Technical data

In order to test that all controls are in good
working order, the control sequence should
first be tested with the gas supply turned Off.
Ensure gas isolating cock is in the Off
position
Warning
If during the following sequence of operations
the heater fails to operate correctly the fault
should be traced and rectified before
proceeding, if necessary referring to section
5.0 fault diagnosis.
a) Switch off the main electrical supply to the
heater
b) Turn off gas supply to the heater
c) Open side panel, and connect manometers
to the gas supply test point and to the main
burner test point
d) Ensure outlet louvres are correctly set
e) Ensure fan rotation is not impaired or
obstructed
f) Set room thermostat to its lowest setting
g) If a time switch is fitted ensure it is set to
an on period
h) Switch on electrical supply
i) Use leak tester to test for soundness on the
unions and pipework
j)
Operate the heater through the installed
control system.
On start the signal will activate the flue venter
for a pre purge period and in turn will make
the air proving switch, once made, the air
proving switch will complete the circuit to the
control box and after a 40 second Delay the
automatic control should attempt light the
burner, because the gas is turned off and
flame cannot be established , the control box
will go to LOCKOUT.
k) Reset the control on completion of dry run.
l) Open gas cock
m) Operate heater through installed control
The flue venter will pre purge the heater and
in turn operate an air proving switch which
completes the electrical circuit to the control
box after a 40 second Delay the control will
open the gas solenoid valve and the main
burner will light.
The flame can be observed at the burner
manifold, check that the burner is providing a
good flame i.e. even and stable.
n) Check pressure readings on the
manometers, and continue to let the heater
fire for ten minutes
o) When the fan starts ensure that the
direction of rotation is correct , and that the
fan start is within 2 minutes of burner ignition
Caution
If the fan fails to operate within approximately
2 minutes and the heater goes to overheat it
will shut down through breaking the circuit to
the gas valve, the cause must be ascertained
and rectified before re-ignition.
Once the limit thermostat has tripped out it
must be manually reset to allow re-ignition to
take place.
p) After ten minutes check burner head
pressure is as specification - adjust as
necessary by removal of the gas pressure
adjustment cover, and using a screwdriver
turn the adjustment screw on the governor as
follows: Clockwise to increase.
Anti clockwise to decrease.
q) Check that the gas pressure remains
satisfactory for all appliances on the same
circuit
r) Undertake combustion tests checking CO
CO
2
and efficiency (see section 7.0)
CO should not exceed (20PPM)
s) Check that the burners are extinguished
when the thermostat is set to its lowest
setting, and then remove the manometers.
t) Turn the thermostat to its highest setting to
re light the burner and replace the adjustment
screw cover
On completion mark the gas valve
adjustment screw with paint/sealant to
prevent tampering with valve
u) Turn the thermostat to its lowest setting
and shut off the gas supply at the gas control
valve, allow the fan to continue to run until the
heater is cooled sufficiently for the fan to shut