Trane TR250 Service & Installation Manual page 34

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6. Take a pressure reading with the heater running, the value should agree with those in Table 15. If
the pressure is within the range of 1.8" - 2.0" w.c. (natural) or 6.8" - 7.0" w.c. (propane), then no
further adjustment is needed.
7. If the gas pressure does not meet the above requirements the regulator must be adjusted.
8. Gas pressure regulator adjustment procedure:
a. Remove the screw cap over the regulator
b. Turn the regulator adjustment screw clockwise to increase pressure and counterclockwise to
decrease pressure.
c. Replace the screw cap over the regulator adjustment screw.
WARNING EXPLOSION HAZARD: Do not remove the 1/8" pipe nipple with the
valve in the "ON" position. The valve
removed. Removal of the nipple with the gas valve "ON" could
resulting in severe injury and/or death.
9. Remove the 1/8" pipe nipple and replace the 1/8" pipe plug. If proper pressure cannot be achieved
by adjusting the gas valve regulator, the installer must contact the gas supplier and request that the
inlet pressure to the heater be set to within the gas pressure range shown in Table 15.
WARNING EXPLOSION HAZARD: Gas pressures in excess of those listed in Table
15 could cause a gas leak or diaphragm rupture. Gas leakage could cause an explosion
resulting in severe injury or death.
Table 15: Correct Gas Pressures
Fuel
Manifold 1.8" - 2.0" w.c. 6.8" - 7.0" w.c.
Inlet, minimum
Inlet, maximum
10.5" w.c.
Natural Propane
4.5" w.c. 9.0" w.c.
13.0" w.c.
adjustment screw (see Figure 22).
must be in the "OFF" position when the nipple is
cause an explosion