MACH
®
Gas Fired Boiler
30
3.9
S
AFETY
C
HECKS
The following checks of safety systems must be made before putting the boiler into operation.
Before firing the boiler refer to Sections 4.1 and 4.2 for information on the use of the controls, lighting, and shut-down
procedures.
Never attempt to operate a boiler that has failed to pass all the safety checks
described below.
If a control setting is changed manually during testing, return the control to its
original setting.
NOTICE! If the expected error code(s) do not appear, call for qualified service.
3.9.1 Test of Ignition Safety System
Test the ignition system safety shutdown as follows:
1) Cycle the boiler on by generating a heat request. (See Section 3.10)
2) Place the boiler in operation at the high fire setting
.
3) Smoothly close the downstream manual isolation valve to reduce the gas flow and cause flame failure.
4) The display will show LOCKING FLAME FAILURE indicating a flame failure. The lockout will remain until the
control is reset.
After completing this test, turn off the boiler and open the downstream manual isolation valve and turn the boiler back
on.
3.9.2 Test of Low Water Cut-off
The boiler is furnished with a probe-type low water cut-off in the outlet nozzle. Test as follows:
Push and hold the red “Push to test” button for at least 5 seconds. A manual lockout reset error, displaying
LOCKOUT LOW WATER LEVEL on the display panel, should occur. The LED indicator on the low water cut-off will
no longer be illuminated.
(Optional Test Method)
First turn the boiler off, and then turn the pump off. Isolate the boiler from the system. Drain the water level below the
low water cut-off probe. Turn the boiler back on. It should not operate, and a manual lockout reset error, displaying
LOCKOUT LOW WATER LEVEL on the display panel, should occur. The LED indicator on the low water cut-off will
no longer be illuminated.
Return the system to normal operation by refilling and restarting the boiler and pump.
3.9.3 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 LOCKING HIGH LIMIT 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.