25
Masport F43/F28 Freestanding Gas Heater
POSSIBLE
PROBLEM
CAUSES
CORRECTIVE ACTION
Note:
Before troubleshooting the gas control system, be sure external gas shut off is in the "on" position.
• WARNING •
BEFORE DOING ANY GAS CONTROL SERVICE WORK, REMOVE THE GLASS FRONT.
TROUBLESHOOTING GUIDE
Spark igniter will not
light pilot.
Pilot will not stay lit
after carefully fol-
lowing lighting in-
structions.
Pilot burning, no
gas to burner.
Valve knob is on.
Wall switch is on.
Frequent pilot out-
age problems.
Piezo wire loose
Defective Piezo igniter.
Piezo wire grounding out.
Electrode is grounding out
and/or wrong location.
Defective thermopile.
Defective thermocouple.
Thermopile/thermocouple
grounding out.
Loose thermopile leads.
TP-THTP on valve.
Defective automatic gas
valve.
Valve wire connections are
loose.
Valve wires are defective.
Spill switch has not been re-
set (F/S).
Spill switch is stuck in the
open position. (INS - F/S).
Pilot flame may be too low
or blowing high causing the
pilot safety to drop out.
Two way switch wires may
be grounding out.
Thermopile and/or thermo-
couple may be grounding
out.
•
Check for spark at electrode and pilot. If no spark, disconnect wire
at electrode and put wire to ground and try igniter again. If still no
spark follow Piezo wire to Piezo igniter to see where grounding
may be occurring.
• Bend electrode into pilot so gas may be able to contact spark.
• Check pilot flame, must impinge on thermopile and thermocouple.
• Clean and/or adjust pilot so pilot is enveloped around thermopile
and thermocouple.
• Be sure wire connections at gas valve terminals are tight and ther-
mopile and thermocouple are fully inserted into pilot bracket.
• One of the switch wires may be grounded. May be grounded to
gas appliance or gas supply.
• Check thermopile with millivolt meter. Take reading at thermopile
terminals of valve TP-TPTH. Should read 250 millivolts minimum
while holding valve knob in pilot position with pilot on and wall
switch/two way switch off.
• Replace if lower than specified minimum.
• Turn valve knob to on including pilot. Take reading at TP-TPTH
with on/off switch in the on position. Reading should be 100mv or
greater. If reading is okay and pilot does not hold, replace gas
valve.
• Check two way switch/wall switch for proper connections. Jumper
wire across terminals at two way switch/wall switch. If burner comes
on, replace switch.
• If okay, jumper wire at valve at TH-THTP. If unit turns on, replace
wires and/or check where loose wires are.
• Clean and/or adjust pilot for maximum flame impingement on
thermopile and/or thermocouple.
• Trace wires from valve to two way switch/wall switch for possible
grounding against gas appliance and/or gas supply.
• Trace thermopile wires from valve to thermopile for possible
grounding against gas appliance and/or gas valve.
• Follow same steps for thermocouple.
Note:
For service technicians only. See the Masport Troubleshooting Guide for more detailed information.
TROUBLESHOOTING THE GAS CONTROL SYSTEM
MAINTENANCE
ABNORMAL OPERATION
If the main burner does not light but pilot stays on shut down heater and contact your dealer
If excessive carbon on logs or glass contact your dealer
