FloAire FAV-M - Manual (Page 36)

36
Symptom Possible Cause Field Test Remedy
Continuous high fire
(electronics OK) Foreign object holding valve
open or plunger jammed Inspect: plunger should be
smooth and clean, and
operate freely in the solenoid
valve. Clean or, if necessary,
replace plunger
Incorrect maximum
fire Inlet pressure too low
Incorrect outlet pressure
adjustment of pressure
regulator
Hunting Read pressure at inlet to
modulating valve using a
manometer with unit
operating at high fire.
Pressure should be equal to
the sum of the outlet pressure
setting plus pressure drop of
the valve.
Read manifold pressure using
manometer and compare with
recommendation of the heater
manufacturer.
Adjust sensitivity control
counter clockwise. Increase inlet pressure,
if possible.
If flame stabilizes, adjust
sensitivity control to
maintain an even flame
Erratic or pulsating
flame Erratic air patterns or improper
TS114 location
TD114 wiring is run next to
high voltage switching circuits
causing induced voltages
Faulty amplifier or erratic
voltage supply Connect test resistor as
described in the preliminary
circuit analysis section. Turn
TS114 selector dial so heater
goes though its entire
modulating range.
Temporarily remove TD114
from its remote locating and
reconnect at valve location.
Observe heater observation.
With test resistor connected
as described in the preliminary
tests, and TD114 locally
connected as described above,
turn TD114 selector dial
though entire modulating
range. Observe voltage
across modulator terminals. If the flame is steady
thought-out the entire
modulating range, the
TS114 must be
relocated.
If smooth operation
results, isolate TD114
wiring from source of
induced voltage.
If erratic or unstable
voltages are obtained
throughout the
modulating range, the
amplifier may be
assumed defective.
Replace. If erratic
operation is noted only
over a small range, the
voltage source may
contain surges.
Incorrect discharge air
temperature Incorrect wiring
Improper TS114 location Check installation according to
the diagram in the preliminary
circuit analysis section.
Sensed temperature does not
represent average discharge
air temperature. Correct wiring
Move TS114 to location
where average
representative
temperature can be
sensed.