Patterson-Kelley MACH-05 User Manual

Page of 59
  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. 
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.