925 Control Board Fault Codes - Munchkin Gas-Fired Hot Water Boiler Manual

GAS-FIRED BOILER
PART 14: TROUBLESHOOTING
Table 14-2: 925 Control Board FAULT Codes
Code Description
High Limit Exceeded.
F00
Vent Temperature Limit Exceeded.
F01
Interrupted or Shorted
F02
Supply (Outlet) Thermister.
Interrupted or Shorted
F03
Return (Inlet) Thermister.
Supply (Outlet)
F05
Temperature exceeds 230°F.
Return (Inlet) Temperature
F06
Exceeded 230°F.
No flame detected – The boiler will
make three attempts at ignition
before the control goes into this
F09
lockout condition. *See spark
electrode detail.
Loss of Flame Signal – The boiler
will relight 4 times before the control
F10
goes into this lockout condition.
False Flame Signal – The boiler will
lock out if it senses a flame signal
F11
when there should be none present.
Combustion Fan Speed Low – The
boiler will lock out if it senses that
the fan speed is less than 70% of
F13
expected rate for more than 60
seconds.
Combustion Fan Speed High – The
boiler will lock out if the fan speed is
F14
more than 130% of expected rate for
more than 60 seconds.
Gas Valve Error
F18
Supply voltage frequency out of range. (92-132 VAC 60 Hz)
F19
Watchdog
F30
Parameter Memory
F31
Parameter Memory Write Error
F32
Programming Error
F33
Parameters Programmed
PP
Internal processor error, due to incoming voltage problems. (92-132 VAC 60 Hz). May also occur if neutral wire has been broken or damaged.
Nc
Internal error
F
(CONTINUED)
1. Check circulation pump operation
2. Assure that there is adequate flow through the boiler by accessing the status menu and assuring that there is less than a 50°F rise from the
return thermister to the supply thermister.
3. Check thermister reading on supply thermister. Replace switch if faulty.
4. If this is a new installation, disconnect the two light grey wires from the zone control, and twist the wires together. Depress the S4 reset
button. If the fault clears, the problem is outside the boiler
5. If this is an existing installation with glycol in it, check the condition of the water pressure switch. It may be necessary to jump out the water
pressure switch (temporarily only, as a trouble shooting aid) The 24 VAC signal, may have grounded through the glycol if the water pressure
switch is leaking.
1. Push the red reset button on the switch.
2. Check the flue temperature during operation using a combustion analyzer.
3. Replace the vent limit switch if faulty.
4. Verify the combustion drain if clear and draining properly.
5. Visually inspect the target wall to see if it is intact. If not intact replace target wall.
1. Check the electrical connection to the thermister on the outlet manifold. Verify 5 VDC by checking in Molex connector. Verify thermister
values by referencing chart in this manual.
2. Replace thermister if necessary.
1. Check the electrical connection to the thermister on the inlet manifold. Verify 5 VDC by checking in Molex connector. Verify thermister
values by referencing chart in this manual.
2. Replace thermister if necessary.
1. Check circulation pump operation.
2. Assure that there is adequate flow through the boiler by accessing the status menu and assuring that there is less than a 50°F rise from the
return thermister to the supply thermister.
1. Check circulation pump operation.
2. Assure that there is adequate flow through the boiler by accessing the status menu and assuring that there is less than a 50°F rise from the
return thermister to the supply thermister.
3. Check direction of flow on boiler circulator. (See Piping Details in this manual.)
1. Watch the igniter through the observation window provided.
2. If there is no spark, check the spark electrode for the proper ¼" gap. Use 2 quarters together as a gauge to hold ignitor against to check
gap distance.
3. Remove any corrosion from the spark electrode and flame rectifier probe.
4. If there is a spark but no flame, check the gas supply to the boiler.
5. If there is a flame, check the flame sensor.
6. Check any flue blockage or condensate blocks.
1. Monitor the gas pressure to the unit while in operation.
2. Assure that the flame is stable when lit.
3. Check to see if the green light on the display module is out while the boiler is running.
4. If the green light doesn't come on or goes off during operation check the flame signal on the status menu.
5. If the signal reads less than 1 microampere, clean the flame rectifier probe.
6. If the flame rectifier probe continues to read low, replace it.
7. Check the stability of the flame rectification signal. If the signal is unstable, you may need to replace the burner gasket.
1. Turn the gas off to the unit at the service valve.
2. If the flame signal is still present replace the igniter.
3. If the flame signal is not present after turning off the gas supply, check the gas valve electrical connection.
4. If there is no power to the gas valve, remove the valve and check for obstruction in the valve seat or replace the gas valve.
5. Turn the gas on at the service valve after corrective action is taken.
6. Check for condensate back up. Condensate back up can damage the refractory wall, and if the wall falls against the rectifier probe, it may
conduct the signal to ground, giving a false reading.
1. Check the combustion air fan wiring.
1a. Check the quality of the 24 VAC signal by measuring from any connected safety to ground. A low voltage situation may cause a "false"
error code
2. Replace the combustion air fan.
3. Replace the control board.
1. Check the combustion air fan wiring.
2. Replace the combustion air fan.
3. Replace the control board.
1. Make sure the connector is correctly connected to the gas valve.
2. Check the electrical wiring from the valve to the control board.
2a. Voltage readings will be from 18-22 VDC on the outlet of the gas valve plug from any pin to ground, the connector must remain in contact
with the pins.
2b. On the 399M only, check the 24 VAC relay block.
3. Replace the low voltage wiring harness assembly.
4. Replace control board.
Call factory for further assistance. Watchdog
Call factory for further assistance. Parameter memory error, reprogramming needed
Call factory for further assistance. Parameter memory write error
Call factory for further assistance. Parameter memory error, reprogramming needed
Press S4 reset
Boiler Manual
Remedy
60