S+H Nolting NG-15, Operating Instructions Manual

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8. POSSIBLE MALFUNCTIONS AND THEIR CAUSES :
Malfunction: Cause: Remedy:
WAH does not start No room thermostat connected or
no bridge on the thermostat jack
(Item 20)
Room thermostat incorrectly set
Gas hookup
Connect the room thermostat
or bridge to the thermostat
jack
Check setting
Check
WAH starts, ignition present
but solenoid valve does not
open ………….fault shutdown.
Safety thermostat triggered or is
defective (
Item 15 )
Automatic gas firing unit
defective
(Item 16 )
Reset or replace
Replace
WAH starts, no ignition,
solenoid valve opens,
gas flows in….fault shutdown. Ignition electrode defective
(Item 12)
Ignition gap too large
Ignition cable defective (Item 7)
Automatic gas firing unit
defective
(Item 16 )
Replace
Reduce
Replace
Replace
WAH starts, ignition present,
solenoid valve opens, gas
flows in, is ignited …………
after several seconds fault
shutdown occurs.
Automatic gas firing unit
defective
(Item 16 )
Ionization cable dirty or defective
(
Item 23 )
Ionization electrode dirty or
defective (
Item 17 )
Replace
Clean or replace
Clean or replace
WAH starts, ignition present,
solenoid valve opens, no gas
flows in………fault shutdown. Gas regulator defective (Item 14)
Gas pressure
Nozzle clogged
Solenoid or gas line clogged
(Item 9)
Replace
Check
Clean, replace
Clean by blow-through
WAH occasionally goes to fault. Ionization ignition electrode
(Item 17 )
Ignition
Switch box
Gas pressure
Check
Check
Check for loose contacts
Check