On Sat, 05 Aug 2006 22:16:34 GMT, "Pete C."
wrote:

John wrote:

"Pete C." wrote:

trimmed
The owner was also directed to have the boiler serviced as soon as possible.

That is / was *not* an explosion, not even close. I don't think a
blowback on a residential boiler has ever injured anyone, much less
killed them. Certainly it will scare the **** out of them and perhaps
teach them not to keep messing with the thing if they don't know what
they are doing.

Oil burners do *not* have blowbacks on their own, they have had the
safety devices to prevent that for decades. Blowbacks occur when someone
keeps pressing the reset button ignoring the warning not to press it
more than once. Oil burner controls from the last couple decades have
incorporated a "three strikes and you're out" lockout to prevent this.

Ok, that's not the case. You can reset ANY oil flame safeguard
relay control as many times as you like.

The nucleus of gas vs. oil residential heating safety lies in the
control methodology of the times.

Oil burners are direct fired. The full fuel output is ignited by a
strong arc. There is no pilot light. If it does not ignite, there is
approximately 10 seconds worth of atomized oil spray
inside of the combustion chamber. Flame detection is performed by a
Cad Cell.

Until recently, most all gas furnaces used a small pilot light to
achieve combustion, which in turn ignites the main burners. More of
today's furnaces are direct light off such as the oil burner, however
modern flame safeguards strategies are applied to bring an acceptable
level of safety to the gas burner.

There are better controls available for domestic oil burners
however they have not found their way into the residential product
lines.

Proportionally, there are many more instances of delayed ignition in
oil, then fuel gas.


So oil heat is not "safe" under your definition.

http://www.newburyfd.org/responding_...er_emergen.htm

That is an interesting link however you probably didn't read it
thoroughly:

This other bit:

"Fuel oil comes in several grades, number 1 to 5 grade oil, and has the
following general fire hazard properties: a flashpoint of 1007F to
1507F, a flammable (explosive) range of 0.7 to 5 percent when mixed with
air, and an ignition temperature of 4947F."
should give a bit of a reminder on just how difficult it is to get oil
to burn and the near impossibility of igniting oil spilled from a tank
leak.

Oh it won't burn pretty, but it WILL burn under far less stringent
conditions as these.



-zero