Williams 2903512 - Manual (Page 20)

Troubleshooting
Starting Sequence (Electrical)
Step 1
1. Check L1 – L2 (Supply 120 V, 60 Hz)
2. Check M9 (Main fuse)
Troubleshooting Step 1
Point 1 (L1-L2)
No voltage (120 V).
Check the electrical supply line, wiring and
connections.
Point 2 (M9)
Fuse damaged.
Check the electrical supply line and replace the
fuse.
Summer Mode
Step 2
3. Check Z1 (Reset summer/winter switch). The
switch is closed if there is no ignition block.
4. Check Z2 (Hi-Lo flame and fan speed switch)
Button down - Minimum velocity
Button up – Maximum velocity
Troubleshooting Step 2
Point 3 (Z1)
Z1 is open and no ignition.
Check wirings and connections. If everything is okay,
replace the switch.
Point 4 (Z2)
Z2 is down but the fan motor runs at the maximum
velocity (120 V).
Z2 is up but the fan motor runs at the minimum
velocity (<120 V).
Check wiring and connections. If they are okay,
replace the switch.
Winter Mode
Step 3
5. Check Z1 (Reset summer/winter
switch).
Button up – winter mode.
6. Check Z3 (Manual-automatic switch).
Button up – manual mode
Button down – automatic mode.
7. Check M2 (Fan thermostat).
The thermostat is closed only when its
temperature is higher than 104 °F.
19