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Marra Forni
10310 Southard Drive Beltsville, MD 20705 1.888.239.0575 [email protected]
GAS BURNER SERVICE
GAS BURNER MAINTENANCE
Caution:
If the gas supply pressure is below its
specified range during adjustment, an overfire
condition could result when normal pressure
returns, particularly if the regulator adjustment
screw is bottomed out. ALWAYS confirm that
at least the minimum rated gas pressure is
being supplied to the burner during regulator
adjustments, and NEVER bottom out the
regulator screw.
Caution:
Explosion hazard. Can cause serious
injury or death. This device can malfunction if
it gets wet. Never try to use a device that has
been wet or submerged.
Caution:
If flame is observed when burner is
on standby, or if the ignition spark or gas valve
operator comes on before the motor reaches
operating speed, immediately turn off the
Main Manual Shut-off Valve and power to the
burner. A condition has developed that must be
corrected. Contact a service technician.
Caution:
If PROPANE is used and the burner
is located in a confining space, install a gas
leak warning device. Propane gas is heavier
than air and can settle in low areas or confined
spaces. This can cause a dangerous condition.
--If the pressure regulator fails to maintain a
constant manifold gas pressure within ±0.1”
W.C., and it is confirmed that the inlet gas
pressure to the Combination Gas Valve is a
steady 14.0” W.C. minimum with the flame on,
the regular portion of the gas valve is defective
and the entire gas valve must be replaced.
XIV - Electronic Control
Operation-Power Up/Standby: Upon applying
power (24v) to 24VAC, the control will reset,
perform a self-check, initiate full time flame
sensing, flash the diagnostic LED for up to
four seconds, and enter the thermoscan state.
Maintenance
---The motor features permanently lubricated
ball bearings and requires no routine oiling or
maintenance.
---Check burner flame periodically. A proper
natural gas flame will appear blue at the burner
face with orange/yellow tips. If the flame is too
rich, it will appear billowy and yellow with hazy
tips. If too lean, it will appear short and all blue.
If the flame does not appear proper, contact a
qualified service technician.
Caution:
If the combination gas valve has
been moved or replaced, perform testing for
leaks with the burner running.
Caution:
If leakage through the gas valve
occurs on standby, as evidenced by the
presence of any flame, the entire gas valve
needs to be replaced.
---Heat Mode: when a call for heat is received
from the thermostat, the control will check
the internal blower motor interlock switch for
normally open contacts. The combustion
blower is then energized and once the internal
blower motor interlock switch contacts close,
a pre-purge delay begins. Following the pre-
purge period, the gas valve is energized and
spark will commence for the trial ignition period.
---When flame is detected during trial for
ignition, spark should shut off immediately while
the gas valve and combustion blower remain
energized. The thermostat, internal blower
motor interlock switch, and main burner flame
are constantly monitored. When the thermostat
is satisfied and the call for heat ends, the main
valve is de-energized immediately, the control
senses the loss of flame signal and initiates
an (optional) post-purge period before de-
energizing the combustion blower.
---Failure to Light (Lockout): Should the main
burner fail to light, or flame is not detected
during the trial for ignition period, the control
will go into Lockout. The valve will be turned
off immediately, and the combustion blower will
be turned off following an optional post purge
period.
