Boiler Control Instruction & Operation Manual
Page
48
of
68
Trouble- Shooting
General Issues
WARNING
Electrical Shock Hazard. Turn off power to boiler before working on wiring. This boiler must only be
serviced by skilled and experienced service technician.
Troubleshooting when
“Help” icon
NOT
flashing;
Indication
Condition
Possible Cause
Boiler not responding to call for
heat,
“Status” and “Priority” show
“
Standby
”.
Demand Not
Detected
Boiler is not seeing Enable/Disable of Domestic Demand
Input. Check wiring loose connection, miswiring. If Domestic
Demand is expected check that DHW Demand/ Modulation
is selected properly.
Boiler not responding to a call for
heat,
“Status” shows “Standby”
and
“Priority” shows Central Heat
or Domestic Hot Water.
Pumps
Running and
Boiler is not
Running
Boiler is not firing, temperature is greater than setpoint. Select
display Help icon and review Limit String Status.
Boiler Running but System
or Boiler Circulator is not running
Pumps Not
Running
Check wiring for loose connection, miswiring.
When there is a Domestic Hot Water Heat Request the
System or Boiler pumps will be forced
“off” when there “Run
Pump f
or” parameter is set to “Central heat, off DHW
deman
d” or “Central Heat, Optional Priority”. This has been
set to allow all of the heat to be provided for fast indirect
water heater recovery. After
“priority protection” time or the
end of the Domestic Hot Water Heat Request the system
and boiler pumps will be free to run.
Display Completely Dark
Fan off, LWCO lights off, no green
power light on Control
No 120Vac
Power
at Boiler
Check breaker and wiring between breaker and boiler.
Blown high voltage fuse or breaker tripped.
Display Completely Dark,
Fan running
No 24Vac
Power to
Control
No 24 Vdc to
Display
Loose 120Vac connection wiring between boiler J-Box and
transformer or 24 Vdc power supply.
Loose 24 Vac wiring connection between transformer and
Control.
Blown low voltage fuse or transformer blown.
Bad transformer or bad 24 Vdc power supply.
Blinking Green power light on
Control
Control
Fault
The green light is connected to internal power supply. The power
supply is repeatedly starting and stopping (not normal) making
the light flash. The microprocessors are not running. Try
disconnecting all terminals except 24VAC to power the Control.
The green light should be steady. If it is not, then the control is
defective. If steady, start plugging in all the connectors while
watching the green light. When faulty wiring reconnected, green
light will begin to flash.
