peephole and this time saw a constant flame, more like a pilot light, which I didn’t see this morning, just saw the spark, which I am guessing lites the pilot. As normal the inducer ran awhile than the burners lit up….all seems normal. So not real sure on what the deal is, but input would be great, as I would hate to go to bed tonight, thinking it was just a fluke, since I don’t beleive in flukes and have it happen again, but something for serious this time…let me know what you think…thanks. esaheatac “Re(1):No burner ignition on bryant furnace” , posted Mon 21 Mar 14:46 ______________________________________________________________________ That furnace pre-dates the current hot surface ignitor technology and uses an ignition control that we have always called a 3-wire pilot burner. It’s nothing more than a single pole, double throw heat actuated switch built onto a pilot burner. The initial signal goes up yellow (common) to the switch and comes back down green to the spark generator. At the same time the pilot valve on the gas valve assembly opens allowing gas to flow through the pilot tube and hopefully be lit by the spark. Once the pilot flame lights, it eventually heats up the switch to the point where signal changes over from the green wire to the white wire which goes to the main gas valve thus firing up the burners. These pilot burners are notoriously finicky, and tend to require replacement on a regular basis. Yours didn’t light the pilot for some reason, even though it was generating a spark. papashaq “No burner ignition on bryant furnace” , posted Mon 21 Mar 16:32 ______________________________________________________________________ Thank you for your replay, it was very educational to me, and now all those wires make sence…but one thing still boggles me, if there was spark there, in that chamber, and it was pumping gas there to light a pilot, and god knows how long this was pumping gas in before I woke up, don’t you think that eventually some gas had to reach that spark? and ignite? It was constantly trying to light that pilot? I could smell gas in the house, and saw the spark was mabye that ignitor not working, pumped gas into where it goes, the furnace realized it was not igniting, and stopped the gas after enogh went through to smell up the house? And then the ignitior started working, and was never told to stop trying to work, but was just not sending gas to it? I don’t know…but then when I had the furnace thermostaticly turned off, (still power to the furnace, thermostat switched from heat to off) and I turned on the gas line out side the furnace it was still pumping gas and I coould smell it almost instanly? Make any since?