Bradford-White Corp Modulating Boiler, BNTH continued next page, Code#, Problem, Probable Cause

Page 50			BRADFORD WHITE CORP.
CODE#	PROBLEM	PROBABLE CAUSE	SOLUTION
		COMMON LOCKOUT CODES
27	Internal error	Flame rod to ground	Check wiring / probe grounded, dirty probe
47	Flame rod to ground leakage	Faulty flame detector	Clean or replace flame detector
49	24VAC voltage low/high	Faulty transformer	Check/correct supply line voltage; replace faulty
			transformer
52	Motor tachometer fault	Faulty fan / fan wiring	Check fan harness wiring for continuity; replace faulty
		fan circuit
53	AC inputs phase reversed		Reverse 24V hot/neutral - use common ground
61	Anti short cycle	Call for heat will be held	Change ASC timer setting
		until timer resets
62	Fan speed not proved	Dirty / defective fan	Clean or replace fan; check wiring
63	LCI off	Safety chain interrupt	Check flow switch, aux high limit, LWCO, gas
			pressure switches, condensate level and correct
			problem
69	Outlet high limit	High limit tripped	Determine cause: low/no flow, valves closed, settings
			and correct
79	Outlet high limit		Check pump, time delay, valves closed, etc. and
80	DHW high limit	High limit reached
			correct overtemp
81	Delta T inlet/outlet limit
82	Stack limit	High limit reached	Could be caused by high ambient temperature, or
			high return water temperature
88	Outlet T-rise limit	High limit reached	Diagnose / repair cause of high temperature
90	Heat exchanger high limit
91	Inlet sensor fault
92	Outlet sensor fault	Faulty sensor or wiring	Check wiring / replace sensor; condition can be
93	DHW sensor fault
			caused by short
95	Stack sensor fault
96	OAT temperature sensor fault	Faulty outdoor air	Check wiring and sensor for short; replace sensor
	temperature sensor	is open or shorted
105	Flame detected	Flame exists at burner	Clean burner of soot or other debris that could
	out of sequence	when it should not be	maintain flame
106	Flame lost in MFEP	Unstable flame during
107	Flame lost early in Run	lighting / flame proving	Check venting, gas supply pressure, burner, fan, etc.
		sequence
108	Flame lost in Run
109	Ignition failed	Problem with ignitor, or	Check / replace ignitor, wiring; check for shorting
		other ignition-related device	in ignitor cable
113	Flame circuit timeout	Flame not established	Check all combustion components; purge gas;
		within expected time limit	check ignition source

122Lightoff rate proving failed

123Purge rate proving failed

128	Fan speed failed / prepurge	Fan did not reach	Check fan wiring; replace fan
129	Fan speed failed / preignition	expected RPM
130	Fan speed failed / ignition
131	Fan movement detected	Fan should not be moving	Check for common venting problems or otherwise
	during standby	when not powered	forced air
132	Fan speed failed during run	Fan lost or gained speed	Fan overheating or otherwise failing; check cable;
		during run sequence away	replace fan
		from control spec
137	ILK failed to close	No power at interlock ILK	Check J5 pin 1 for power - if no power, confirm
			safeties are closed

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