A.O. Smith GDVH, XDVS Troubleshooting, Problem, Possible Malfunction, Service To Be Performed

TROUBLESHOOTING

Please check guidelines below. For your safety, water heater service should be performed only by a qualified service technician. Read the GENERAL SAFETY INFORMATION section first.

PROBLEM	POSSIBLE MALFUNCTION			SERVICE TO BE PERFORMED	POSSIBLE SOLUTION
NO HOT WATER	1)	No pilot
		A.	No gas to pilot	Check gas supply	Turn on, check pressure
				Check gas valve	Turn on or replace if needed
				Check pilot orifice for obstruction	Clean with air or replace
				Check pilot tube for kink or leaks	Replace pilot tube
		B.	Pilot will not stay lit	Check gas pressure
				Check thermostat MV drop-out voltage
				Check thermocouple connection and	Tighten if loose, replace
				MV output	as necessary
				Check thermocouple placement in pilot flame	3/8- should be in flame
				Check pilot for proper flame	Change pilot orifice
				Check ECO operation	Replace gas valve
				Check for air in pilot tube	Bleed as necessary
		C.	Pilot blows out	Leaking joints	Check all vent joints for proper seal.
					Make sure to check inner and outer
					pipe and check rear air tube seals.
					Refer to installation manual.
				Check for proper vent cap	Install A. O. Smith provided vent cap
				Check for bent, missing, or mislocated
				pilot shield (natural gas units only)	Replace or reposition
				Check outer door seal	Replace gasket if missing
					Tighten screws if loose
					Install gasket properly if misinstalled
NOT ENOUGH	1)	Incorrect burner orifice		Check orifice size	Replace with correct size
HOT WATER	2)	No gas to main burner		Check gas supply	Correct as needed
				Check thermostat operation	Replace as needed
	3)	Heater too small		Confirm sizing requirements	Replace with larger heater, add
					another heater, or decrease
					water usage.
YELLOW FLAMES	1)	Excessive or low gas		Check gas pressure
OR SOOT		pressure
	2)	Combustion air restricted		Check vent for restrictions	Correct as necessary
				Check venting for extra piping	Re-install as recommended in
					the installation manual
CONDENSATION	1)	Water on floor under heater		See page 21 “CONDENSATION”
BURNER WILL	1)	Low gas pressure		Check gas supply pressure
NOT STAY LIT				Check thermostat operation
	2)	Downdraft or		Check for proper vent cap	Install proper vent cap
		backdraft condition		Check location of heater	Re-install in correct location
				Check for proper vent sealing	Reseal venting
				Check top and/or bottom air supply	Seal as necessary
				box for air leaks
				Check outer door seal	Replace gasket, tighten screws
					or re-install gasket as necessary

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