SERVICE BULLETIN
ON
THE
OXYGEN DEPLETION SYSTEM
In 1983 all gas space heaters were
required by U.S. government regulations to be equipped with an OXYGEN DEPLETION
SYSTEM (ODS). The ODS pilot burner is a highly sensitive device which is
designed to shut off a heating appliance if the oxygen level in an area falls
below 18%. The standard oxygen level is 21%. Because
the ODS is a high sensitive device it must be properly maintained and adjusted.
PERIODIC CLEANINGS IS A NECESSITY DUE TO ACCUMULATIONS OF LINT AND DUST IN THE
PILOT BURNER! There are also times when the air shutter must be adjusted in
order to facilitate proper flow to the pilot burner.
CLEANING THE ODS PILOT
BURNER
A. The pilot will burn
correctly, as shown below, when it is properly cleaned.
(straight flame
across the tip of the thermocouple)
B. The pilot will look like
this if it is not burning correctly (due to collection of lint).
(yellow flame is
raised from tip of thermocouple)
How to clean lint and dust
out of the pilot burner:
The lint can be blown
out by using a small tube, hose, drink straw or can of compressed air. Direct the air source into the
flame end of the pilot burner. Gently lift the air shutter, being careful not to
permanently bend the bimetal. While gently lifting the air shutter back, blow
high pressure (or whatever pressure is available) air toward the lifted air
shutter.
BE CAREFUL NOT TO TOUCH OR
DAMAGE THE RUBY ORIFICE
ADJUSTING THE BIMETAL AIR
SHUTTER
Casual pilot outage is
sometimes caused by the air shutter opening too wide. When this occurs excessive
air enter the pilot, causing the flame to lift off the thermocouple. Correction
can be made by adjusting the tip of the shutter bimetal. The gap between the
bimetal and the pilot tube should be 1/4" (+\- 1/16"). This gap can
easily be corrected with a screwdriver inserted between the bimetal and the
pilot tube. 
ODS
Pilot
Assembly
Bimetal Air Shutter Adjustment
|
