Troubleshooting - Williams 1753012 Owner's Manual

Troubleshooting

SYMPTOM
1. Furnace operates,
but turns "OFF"
before room
temperature is
attained.
2. Furnace not
producing sufficient
heat.
3. Furnace operates,
but will not shut
"OFF" when room
temperature is
attained.
4. Abnormal
operation.
5. Noisy Blower.
6. A1 Error Code.
7. A2 Error Code.
8. A5 Error Code.
9. A7 Error Code.
10. A8 Error Code.
11. A9 Error Code.
12. Gas valve is not
modulating.
POSSIBLE CAUSE
A. External thermostat location.
B. Defective external thermostat.
A. Furnace may be too small for space
being heated.
B. Furnace not burning at full rate.
A. External thermostat wiring defective.
B. External thermostat location.
C. Defective external thermostat.
D. Defective valve.
A. Expansion noise ticking.
A. Housing rattling.
B. Blower dirty.
C. Blower wheel bent.
Flame loss or flame not present lockout.
Condensing water High level reached.
Hi Limit Lockout.
Air flow not sufficient.
Room probe too high.
Room probe failure.
Faulty wiring or JP5 jumper on control
board.
CORRECTIVE ACTION
Check the thermostat location. It should not be
in the path of warm air discharge from the
furnace, near a lamp or above a T.V. or stereo
set.
Check the thermostat calibration or replace.
Check heat calculations.
Check for low gas pressure. Check the burner
orifice.
Thermostat lead wires
together, by a nail or staple. Check by
removing thermostat leads from the valve
terminals.
Check the thermostat location. If on an outside
wall or there is a hole in the wall behind the
thermostat causing cold air to contact the
thermostat. Relocate the thermostat.
Check the thermostat calibration or replace.
Replace the valve.
Casing may be distorted by being fastened to
an uneven wall. Vent tube and air inlet tube
may be in a bind with a vent cap assembly. Be
sure the hole through the wall is correct and
parts fit without binding.
Tighten blower housing screws.
Clean blower wheel.
Straighten or replace.
Check gas supply. Check flame sensor
connection; check
connection. Replace sensor or hot surface
igniter if necessary.
Check condensate trap hoses for blockage.
Check circulation fan motor connections and
replace motor if necessary; check hi limit
switch connections and replace switch if
necessary; check inducer fan hi limit switch
connections.
Check air pressure sensor wiring connections;
check air pressure sensor hose connections
and replace sensor if necessary; check for
blocked exhaust.
Check thermistor asy.
replace if necessary.
Check thermistor asy.
replace if necessary.
Check harness connections and replace if
faulty; JP5 jumper should not be present on
NG model; JP5 jumper should be present on
LP model.
may be shorted
hot surface igniter
Connections and
Connections and