I tried this over at alt.hvac and was redirected here:
I have a Janitrol (I know, it came with the house) gas heater.
A couple of times in the past, it has stopped working and the tech came over
and replaced a flame sensor.
One of the times, the tech simply sanded the sensor and said this would
extend the life - he said you could maybe get one or two sandings out of
one, and get an extra season (or worst case, get you through the night, or
day until the tech could come out with a new one). He kind of showed me how
to do this as I watched.
Each time, the heat has had this problem, it started igniting the burners,
which burn for about a minute, and then go off, presumably because the
sensor is not seeing any flame.
So a couple of weeks ago, it started again (it's probably been 1.5 to 2
winters since the guy was last out, but I can't remember if he replaced, or
sanded last time). It sounded the same to me - I can hear them downstairs,
and when I go up in the attic to check, I can see the flame come on, and
shut off after about a minute. Once this starts, it just continuse this
cycle every couple of minutes. So basically I get lukewarm air blowing out
Now this time, it came on more gradually (though because I'm more aware of
it, I might have just caught it earlier on - in the past I didn't know until
I woke up and it was 60 degrees in the house), and if I cut the thermostat
off, and then back on, it would blow heat the first cycle. After that,
lukewarm air. However, it ran last night and though the house got down to
65, when I woke up this morning it was blowing hot - so it must be coming on
intermittently still (BTW, it's been warm here, so we haven't needed to run
it, plus the holidays, so I've been putting off calling the tech - even
tonight, at 2:00 AM which it is now, it has not come on (in fact we just had
a thunderstorm in the middle of winter! that's highly unusual).
So I went up tonight, took out the flame sensor (I cut power of course) and
took some 320 grit sand paper (which is all I had) and lightly brushed it
(no pressure by hand, just from the paper) like the guy showed me.
Now I have "repairer's remorse".
I read on the oh so accurate internet that I should use emory paper or light
steel wool to do this.
Anyways, my questions come down to this:
How long should a flame sensor last (I seem to be getting 2-3 seasons out of
Is a flame sensor something I should be buying and installing myself?
If so, is self-diagnosing this problem based on my previous experience wise?
Or, should I just put one in every season regardless (as if I was putting
new batteries in my smoke detectors every daylight savings time change?)?
They seem to be ranging from 10 to 20 bucks, or as high as 134 bucks - so
something funky is going on there - I realize various models will vary in
price, but are these things a "maintenance" item, or something I should be
leaving to the pros?
Will having a service agreement with a tech include cleaning of a sensor, or
will something else they do help to extend its lifespan? (I would assume
they'd replace it if it fails, but is it something they can test and will
replace or recommend to replace on a regular check up?)
Finally, If I've sanded the sensor, and the heat seems to be running
normally (if it ever actually gets cold here in the next couple of days - it
should be in the 30s at night now - it's not), should I get the tech out
here anyway (OK, I know it would be a good idea) or is this something that I
can blow up the house with. That is, if I sanded a sensor too much, would it
see flame when there is none, and let the gas come out, rather than just
always assuming there's no flame and cut of the gas - which is what it's
supposed to do - and which is what happens when there's carbon buildup -
sees no flame even though there is some and shuts off as a safety
precaution. Seems like it's a device that if it senses no flame, either
because there is none, it's covered in gunk, or the wire's disconnected, it
will shut off the gas. Right?
Thanks for any assistance you can offer,