On 11/8/2010 11:16 PM, Ed Pawlowski wrote:

Here's another wrinkle regarding gas vs oil: two years ago, the oil burner one
afternoon just didn't come on, even though the thermostat was calling for
heat. It did fire up again once I'd hit the reset - but what if I was away for
a few days? That could have been the nightmare scenario of a burst pipe (even
in the short section between where the water supply enters the house and the
house's main shutoff valve). Btw, the service guy that came a week later
didn't have any explanation as to how/why the burner failed to light. But he
did say that oil was less reliable in that way than gas.

My old boiler used to do that at time, the new one not at all, at least not
yet. Oil is more prone to go out on the reset than gas from my experience. If
you don't get ignition for any one a a myriad of reasons, it trips for
safety. Pump did not pump enough, igniter did not spark well enough, a piece
of carbon got across the tip of the igniter, etc.


Thanks. One thing I hadn't mentioned was that there was no smell of oil after
the failure to ignite incident. (I did swivel open the hatch at the time, and
I'd suppose it'd take a while for fuel oil to evaporate from the closed
chamber up the chimney.) So I'd guess that tends to argue against lack of
spark. Yet why would it not pump oil during the failed instance, but then
start right up later? I suppose it's possible that the burner motor wasn't
getting electricity momentarily, but the sensing-controlling circuits were...

There had been one occasion a couple of years previous, where the burner
wouldn't run at all until I'd removed certain wires and re-attached them to
their terminals. It is a damp cellar, too.