Whirlpool EDP/EDN - Manual (Page 22)

Page 22 LAARS HEATING SYSTEMS
4. 10 seconds after establishing combustion and
proof of flame ( via the flame rod signal to
ground ), the ignitor will be de-energized and
the burner will modulate to high fire for
maximum output.
5. The [MC] should indicate a rapid rise in
temperature to 150º F (1-2 min. duration).
During this period the thermostatic union at the
flow outlet is closed and the boiler is operating
in the internal recirculation mode. [Service note:
If the temperature rise is not rapid the union
thermostat may be defective and must be
replaced].
6. At 150° F the thermostat will allow increased
flow to the system and a gradual rise in
temperature will be indicated until the
temperature approaches the setpoint temperature
of 180ºF. The firing rate will start to modulate
downward until its cutoff limit is reached or the
call for heat is satisfied.
The EBP modulating combination boiler will
start from any of three input signals: (a)T-T closure
for space heating. (b)A demand for domestic hot
water, signaled by water flow activation of the water
flow switch. (c)A call for heat from the minimum
tank temperature sensor at 158°F (tank charge mode).
In tank charge mode the red LED located below the
green LED on the PCB will be lit. In modes (b) and
(c) which are priority modes, the internal anti-
condensing valve will be closed. On a T-T call for
heat the valve will remain closed until the priority
modes are satisfied.
[Service note: as with the thermostatic union in
the EDP/EDN models, the anti-condensing valve
prevents condensation on the combustion chamber
coil and must be in the closed position when the coil
inlet (F6) indicates a temperature below 130°F].
8B. Trouble Shooting - Fault Codes
The Endurance boiler is controlled by a Pactrol
integrated boiler control (PCB) which provides eight
fault codes with eight memories. To obtain fault
messages press-in on the message center fault button
until the first fault code (FLI) is displayed.
If a thermistor error occurs, it will appear on the
LED upon power-up. The memory does not need to
be accessed. Memory fault codes are for error
history only. All thermistor faults will show as “F”
codes on the LED, and will never cause the LED to
read “LO”. (Note that the unit is shipped with error
codes already in memory, and an error code that is
shown in memory upon start-up of a new unit is from
manufacturing testing.)
The last recorded fault will appear e.g. F-4 (flow
thermister faulty - open or shorted). The control will
then sequence through all eight memories, indicating
alternately the fault number and the fault code (FL1,
F-?; FL2, F=?; …, FL8, F=?). The fault number in
fault code FL1 is the most recent fault.
8B-1. Fault Code Identification
The following eight fault codes may be observed:
F-
Error corrected, control in auto reset time
period (10 seconds)
F-0 No fault has occurred
F-1 Error occurred reading fault logic of main
control
F-2 Over heat thermostat has operated
(open circuit)
F-3 Fan fault
F-4 Flow temperature sensor faulty
(open or short circuited)
F-5 Tank temperature sensor faulty
(open or short circuited) (Combi unit only)
F-6 Return temperature sensor faulty
(open or short circuited)
8B-2. Fault Correction (see also Fault
Trees in this Section)
F-1 Switch off boiler and restart. If F-1 repeats,
replace PCB
F-2 The overheat thermostat (safety limit)
opens at 230°F. Observe boiler operation if
the boiler shuts off before the
indicates 225°F (107°C) replace safety
limit. If the temperature rises rapidly and
the safety limit operates, the internal pump
is not operating. Refer to the wiring
diagrams and check for voltage (120V)
across the terminals on the PCB marked PMP.
a.
If there is no voltage, and the PCB
display does not indicate on or off,
replace PCB
b. If there is voltage, the pump or wiring
is defective.
F-3 Attempt to start the boiler. Check
combustion air blower operation. If F-3 is
indicated again, replace blower.
F-4 Check for damaged wiring or poor
connection at sensor plug. If they are OK
disconnect the sensor plug and check the
resistance across the sensor terminals. The
resistance of a good sensor is 10,000 ohms
@ 77°F (25°C). Replace sensor if
resistance is less than 500 or more than
20,000 ohms.
F-5 Correct in the same manner as F-4.
F-6 Correct in the same manner as F-4.
8B-3. Resolving Lockouts (LO)
(The memory does not need to be accessed.
Memory fault codes are for error history only. All
thermistor faults will show as “F” codes on the
LED, and will never cause the LED to read “LO”.
There are many causes for lockouts. The five
most common causes are: (1) poor combustion,