Proheat M125 - Manual (Page 49)

Figure 4-11: Pressure Relief Valve adjustment.
PRESSURE RELIEF CAP
LOCK NUT
PRESSURE RELIEF
VALVE BODY
4-12 PROHEAT M-SERIES G-II PCM SERVICE MANUAL
m) Adjust the air pressure if necessary by releasing the lock nut and turning
the pressure relief cap as shown in Figure 4-11.
If the pressure cannot be set to the correct setting, read Section 5.3.
Rotary Vane Compressor Service and Vanes Installation to check operation.
If required, replace rotary vane compressor as shown on page 5-7.
n) Tighten the lock nut to 50 in-lbs ±5 in-lbs (5.6 Nm ±0.6) and ensure the
air pressure did not change after tightening the lock nut.
o) Turn the heater off. Wait until Cool Down (Purge) mode is complete (approx.
3 minutes).
p) Remove the Pressure Gauge Adapter and Harness. Lubricate Air Pressure
Relief Valve O-ring with diesel fuel and re-install the Air Pressure Relief Valve
in it’s original location. Torque to 25 in-lbs ±3 in-lbs (2.8 Nm ±0.3 Nm).
Reconnect the Ignition Module and Fuel Solenoid connectors to the G-II PCM.
Re-install the Flame Shield, the Ignition Electrode Assembly and Burner
Head onto the Heat Exchanger.
q) Connect the Power, Dual Mode Temperature Sensor & Coolant Pump electrical
connections to the heater Burner Head and reconnect the fuel line.
r) Activate the heater with the remote switch and observe operation. The
heater should run smoothly with no smoke although there may be some
hesitation initially due to air in the fuel line.
s) Remove the remote switch and re-connect the control connection.
If a Start diagnostic code is indicated, proceed to Step 5.
NOTICE
All plugs/harnesses must be rein-
stalled into the G-II Proheat Control
Module (G-II PCM) before heater
goes back into service.