Troubleshooting Chart - Williams 2001622A Owner's Manual

Troubleshooting
SYMPTOM
1. Pilot will not stay lit
after following
lighting instructions.
2. Pilot burning - no
gas to the main
burner.
3. Burner comes "ON"
but goes OFF
before blower turns
ON.
4. Heater not
producing sufficient
heat.
POSSIBLE CAUSE
A. Generator producing
insufficient millivolts.
B. Loose or dirty
generator
connections at gas
valve.
C. Generator defective.
D. Grounded thermostat
wire.
E. Defective valve.
A. Thermostat not turned
to a position calling
for heat.
B. Plugged burner
orifice.
C. Improperly wired or
broken thermostat
wires.
Defective thermostat.
D. Pilot generator may
not be generating
sufficient millivoltage
to open valve.
E. Defective valve.
A. Thermostat location.
B. Defective thermostat.
A. Heater may be too
small for space being
heated.
B. Heater not burning at
full rate.
Check pilot flame – it must impinge on the generator from 1/4 to 3/8-inches .
Be sure the thermocouple is fully inserted in its bracket.
Clean and/or tighten the connections at the valve.
Check the generator with millivolt meter. Take reading at the generator
terminals of the valve with the valve placed in "Pilot" position. Disconnect the
thermostat wires. The millivolt reading should be 450 millivolts or more.
Remove the thermostat wires from the valve terminals.
If the pilot now stays lit, trace the thermostat wiring circuit for a ground. May
be grounded to heater, gas supply, nails or staples.
Replace the gas valve after above is verified.
Set the thermostat to a position calling for heat.
Clean or replace.
Check the connections at valve terminals. If valve operates, check the
thermostat wires.
See 1A and 1C above.
Replace.
Check the thermostat location. It should not be in the path of warm air
discharge from heater, near a lamp, or above a T.V. or stereo.
Check the thermostat calibration or replace.
Check heat sizing calculations.
Check for low gas pressure at gas valve. It should be 4 inches W.C. for
Natural Gas; 10.5 inches W.C. for L.P.G. Check for blocked burner orifice.
CORRECTIVE ACTION