Tools Required; Theory Of Operation - PHP Heat Wagon LVF90A Service Manual

Low Pressure Oil Heaters have many small parts: Start by making a clean
work area. This will give you an area to layout the disassembled parts. Gather
the tools required before work is started. You will need the following: 1/4"
and 5/16" Nut drivers, 1/8" Allen wrench, common size open end wrenches
and screwdrivers, 0-15 PSI Pressure gauge (HA1180), 0-200 high pressure
gauge (G14494), flashlight, oil drain pan, .001 to .1 Feeler gauge,
AC250V/RX1 Volt/Ohm meter,and a few gallons of fresh clean kerosene.
In addition to the tools mentioned above, every shop should have an HA1170
Tester. It is equipped with a three-position switch (off, solid, flashing) for a
red LED and a set of alligator clips.
The HA1170 Tester is designed to take the guess work out of repairing HSI
heaters. The HA1170 Tester will troubleshoot HSI photocells and Ignition
Control Boards. It is an essential tool when telling the difference between a
good part and a bad part in HSI heaters. Specific instructions on using the
HA1170 Tester are found in the Photocell Section and the Ignition Control
Board Section. The HA1170 Tester can also be used to test components for a
heater with solid state ignition, making it more practical to own.
Low Pressure Theory of Operation
There are four basic systems working together to achieve proper operation:
• Fuel system
• Air system
• Electrical system
• Combustion system
An air pump; driven by the back end of the motor shaft forces air through a
tube and out the nozzle head. The moving air over the center hole in the noz-
zle creates a pressure differential in the burner head causing fuel to be drawn
from the tank through a fuel tube and out the center hole of the nozzle.The
fuel is mixed with the air swirling around the side of the center hole in the
nozzle turning it into a fine mist.
Combustion air is introduced into the combustion chamber by a fan driven
by the front end of the motor shaft. The remaining air from the fan is directed
over the outside of the combustion chamber. This air mixes with the heated
air from the combustion chamber and is ejected as clean heated air.
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Preparation/Tools Required