Munchkin Boiler troubleshooting

CodeDescriptionCorrective Action
E00High Limit Exceeded1. 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. Replace switch if faulty.
E13Combustion Fan Speed Low. The boiler combustion air fan speed less than 70% of expected.1. Check the combustion air fan wiring.
2. Replace the combustion air fan.
3. Replace the control board.
E14Combustion Fan Speed High. The boiler combustion air fan speed is more than 130% of expected.1. Check the combustion air fan wiring.
2. Replace the combustion air fan.
3. Replace the control board.
ProWaterPressure Switch Open1. Assure that the system pressure is above 10 psig.
2. Check for leaks in the system piping.
FLUBlocked Vent Pressure Switch Open1. Assure that the vent is not blocked
2. Check the switch operation by applying a jumper. (If the switch is not functioning properly, replace it.)
F00High Limit Exceeded.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.
F01Vent Temperature Limit Exceeded.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.
F02Interrupted or Shorted Supply (Outlet) Thermister.1. Check the electrical connection to the thermister on the outlet manifold. Verify 5 VDC by checking in Molex connector. Verify therm ster values by referencing chart in this manual.
2. Replace thermister if necessary.
F03Interrupted or Shorted Return (Inlet) Thermister.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.
F05Supply (Outlet) Temperature exceeds 230°F.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.
F06Return (Inlet) Temperature Exceeded 230°F.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.)
F09No flame detected The boiler will make three attempts at ignition before the control goes into this lockout condition. *See spark electrode detail.1. Watch the igniter through the observation window provided.
2. If there is no spark, check the spark electrode for the proper Vi" 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.
F10Loss of Flame Signal The boiler will relight 4 times before the control goes into this lockout condition.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.
F11False Flame Signal The boiler will lock out if it senses a flame signal when there should be none present.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.
F13Combustion Fan Speed Low The boiler will lock out if it senses that the fan speed is less than 70% of expected rate for more than 60 seconds.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.
F14Combustion Fan Speed High The boiler will lock out if the fan speed is more than 130% of expected rate for more than 60 seconds.1. Check the combustion air fan wiring.
2. Replace the combustion air fan.
3. Replace the control board.
F18Gas Valve Error1. 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.
F30WatchdogCall factory for further assistance. Watchdog
F31Parameter MemoryCall factory for further assistance. Parameter memory error, reprogramming needed
F32Parameter Memory Write ErrorCall factory for further assistance. Parameter memory write error
F33Programming ErrorCall factory for further assistance. Parameter memory error, reprogramming needed
PPParameters ProgrammedPress S4 reset
FInternal error

Error codes and troubleshooting