Fulton Vertical Tubeless (FT-A) Thermal Fluid (hot oil) Heater - Manual (Page 75)

Questions? Call (315) 298-5121, or visit us online at www.fulton.com
SECTION 4
FTA-IOM-2013-0227
MAINTENANCE
4-15
TABLE 10-J - HIGH GAS PRESSURE SWITCH TROUBLESHOOTING
Problem Potential Remedy
Gas pressure setting
on the main regulator
is too high
With unit running at high fi re, make sure that the modulated gas valve is at full open.
Since unit lights at low fi re, it may be necessary to increase high gas pressure setting or jumper contacts to allow unit
to modulate to where modulation gas valve back pressure is lessened.
Check net last elbow gas pressure and compare to factory test fi re sheet. Net gas pressure is running gas pressure
minus p urge pressure. Make sure net pressure reading is within .2” w.c. of factory reading. If there is a diff erence,
adjust main regulator. Adjust for proper combustion throughout range.
Low fi re gas valve
setting is too low
Because the sensing point of the High Gas Pressure Switch is upstream of the modulating gas valve, the highest
pressure read will occur during low fi re.
Check net last elbow gas pressure and compare to factory test fi re sheet. Net gas pressure is running gas pressure
minus purge pressure. Make sure net pressure reading is within .1” w.c. of factory reading. If there is a diff erence,
adjust modulating gas valve linkage. Adjust for proper combustion throughout range.
Gas pressure switch
setting is improper
If above two items are proper, check the pressure that the high gas pressure switch is sensing by way of a tee
installed in the line. Hold unit at low fi re and check pressure. Setting on switch should be 10% over pressure read. Call
Fulton if you have any questions.
Gas regulator has
failed open
This is highly unlikely. Regulators will usually fail safe in the closed position. The gas regulator can be checked by
checking upstream pressure and comparing to downstream pressure. Make sure that the upstream pressure is not
above the rating of the regulator. Make sure that the downstream pressure does not exceed the range of the spring.
If regulator has failed, replace, reset input and adjust input throughout the range.
TABLE 10-K - LOW GAS PRESSURE SWITCH TROUBLESHOOTING
Problem Potential Remedy
Gas pressure setting
on the main regulator
is too low
At high fi re, the modulating gas valve is full open resulting in the least amount of back pressure in the gas train. With
unit running at high fi re, check net last elbow gas pressure and compare to factory test fi re sheet. Net gas pressure
is running gas pressure minus purge pressure. Make sure net pressure reading is within .2” w.c. of factory reading. If
there is a diff erence, adjust main regulator. Adjust for proper combustion throughout range.
Gas orifi ce plate is
damaged
If the orifi ce plate is damaged, it may be holding back less gas creating a lower pressure on the sensing switch. Pull
burner and inspect gas orifi ce plate. Plate should in no way be warped or degraded. If it is, replace. After reinstallation,
recheck input and adjust combustion throughout range.
Gas regulator has
failed closed
Regulators will usually fail safe in the closed position. The gas regulator can be checked by checking upstream
pressure and comparing to downstream pressure. Make sure that the upstream pressure is not above the rating of
the regulator. If regulator has failed, replace, reset input and adjust input throughout the range.
TABLE 10-L - LOW OIL PRESSURE SWITCH TROUBLESHOOTING
Problem Potential Remedy
Fuel oil pump may
have lost its prime
An air bubble in the pump will result in a momentary loss of prime that will be enough to cause the Low Oil Pressure
Switch to trip. Ensure that oil pump is primed properly and all connections are tight. Check the pump seal. A blown
seal will allow air in the pump housing.
Fuel oil pump motor
may have failed
Check the pump motor for proper voltage. If voltage is proper but motor does not turn, replace or rebuild motor. If
there is no voltage, check motor starter for input signal and incoming 3-phase power.
Fuel oil pump coupling
may have failed
A failed coupling will result in the pump not turning. Check coupling. Replace if necessary..