Figure 4-13.H-type downdraft hood.
UNIT HEATER MAINTENANCE
Oil-fired space heaters require periodic cleaning.
Frequent checks must be made to ensure that
equipment is kept clean, because accumulations of
carbon and soot can cause disastrous fires. Units
should be moved when they are cleaned, so they can be
cleaned inside and out. Accumulations of soot must be
removed from inside the fuel pipe. All piping and
tubing should be kept clean and free of oil drippings.
The pot or burner assembly may be cleaned
without removing the heater. When cleaning this
component, remove it through the front door opening
and clean all the air holes using a soft copper wire. Do
not remove all the carbon from the bottom, because a
small accumulation of carbon at the bottom acts as a
wick and helps maintain the pilot light. In replacing the
burner assembly, make sure both sides of the burner
are tightened equally, so the top of the burner and the
fire-retardant gasket are set firmly against the flue
In checking the constant-level control valve, check
the operation of the heater through a complete cycle of
operation from the pilot fire position to the main fire
position, and then back to the pilot fire position. Set the
control valve, if it is the manual type, to high fire; and if
equipped with a thermostatic device, set the thermostat
above room temperature. If the heater fails to operate
properly through the cycle, check the constant-level
control valve and follow the manufacturer's
instructions for disassembly and cleaning. A parts
breakdown of the valve is shown in figure 4-14.
Some of the common problems with pot and sleeve
oil burners, gas-fired space heaters, their causes, and
possible remedies are listed in appendix II, tables I and
What are the basic types of unit heaters?
How are electrically powered space heaters
When you select and install an electric space
heater, what factor should be paramount?
On vented gas-fired space heaters, it is
important to install the venting system properly
to minimize the effects of what problem?
What type of burner is used in an oil-fired space
What is the only safety device on an oil-fired
To maintain a constant draft for the burner of an
oil-fired space heater, what device should you
install in the chimney?
Figure 4-14.Constant-level control valve.