Furnace Won't Ignite

 

Originally posted by elko.mike The idea of opening the valve slowly is interesting, as it seems some deliberate set of actions should result in the furnace lighting every time.

Take at least a minute to open the tank's valve to prevent triggering the safety valve.  Then light the stove and you should be all set.

Thanks. Lighting the stove burners did the trick. Much appreciated.

My saga continues.  I turned the gas off last night.  This morning I turned the gas back on, lit a stove burner, and tried to lite the furnace.  The blower started, I heard it spark one or twice, and it didn't lite.  I waited a while for it to lite, but it stopped sparking and the blower ran on.  So I turned it off and waited for the blower to stop.  When it did, I turned the furnace on again.  I heard it spark a few times, but again it didn't lite.  After a few minutes I turned the furnace off and waited for the blower to stop.  On the 3rd try I didn't hear it spark and assume it has locked out.

My goodness, but this seems harder than it needs to be.  I called the dealer and he told me to lite a burner -- same tip that was provided here -- and then to lite the stove.  I told him I had done that and it didn't work.  I then asked for specifics about the process of purging the lines.  He told me to turn on the gas (I am), lite a stovetop burner (I do), wait for the flames to be nice and blue (I didn't), and then the furnace should lite. 

So I'm cycling everything now to test this new process.  I recycle by turning off the gas, lighting a stove burner until it goes out, pull the fuse for the furnace (my lame attempt to get it completely recycled), and then to go through the process to lite the furnace.

I think folks advising me to get a ceramic heater have it right, but it is my nature to run a problem to ground.  After all I'm an engineer and a problem to an engineer is like a fire hydrant to a dog.  Nuff said.

I am pretty sure I have a resolution.  It was a purging problem in two parts: normal purge procedure unknown originally and once it was discovered an impatient operator wasn't performing it properly. 
Yet again I turned off the gas and lit the stove burner until it went out.  That should bleed most of the gas from the line.  After a couple of hours elapsed, I took the fuse from the furnace (as I've been doing all along) to set it to a known initial state.  Then I turned on the gas and went inside where I lit a burner on the stove.
It was at this point my process changed.  My old process was to flip the switch on the furnace as soon as the stove burner lit.  It was downhill from there. 
My new process, upon advice from the service tech, was to let the burner run until the flame was good and blue.   I estimated (should have measured it) that to be about 30 seconds.  When ALL of the yellow left the burner then I turned it off.  After burner flame was good and blue I tried the furnace and it lit right away.  Thanks to all for the encouragement and advice.  It's time for a good scotch.
Mystery solved!  An impatient operator was failing to FULLY purge the gas lines.