Re: fuel oil furnace
Posted by Moore on December 28, 1999 at 03:11:14:
In response to Re: fuel oil furnace
You're pretty bright! Fuel oil is thicher, heavier, more dense and has a different flash point than Kerosene. Fuel oil furnace burn nozzles are susceptible to clogging without clean fuel, and usually have a fine screen filter before the burn nozzle. Sometimes it only is filtered at the filltube of the tank (and that gets thrown away. The fuel shutoff valve stays closed when the transformer insn't calling for heat, and doesn't leak. Kerosene has more solvent properties and tends to thin out the laquer that has built up over years at the shutoff valve. That means that the valve is cleaner, and able to pass more fuel. When the transformer calls for heat, the valve opens to pass fuel oil which is thicker, but Kerosene which is thinner rushes to the nozzle and isn't fully burned so then builds up a slight pressure at the nozzle, and leaks through the valve to a low point under the transformer. You might stop the leak by switching back to fuel oil, but it'll take quite a while for the fuel oil to build up a laquer seal at the valve again. Please understand that you have a VERY SERIOUS FIRE HAZARD DANGER HERE! The pooled up Kerosene below the transformer stillgives off flammable vapors, even when the burner isn't firing. The fuel leak is probably at the shutoff valve seat packing, which was probably only designed for three to thirty thousandths small enough for fuel oil, but not tight enough for Kerosene which has a higher viscosity. Try changing out the shutoff valve.

: I live in Tampa Florida and for some reason even though it hardly gets very cold here the builder
: of our home (30 yrs old)
: installed a fuel oil furnance in the attic of the garage.
: the system was recently tested and we found several problems, plugged nozzle, flame sensor needed adjustment, ducts in firebox were clogged etc,
: we finally fixed the other problems and noticed the fuel was very low, since the system would not stay lit.

: new fuel was delivered and now the system fires up,
: but the fuel will begin to pour bach into the shaft below the tranformer and seems to come from the
: nozzle area, the funny thing is that it only leaks
: when the fuel is lit, not when the tranformer is bypassed. could I have the wrong fuel?
: do you need different nozzles with kerosene?

: Please Help

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