The appearance of these readings on the corresponding gages is illustrated in Figure 26.
Figure 26. Correct gage readings.
The correct readings for the gages on the control panel of .the M2 water heater are the following: water
pressure gage, 60-155 psi; fuel pressure-gage, 60-75 psi at startup; water temperature gage, 40 - 190
degrees Fahrenheit. The operating valve of the fuel pressure will vary depending on the fuel used to fire
the M2 water heater.
During operation of the M12A1 PDDA, you should maintain constant surveillance of the apparatus. Be
alert for leaks, unusual noises, loose fittings, or any abnormal conditions. Specific items and the checks
to be made are discussed in the following paragraphs.
With the engine and the pump operating, rotate the throttle to see that it increases or decreases the
engine's RPM. For quick speed control, press in on the button in the center of the knurled knob and pull
out or push in the knob to increase or decrease engine RPM.