Troubleshooting - Williams 2903512 Installation Instructions And Owner's Manual

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, wirings and
connections.
Point 2 (M9).
Fuse damaged.
Check the electrical supply line and replace the
fuse.
SUMMER MODE
STEP 2
3. Check Z1 (Reset and 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 block.
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 wirings and connections. If they are OK replace the
switch.

Troubleshooting

20
V = 120 V
Max Min