Start UP Conditions, Condensate, Smoke/Odor

FOR YOUR INFORMATION

START UP CONDITIONS

CONDENSATE

Whenever the water heater is ﬁlled with cold water, some condensate will form while the burner is on. A water heater may appear to be leaking when in fact the water is condensate. This usually happens when:

a.A new water heater is ﬁlled with cold water for the ﬁrst time.

b.Burning gas produces water vapor in water heaters, particularly high efﬁciency models where ﬂue temperatures are lower.

c.Large amounts of hot water are used in a short time and the reﬁll water in the tank is very cold.

Moisture from the products of combustion condense on the cooler tank surfaces and form drops of water which may fall onto the burner or other hot surfaces to produce a “sizzling” or “frying” noise.

Because of the suddenness and amount of water, condensate water may be diagnosed as a “tank leak”. After the water in the tank warms up (about 1-2 hours), the condition should disappear.

Do not assume the water heater is leaking until there has been enough time for the water in the tank to warm up.

An undersized water heater will cause more condensation. The water heater must be sized properly to meet the family’s demands for hot water including dishwashers, washing machines and shower heads.

Excessive condensate may be noticed during the winter and early spring months when incoming water temperatures are at their lowest.

Good venting is essential for a gas ﬁred water heater to operate properly as well as to carry away products of combustion and water vapor.

SMOKE/ODOR

It is not uncommon to experience a small amount of smoke and odor during the initial start-up. This is due to burning off of oil from metal parts, and will disappear in a short while.

THERMAL EXPANSION

Water supply systems may, because of such events as high line pressure, frequent cut-offs, the effects of water hammer among others, have installed devices such as pressure reducing valves, check valves, back ﬂow preventers, etc. to control these types of problems. When these devices are not equipped with an internal by-pass, and no other measures are taken, the devices cause the water system to be closed. As water is heated, it expands (thermal expansion) and closed systems do not allow for the expansion of heated water.

The water within the water tank expands as it is heated and increases the pressure of the water system. If the relieving point of the water heater’s temperature-pressure relief valve is reached, the valve will release the excess pressure. The temperature-pressure relief valve is not intended for the constant relief of thermal expansion. This is an unacceptable condition and must be corrected. It is recommended that any devices installed which could create a closed system have a by-pass and/or the system have an expansion tank or device to relieve the pressure built by thermal expansion in the water system. Expansion tanks are available through Sears stores and Sears Service Centers. Contact Sears Service Center for assistance in controlling these situations, see Figure 27.

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

Expansion Tank Sizing Chart

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

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.

FIGURE 27.

FOR YOUR INFORMATION