Troubleshooting Guide, Start Up Conditions

TROUBLESHOOTING GUIDE

Start Up Conditions

Thermal Expansion

NOTE: Expansion tanks are pre-charged with a 40 psi air charge. If the inlet water pressure is higher than 40 psi, the expansion tank’s air pressure must be adjusted to match that pressure, but must not be higher than 80 psi.

As water is heated, it expands (thermal expansion). In a closed system, the volume of water will grow. As the volume of water grows, there will be a corresponding increase in water pressure due to thermal expansion. Thermal expansion can cause premature tank failure (leakage). This type of failure is not covered under the limited warranty. Thermal expansion can also cause intermittent temperature-pressure relief valve operation: water discharged from the valve due to excessive pressure build up. The temperature-pressure relief valve is not intended for the constant relief of thermal expansion. This condition is not covered under the limited warranty.

A properly sized thermal expansion tank should be installed on all closed systems to control the harmful effects of thermal expansion. Thermal expansion tanks are available from Sears stores and through the Sears Service Centers. Contact the local plumbing inspector, water supplier and/or the Sears Service Center for assistance in controlling these situations. See Figure 42.

TABLE 5

Thermal Expansion Tank Specifications

	Tank	Dimensions			Pipe
Model	Capacity	in Inches			Fitting
Number	In Gallons	Diameter		Length	On Tank
153.331020	2	8 (203 mm)	12-3/4 (323 mm)		3/4” Male
153.331050	5	11 (279 mm)	14-3/4 (375 mm)		3/4” Male

TABLE 6

Expansion Tank Sizing Chart

	Inlet*		Water Heater Capacity (Gallons)
	Water
Expansion	Pressure		30	40	50	66	82
Expansion	40psi	2		2	2	5	5
Tank	50psi	2		2	2	5	5
Capacity	60psi	2		2	5	5	5
Needed	70psi	2		2	5	5	5
	80psi	2		5	5	5	5

*Highest recorded inlet water pressure in a 24 hour period or regulated water pressure.

FIGURE 42.

Strange Sounds

Possible noises due to expansion and contraction of some metal parts during periods of heat-up and cool-down do not represent harmful or dangerous conditions.

Condensation causes sizzling and popping within the burner area during heating and cooling periods and should be considered normal. See “Condensation” section.

Draft Hood Operation

Check draft hood operation by performing a worst case depressurization of the building. With all doors and windows closed, and with all air handling equipment and exhaust fans operating such as furnaces, clothes dryers, range hoods and bathroom fans, a match flame should still be drawn into the draft hood of the water heater with its burner firing. If the flame is not