STA-RITE SR200NA Service Manual page 46

SECTION FOUR – Routine Maintenance and Professional Servicing
Combination Gas Control Valve
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The Combination Gas Control Valve is located on the
right side of the heater on top of the combustion
chamber.
F F F F u u u u n n n n c c c c t t t t i i i i o o o o n n n n
The Combination Gas Control Valve incorporates dual
gas shut-off valves and a negative-pressure regulator.
The negative-pressure regulator controls the outlet
pressure to slightly below the reference pressure sup-
plied to the regulator diaphragm by the vent line. For
proper operation, the regulated pressure at the outlet
manifold of the valve must be 0.2"wc below the refer-
ence pressure, and the gas "vent" tap must be connect-
ed to the Mixer inlet.
S S S S e e e e r r r r v v v v i i i i c c c c i i i i n n n n g g g g P P P P r r r r o o o o c c c c e e e e d d d d u u u u r r r r e e e e
See next page for instructions on checking the gas pres-
sure through the Combination Gas Control Valve.
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 : : : :
Fire and explosion hazard. Do not adjust
the gas flow by changing the regulator setting. To adust
the gas flow, the Gas Orifice must be replaced with an
orifice from a gas orifice replacement kit (see "Gas
Orifice", Page 4-17, for more information).
Fire and explosion hazard. This appli-
Combination Gas Valve
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Replacing the Combination Gas Control Valve:
1. Close the external manual gas valve.
2. Turn off the pump and all electrical power to the
heater.
3. Disconnect the gas supply piping at the external
union.
4. Disconnect the Combination Gas Control Valve
from the Air/Gas Mixer at the closest union.
5. Disconnect the plastic tube from the Combination
Gas Control Valve "VENT" port.
6. With piping on both sides of the Combination Gas
Control Valve disconnected, slide the Combination
Gas Control Valve out of its support bracket.
7. Replace the Combination Gas Control Valve by
reversing Steps 1-5 above.
8. Test for gas leaks with a soapy water solution.
N N N N O O O O T T T T E E E E : : : : When reconnecting the Combination Gas
Valve to the gas supply-piping, use a thread sealant
approved for use with natural gas and LP gas (such as
RECTORSEAL).
ance is equipped with an unconventional gas control
that is factory-set with a manifold pressure of -.2 inches
wc. Improper installation, adjustment, alteration, ser-
vice, or maintenance of the Combination Gas Control
Valve can cause fire, explosion, death, personal injury,
or property damage. Installation or service must be
performed by a qualified installer, service agency, or
the gas supplier. If this control is replaced, it must be
replaced with an identical gas control.
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