Munchkin MUNCHKIN HIGH EFFICIENCY HEATER with the "925" Controller Control Board Error Codes

				TROUBLESHOOTING
Table 7-1: 925 Control Board Error Codes
Code		Description		Remedy
			1.	Check circulation pump operation
		High Limit Exceeded.	2.	Assure that there is adequate flow through the boiler by accessing the
	F00			status menu and assuring that there is less than a 50°F rise from the
			3.	return thermister to the supply thermister.
				Check thermister reading on supply thermister. Replace switch if faulty.
			1.	Push the red reset button on the switch.
			2.	Check the flue temperature during operation using a combustion
	F01	Vent Temperature Limit Exceeded.
				analyzer.
			3.
				Replace the switch if faulty.
		Interrupted or Shorted	1.	Check the electrical connection to the thermister on the outlet manifold.
	F02
		Supply (Outlet) Thermister.	2.	Replace thermister if necessary.
		Interrupted or Shorted	1.	Check the electrical connection to the thermister on the inlet manifold.
	F03
		Return (Inlet) Thermister.	2.	Replace thermister if necessary.
		Supply (Outlet)	1.	Check circulation pump operation.
			2.	Assure that there is adequate flow through the boiler by accessing the
	F05
		Temperature exceeds 230°F.		status menu and assuring that there is less than a 50°F rise from the
				return thermister to the supply thermister.
		Return (Inlet) Temperature	1.	Check circulation pump operation.
			2.	Assure that there is adequate flow through the boiler by accessing the
	F06
		Exceeded 230°F.		status menu and assuring that there is less than a 50°F rise from the
				return thermister to the supply thermister.
		No flame detected – The boiler will	1. Watch the igniter through the observation window provided.
			2.	If there is no spark, check the spark electrode for the proper ¼” gap.
		make three attempts at ignition	3.	Remove any corrosion from the spark electrod and flame rectifier probe.
	F09
		before the control goes into this	4.	If there is a spark but no flame, check the gas supply to the boiler.
		lockout condition.	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.
		Loss of Flame Signal – The boiler	3.	Check to see if the green light on the display module is out while the
				boiler is running.
		will relight 4 times before the
	F10		4.	If the green light doesn’t come on or goes off during operation check
		control goes into this lockout
				the flame signal on the status menu.
		condition.	5.
				If the signal reads less than 1 microampere, clean the flame rectifier
			6.	probe.
				If the flame rectifier probe continues to read low, replace it.
			1. Turn the gas off to the unit at the service valve.
		False Flame Signal – The boiler will	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
	F11	lock out if it senses a flame signal		the gas valve electrical connection.
		when there should be none present.	4. If there is no power to the gas valve, remove the valve and check for
			5.	obstruction in the valve seat or replace the gas valve.
				Turn the gas on at the service valve after corrective action is taken.
		Combustion Fan Speed Low – The
		boiler will lock out if it senses that	1.	Check the combustion air fan wiring.
	F13	the fan speed is less than 70% of	2.	Replace the combustion air fan.
		expected rate for more than 60	3.	Replace the control board.
		seconds.
		Combustion Fan Speed High – The	1.	Check the combustion air fan wiring.
		boiler will lock out if the fan speed is
	F14
		more than 130% of expected rate	2.	Replace the combustion air fan.
		for more than 60 seconds.	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.
	F18	Gas Valve Error
			3.	Replace the low voltage wiring harness assembly.
			4.	Replace control board.
		Watchdog	Call factory for further assistance.
	F30
		Parameter Memory	Call factory for further assistance.
	F31
		Parameter Memory Write Error	Call factory for further assistance.
	F32
		Programming Error	Call factory for further assistance.
	F33

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