Instruction manual

8. The burner

continues to

run, but the

fan cycles on

and off.

• Gas manifold pressure

• Fuel supply pressure and volume

• Fan sensor

• Heater Control Unit (HCU)

• Use a low pressure gauge (0-15 inches of water column) with 1/8” NPT inlet.

Install gauge in the pressure tap port located on the output side of the gas

valve. Run the heater. Adjust the pressure by turning the pressure adjusting

screw (located on the input side top of the gas valve) until the gauge reads 3”

W.C.(Propane) & 3.2” W.C.(Nat Gas). Refer to pipe sizing charts in the Heat

Wagon Engineering Guide. Heater requires 9-14” W.C. inlet pressure.

• Refer to pipe sizing charts in the Heat Wagon Engineering Guide.

Heater requires 9-14” W.C. inlet pressure.

• On the heater control unit (HCU) disconnect the wires from terminals X12 and

X13. Using an ohm meter, check the resistance between the two wires for a

reading of 8K-15K ohms. If the test falls out of this range, replace fan sensor.

• Turn the 3-position main switch to the fan position. If the blower runs, check the

fan sensor. If it is good, replace the HCU.

G175 TROUBLESHOOTING

Symptom

Possible Causes P

ossible Solutions