STA-RITE SR200NA Service Manual page 48

SECTION FOUR – Routine Maintenance and Professional Servicing
Combination Gas Control Valve
(Continued from the preceding page)
To Air Flow
Switch
To Air Flow
Switch
To Gas
Valve Vent
Connection for
Service
4. Install a 1/8"NPT barbed fitting into the
'PRESSURE TAP' port. Use a flexible tube to
connect it to the l l l l o o o o w w w w side of a differential pressure
gauge or a slope gauge. This gauge will measure
low (outlet) pressure.
N N N N O O O O T T T T E E E E : : : : If you are using a slope gauge or a differen-
tial pressure gauge of less than 3"capacity, close the
shutoff valve of the gauge to avoid pulling the liq-
uid out of the gauge when the blower starts.
5. Disconnect the tube from the Gas Valve 'VENT'
port. Connect it to a tube with a tee running to the
high side of a differential pressure gauge and to the
blower's air orifice grille (See Picture, above).
6. Turn on the Manual Gas Shutoff Valve.
7. Before operating the heater, leak-test the heater and
all its gas connections with soapy water.
R R R R i i i i s s s s k k k k o o o o f f f f f f f f i i i i r r r r e e e e o o o o r r r r e e e e x x x x p p p p l l l l o o o o s s s s i i i i o o o o n n n n . . . . N N N N e e e e v v v v e e e e r r r r t t t t e e e e s s s s t t t t
f f f f o o o o r r r r g g g g a a a a s s s s l l l l e e e e a a a a k k k k s s s s w w w w i i i i t t t t h h h h a a a a n n n n o o o o p p p p e e e e n n n n f f f f l l l l a a a a m m m m e e e e . . . .
8. Turn on electricity to heater and start the pump.
S S S S a a a a f f f f e e e e t t t t y y y y P P P P r r r r e e e e c c c c a a a a u u u u t t t t i i i i o o o o n n n n s s s s : : : :
Risk of fire or explosion if
Combination Gas Control Valve is incorrectly
adjusted. If it is necessary to adjust the gas valve,
this must be done only by a qualified service
agency.
NOTE:
omitted for clarity; make this test with all gas piping
connected (as for normal service).
To High Side
of Differential
Pressure Gauge
To Low Side of
Differential
Pressure Gauge
Connection for
Test
4-16
The gas piping and unions have been
9. Turn on the heater.
10. After the burner lights, verify that the supply pres-
sure is within the range 4"to 14"wc. If the supply
pressure drops below this range when the burner
ignites, the gas line capacity may be inadequate,
and should be increased. See Page 2-13.
11. With the burner still on, open the shut-off on the
gauge. The pressure gauge should then read .2"
±.1"wc. (Since the pressure tap is connected to the
low side of the gauge, the pressure is actually nega-
tive.) If the pressure is outside the range listed, call
the factory at 1-800-752-0183. Do not try to adjust
the pressure yourself.
12. If the pressures are within the limits given above,
shutoff the heater, replace the tube to the Blower
Inlet, replace the heater covers and cycle the heater
to check for proper operation.
Note: Your model may be
equipped with an ON-OFF
toggle switch instead of
the Gas Control Knob.