Proheat M125 - Manual (Page 82)

NOTICE
Inspect Proheat Control Module (PCM)
to ensure that all connectors have
plugs or have an electrical connection.
5-5 PROHEAT M-SERIES G-II PCM SERVICE MANUAL
• Disconnect all external harnesses at the PCM.
• Disconnect fuel supply line.
• Remove Burner Head Assembly.
• Remove Ignition Module Electrodes and Flame Shield.
• Ensure the Temperature Sensor is disconnected from the PCM
Note: Disconnecting the Temperature Sensor will cause the heater
to go directly into purge when started and prevent combustion.
• Install air pressure test gauge (PK0036).
• Install ignition electrodes.
• Reconnect Power & Switch Harness only.
• Start heater and read the air pressure on the gauge.
• If the measured pressure is not within specification, refer to items
4.2.4 and 5.2 of the M-Series Service Manual.
• Check the air pressure setting as described on page 4-9.
WARNING
Flammable. Point Nozzle away from
face, open sparks and flames.
MODEL AIR PRESSURE (DIAPHRAGM COMPRESSOR)
M50 6.0 ± 0.1 PSI (41.4 ± 0.7 kPa)
M80/90 2.9 ± 0.1 PSI (20.0 ± 0.7 kPa)
M105/125 3.65 ± 0.1 PSI (25.1 ± 0.7 kPa)
11. Electrical System
• Check the internal and the external wire harnesses for missing or
damaged seals, damage and corrosion. Replace if required. Check
PCM for missing electrical connector plugs. Replace as necessary.
12. Timer/Toggle Switch Supplemental/Preheat
• Check heater operation under specified heater on signals.
13. Operation Test
• Run the system for at least 15 minutes or until the heater cycles
“OFF” and then “ON” again.
• Inspect the following during the test:
a) Combustion process.
• For smoke and raw fuel odor from the exhaust pipe.
• Fuel system leaks.
• If there is a problem go to page 4-5 to page 4-27, Steps 1 to 7.
b) Coolant system:
• For leaks.
• For correct system heating process. Go to page 4-24, Steps 1 and 2.