Patterson-Kelley MACH-05 - Manual (Page 23)

MACH® Series Gas-Fired Boiler Installation
Page 19
3. Smoothly close the downstream manual isolation
valve to reduce the gas flow and cause flame
failure.
4 The display will flash E-02 indicating a flame
failure. The E-02 lockout will remain until reset
on the display.
After completing this test, turn off the boiler and open
the downstream manual isolation valve.
3.11.2 Test of Low Water Cut-out
The boiler is furnished with a probe-type low water
cut-out in the outlet nozzle. Test as follows:
Operation of the switch can be checked by first turning
the boiler off, and then turning the system pump off.
Isolate the boiler from the system pressure. After
isolating the system, drain the water level below the
low water cut-out probe. Turn the boiler back on. It
should not operate, and a manual reset lockout
displaying E 12 on the display panel will occur. The
LED indicator for Low Water cut-out will no longer be
illuminated.
Return the system to normal operation and restart the
boiler. Refer to Section 4.2.1.
3.11.3 Test of High-Limit Control
Fire the boiler and test the high limit control as
follows:
With the main burner operating, turn down the
temperature setting on the "high-limit" thermostat until
the main burner shuts off. A manual reset lockout
displaying E 12 on the display panel will occur. The
high-limit switch must be manually reset prior to
resetting the boiler at the display panel. Readjust the
high-limit thermostat to the desired setpoint.
3.11.4 Test of Gas Pressure Switch
Low Gas Pressure Switch
The boiler is furnished with a low gas pressure switch.
The operation of this switch must be checked by
slowly closing the main gas cock while the burner is
operating. The switch should shut down the main
burner. When the gas pressure switch opens, a
manual reset lockout displaying E 12 on the display
panel will occur. Upon re-opening the main gas
cock, the E 12 indicator will remain on until the
display panel is manually reset.
High Gas Pressure Switch
C450 units equipped with a high pressure switch
must be checked by closing the downstream gas cock
while the burner is operating. The switch should shut
down the main burner. When the gas pressure switch
opens, a manual reset lockout displaying E 12 on the
display panel will occur. Upon re-opening the gas
cock, the E 12 indicator will remain on until the
display panel is manually reset.
C750,C900 and C1050 units equipped with a high
pressure switch must be checked by closing the
downstream gas cock with the boiler off. When the
boiler is starte , it should enter its normal starting
cycle and fail on high gas pressure when the gas
safety valves open. The high gas pressure switch
actuation is evident when a manual reset lockout
displaying E 12 on the display panel occurs. Upon
re-opening the gas cock, the E 12 indicator will
remain on until the display panel is manually reset.