Kenmore 334 Thermal Expansion Tank, Expansion Tank Sizing, Strange Sounds, Draft Hood Operation

Start Up Conditions

Thermal Expansion

Property Damage Hazard

-Avoid water heater damage,

• Install thermal expansion tank or device if necessary.

. Contact qualified installer or service agency.

Water supply system may, because of such events as high line pressure, frequent cut-offs, and the effects of water hammer 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 heater tank expands as it is heated and increases the pressure of the water system. If the relieving

point of water heater's temperature-pressure relief valve is

reached, the valve will relief 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. 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 26.

Thermal Expansion			Tank	Specifications
	Tank	Dimensions					Pipe
Mode!
	Capacity		in inches				Fitting
Number	in Gallons	Diameter		Lenoth			On	Tank
153.331020	2	18 {203	ram)	I2-3/4	{323	ram)	3/4"	Mate
153.331050	5	11 (279	ram)	I4-3/4	(375	ram)	3/4"	Mate
	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	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.

		WATER HEATER	(3)
H_T	r'nRr_ _"	COLD WATER	PRESSURE
.......	_[_.._,_	iNLET FITTING	*'_REDUCING

	!			BY-PASS
		PRESSURE	GAUGE	INLET	COLD
				WATER SHUTOFF
	RECOMMENDEDiNSTALLATiON
-- --	--	(VERTICAL MOUNTING)
WATER	HEATER
COLD	WATER
iNLET	FiTTiNG		FLOOR,	CEILING	JOIST, ETC.
	)k	II	Jl
r__ HOT	COL C		.,_----STRAPPING

J f

PRESSURE GAUGE iNLET COLD

WATER SHUT-OFF

ALTERNATE RECOMMENDEDINSTALLATION (HORIZONTALMOUNTING)

FIGURE 26.

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

23