Combustion Blower; Combustion Air Control - Monitor GF3800 Servise Manual

MONITOR HEATING SYSTEM
Section 1: Description IGFISOOI
1-33 COMBUSTION BLOWER
The Combustion Blower has a two stage intake
fan. The intake fan draws in outside air thru the
flue pipe for internal combustion.
Burner modes control fan speeds and the
Solenoid Damper in the Blower Casing. Those
functions are as follows:
COMBUSTION AIR CONTROL
Burn Mode Fan Speed Solenoid Damper
High High Off(open)
Low Low On(close)
Setting air flow for Solenoid Damper on Low
mode should read 5.5 ±0.5mmH2O for Nat. and
5.5±0.5mmHaO for LR
1-34 OVERHEAT PROTECTOR SWITCH
The normally-closed Overheat Protector Switch
safeguards the heaters against damage due to
overheating.
The Switch is rated 110°C (230T). Should a
Monitor overheat (internal temperatures rise be-
yond 110°C/230°F) switch will open to shut down
the heater. After extinguishing the flame, the
code [E17J is indicated in the digital display.
The Overheat Protector Switch will automatically
reset after cooling down. Once the heater has
cooled to 90 °C (194°F), the system can be re-
started. To restart the Monitor, proceed as fol-
lows:
A. Press ON/OFF Switch to OFF.
B. Allow heater to cool.
C. Troubleshoot the cause of the overheat.
D. Press ON/OFF switch to ON.
E. Proceed with normal operation.
1-35 THERMAL FUSE
Should Overheat Protector Switch malfunction,
and the heater be further overheated, the ther-
mal fuse (internal temperatures rise beyond 167
°C/333°F) melts and prevent further overheating.
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