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,
