Technical data

GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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3.3 Ignition sequence manual versions
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. If for any
reason the pilot light is extinguished no attempt should be made to re light it within three minutes
a) Switch off the main electrical supply to the heater
b) Turn off gas supply to the heater
c) Remove side panel, and connect manometers to the gas supply test point and to the main burner test
point
d) Ensure outlet louvers 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) Turn on gas supply, and open burner viewing port
j) Depress and hold in control start button and test for soundness
k) Continue to depress start button whilst operating igniter until pilot light is present
l) Hold in start button for at least one minute to establish pilot - carefully release button confirming
presence of pilot
Warning
If the pilot fails to become established do not attempt to re light for at least three minutes , if the pilot is
established continue as follows :-
m) Close burner viewing port
n) Turn thermostat to the highest setting, and the main burner will light then re-open the viewing port and
check that the main burner is providing a good flame i.e. even, stable, and conical.
o) Check pressure readings on the manometers, and continue to let the heater fire for ten minutes
p) When the fan starts ensure that the direction of rotation is correct , and that the fan start is within two
minutes of burner ignition
Caution
If the fan fails to operate within approximately two 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.