Tony Sivori wrote:
[Note the cross post. Follow-ups set to alt.home.repair]

Ah, what luck. My furnace quit working last night. This is a long
rant and a "poor me" post, not a request for help. So if you're not
to inclined to point and laugh at the clueless, you might not want to
read on.

I thought the trouble was the thermostat. The Lux 500 had given me
trouble many times before; it showed the low battery warning even
with fresh batteries literally if I touched it wrong when adjusting
the temperature.

A few days ago I noticed that it sometimes the Lux thermostat let the
temperature fall five degrees below the set point before the furnace
(Ruud Silhouette II) ran. I'd have to turn it to off and then back
on, then it would run ok for a few days. I was concerned about the
Lux crapping out entirely, so I picked up a Honeywell RTH110B at
Lowes. I didn't get around to installing it.

Last night (New Years Day) at around 10 PM the temperature was in the
upper teens, the coldest night we'd seen this year in Louisville. My
furnace stopped running. I assumed it was the thermostat.

The symptoms we if I turned the thermostat to "off" then back to
"heat" the furnace would begin to start. I'd hear the whine of the
power vent. The the igniter (it's a pilot-less furnace) would glow,
and then the natural gas would start. The gas ignited fine, all
burners looked perfect, but it ran for about five seconds then
chopped off abruptly. This cycle repeated two or three times then
nothing until I turned the thermostat off and then on again.

It was getting cold in the house, so I decided that now was a great
time to replace the thermostat. :-) I turned off the breaker to
the furnace, and swapped the Honeywell for the Lux.

It was the first time I swapped a thermostat. I was disappointed at
the flimsiness of the connections of the Honeywell. The screws were
too damn tiny, and the plastic back flexed so bad I feared it would
break as I tightened the terminal screws. But nothing broke, and I
completed the swap with apparent success.

Hoping I hadn't bought a dud thermostat, I turned the power back on
and then turned the Honeywell to heat. The power vent started and I
figured I had a winner. Good thing, as it took an hour to swap the
thermostat and the house was even colder.

Guess what, the furnace did the same thing it did with the old Lux.
Start, light three times, each time quitting after five or ten
seconds.

At this point I was really frustrated not to mention worried. I had no
means of alternate heat. No kerosene heater, no electric radiator.
Stupid of me, but I'd been in the house since May and it was just one
more thing I had meant to do. With visions of frozen pipes in my
head, I wondered if the 24 hour Wal-Mart was open at 11:30 PM on New
Year's night.

And I had to be at work on Wednesday, so I was looking at missing
work to let in a repairman. And would I be lucky enough to get a
repairman before the pipes burst?

Before I left to find out if the Wal-Mart was open, I decided to try
my luck with a Google search of the furnace symptoms. Fifteen minutes
later, I knew that it probably the flame sensor. I even found photos
of what it looked like. Plus some model specific information that my
furnace has eyes, that like the flame sensor, need periodic cleaning.

Another hour and a half later, the sensor was lightly sanded with fine
paper, and the eyes were gently wiped with a paper towel. I also
wiped the sandpaper grit off the flame sensor. It is now three hours
since the furnace failed. My house is now in the mid 50's and if it
weren't for the stress and the exercise I'd be cold.

Power back on, thermostat on. The furnace starts, lights ... and
stays lit and produces most welcome warmth.

The Internet. Secret lover. Fixer of furnaces at all hours and on
holidays too. Is there anything it cannot do?

--
Tony Sivori

So why are you telling us / or me this Tony? You just needed to bang out
some letters to the world?

--
Zyp