1307SDH_RDH--EN,
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TROUBLESHOOTING
General troubleshooting
13
PROBLEM
PROBABLE CAUSE
REMEDY
1. No power to unit.
1. Turn on power, check supply fuses or circuit breaker.
2. No power to venter motor.
2. Check connections at burner relay and/or venter motor terminals.
3. Integrated burner relay defective.
3. Replace burner relay.
4. Defective venter motor.
4. Replace venter motor.
5. Fluse blown (F3.1).
5. Replace fuse.
6. Fuse burner relay blown.
6. Replace fuse.
7. LC3 open.
7 a) Reset LC3.
b) Replace LC3.
c) Check if there is obstruction at the fan side.
8. Unit in lock-out.
8. Push on reset button.
9.Room thermostat open.
9.Set thermostat above room temperature.
1. Main valve not operating.
1. a) Check voltage on valve during ignition period.
b) Check connector on main gas valve.
c) Check connector on burner relay.
d) Replace valve.
2. Air in the gas line.
2. Purge gas line.
3. Gas pressure too high or too low.
3. a) Supply pressure should be 20 mbar for natural gas or 37 mbar for
propane gas.
b) Obstruction in the gas line.
c) Gas line connection diameter too small.
4. No Spark:
4. Check the following :
a) Loose wire connections.
a) Be certain all wire connections are solid.
b) Incorrect spark gap.
b) Maintain spark gap at 3 mm.
c) Spark cable has a short circuit to ground.
c) Replace worn or grounded spark cable.
d) Spark electrode has a short circuit to
d) Replace if ceramic spark electrode is cracked or grounded.
e) Burner relay not grounded.
e) Check burner relay ground wire.
f) Unit not properly grounded.
f) Make certain unit is properly field grounded (earthed) and properly
phased (L1 to hot lead L2 to neutral).
g) Faulty burner relay.
g) If voltage is available to the burner relay and all other causes have
been eliminated, replace burner relay.
5. Combustion air pressure switch
5. First check the following :
not closing upon power to venter.
a) Make sure unit is properly vented.
b) Remove obstructions from vent.
c) Replace faulty tubing to pressure switch.
d) Replace faulty pressure switch.
Burner cycle
on and off
1. Gas pressure too high or too low.
1. Supply pressure should be 15 mbar for natural gas (UK only) or 37
mbar for propane gas.
2. Burner relay not grounded.
2. Check burner relay ground wire connection.
3. Faulty burner relay.
3. If (220/240) volts is available to the burner relay and all other causes
have been eliminated, replace burner relay.
4. Flame sensor grounded.
4. Be certain flame sensor lead is not grounded or insulation or ceramic is
not cracked. Replace as required.
5. Cracked ceramic at sensor.
5. Replace sensor.
6. Incorrect polarity.
6. Check polarity and if necessary reverse line voltage wires to terminal
block connections.
1. Circuit open.
1. Check wiring and connections.
2. Defective fan time delay relay
2. Replace the time delay relay.
3. Defective motor.
3. Replace blower & motor.
Fan or venter
motor turns
on and off
while burner
is operating
1. Motor internal thermal protection device
cycling on and off.
1. Check motor load against motor rating plate. Replace motor if needed.
Venter motor
will not start
fan motor will
not run
Burner will
not light
