Williams 2903512 Furnace User Manual


 
Point 13 (TR)
No inlet voltage (120 V).
Check 5 pole connector and control box.
If everything is okay, replace the connector.
No outlet voltage (24 V) during ignition.
Check wiring and connections.
If everything is okay, replace the transformer.
Point 14 (EV1)
Valve closed during ignition (Z2 down).
Check wiring, connections and voltage.
If everything is okay, replace the gas valve.
Point 15 (RP7)
No spark during ignition.
Check electrode, wiring and connections.
If everything is okay, replace the flame control box.
Point 16 (RP8)
No flame sensing.
Check flame sensor, wiring and connections.
Check gas pressure and exhaust flue pipe.
If everything is okay, replace the flame control box.
Point 17 (EV2)
No voltage on EV2 with Z2 up.
Check wiring and connections.
If everything is okay, replace the switch.
Valve closed with voltage with Z2 up.
Check wiring, connections and voltage.
If everything is okay, replace the gas valve.
Starting Sequence (Gas)
1. Check and clean exhausted flue pipes;
2. Check and clean air blower and fan motor;
3. Check and clean burner and combustion chamber;
4. Check and clean gas nozzle;
5. Check gas type;
6. Check supply gas line pressure (see the manual);
7. Check gas losses;
8. Set burner gas pressure (see the manual).
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