Specifications

Diagnostics
GAND-SVX01B-EN 39
U. No Spark. 1. Thermostat not calling for heat. 1. Close thermostat contacts.
2. No low voltage. 2. Check for 24V across 24V terminals of S8600.
3. Spark gap closed or too wide. 3. Set gap to 0.1.
4. Broken or cracked ceramic on
spark electrode.
4. Replace pilot assembly.
V. Spark present but pilot does not
light.
1. Loose S8600 connections. 1. Check all connections, term. PV feeds 24V to pilot valve.
2. Improper gas pressure. 2. Check pressure—pressure that is either too high or too low
may cause a problem.
3. Is spark in pilot gas stream? 3. Spark should arc from electrode.
4. No pilot gas — do not use match to
test - presence of gas is easily
detected by the odor.
4. Check pilot line for kinks. Ensure there are no drafts.
W. Pilot lights — Main valve does not
energize.
1. Loose S8600 connections. 1. Check connections-term. MV feeds main valve.
2. Cracked or broken sensor
ceramic.
2. Replace pilot assembly.
3. Check sensor/spark lead for
continuity.
3. Replace if needed.
4. Measure 24 volts from term. MV to
term. MV/PV.
4. If present, replace main valve; if not, replace S8600 Igniter.
X. Hi-Limit switch tripping 1. Vertical run of flue is too short. 1. Lengthen vertical run of flue pipe (see “Installation:
Venting,” p. 18).
2. Unit is overfiring. 2. Burner orifice may be too large: verify/replace if required.
3. Air flow too low. 3. Increase air flow; check fan size. Check for proper voltage.
4. Defective switch. 4. Replace.
Y. Noisy power venter. 1. Power venter wheel loose. 1. Replace or tighten.
2. Power venter wheel dirty. 2. Clean power venter wheel.
3. Power venter wheel rubbing
housing.
3. Realign power venter wheel.
4. Bearings are dry. 4. Oil bearings on power venter motor. (Refer to label on
motor).
Z. Power venter will not run. 1. Loose wiring. 1. Check and tighten all wiring connections per diagrams.
Thermostat wires tagged “W” and “G” must be connected
together (unless special thermostats are used; if so see
thermostat wiring diagram, “Electrical Connections,” p. 24).
2. Defective motor overload
protector or defective motor.
2. Replace motor.
3. Defective power venter relay. 3. Check for 24V across 1 and 3 terminals on fan relay. If 24V
is present, jumper terminals numbered 2 and 4. If motor
runs, the relay is defective and must be replaced. If 24V is
not present, check wiring per diagrams.
AA. Power venter motor turns on and
off while burner is operating.
1. Fan relay heater element
improperly wired.
1. Be sure relay heater terminals are connected per diagrams.
2. Defective venter relay switch. 2. Replace venter relay.
3. Motor overload protector cycling
on and off.
3. Check motor amps against motor name plate rating, check
voltage; replace power venter motor if defective.
4. Motor not properly oiled. 4. Refer to label on motor.
AB. Power venter motor will not stop. 1. Improperly wired venter relay. 1. Check all wiring.
2. Main burner not lighting while
thermostat calls for heat.
2. Refer to H and N symptoms.
3. Defective venter relay. 3. Replace venter relay.
Table 7. Troubleshooting guide (continued)
Symptoms Possible Cause(s) Corrective Action