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Octopus furnace See
Gravity warm air heating
system.
Ohms The unit of measure
for resistance.
Oil burner nozzle A
device located in the blast tube which shoots out oil
particles into the
firebox.
Open ground Where an
outlet is not grounded.
Open return In the
basement, an opening in the furnace or return ducts for
collecting
return air. Most often prohibited.
Open system A hot water
system that has an expansion tank open to the atmosphere
and
located above the highest radiator in the home.
Open valley A valley
where the roof covering stops short of the valley and
the flashing is
visible.
Operating controls On a
gas water heater, a control unit with a thermostat and
gas
controls.
Outlet An electrical
connecting device providing receptacles into which
appliances can be
plugged for power.
Overflow An auxiliary
drain in bathtubs and some sinks.
Overfusing
Using a fuse on a circuit that is larger
than the wire's capacity. Not allowed.
Overload protection device
A fuse or breaker which will break the
circuit when it
overloads.
Overshooting A condition
when a house is heated higher than the thermostat is set
for. |