Amtrol ST-25V, ST-5, ST-12, ST-8, ST-210V User Manual

THERMAL EXPANSION TANKS

FOR POTABLE WATER

INSTALLATION & OPERATION INSTRUCTIONS

Models ST-5 through ST-210V

Models T-5 through T-12

NOTE: Inspect for shipping damage. Notify freight carrier or store where purchased immediately if damage is present. To avoid risk of personal injury
and property damage, if the product appears to be malfunctioning or shows signs of corrosion, call a qualified professional immediately. Current copies

of the product manual can be viewed at www.amtrol.com. Use proper safety equipment when installing.

THIS IS THE SAFETY ALERT SYMBOL. IT IS USED TO ALERT YOU TO POTENTIAL PERSONAL INJURY AND OTHER
HAZARDS. OBEY ALL SAFETY MESSAGES THAT FOLLOW THIS SYMBOL TO REDUCE THE RISK OF PERSONAL
INJURY AS WELL AS PROPERTY DAMAGE.

READ CAREFULLY THE PRODUCT INSTALLATION,

FAILURE TO FOLLOW THE INSTRUCTIONS AND WARNINGS IN THE
MANUAL MAY RESULT IN SERIOUS OR FATAL INJURY AND/OR
PROPERTY DAMAGE, AND WILL VOID THE PRODUCT WARRANTY.
THIS PRODUCT MUST BE INSTALLED BY A QUALIFIED
PROFESSIONAL. FOLLOW ALL APPLICABLE LOCAL AND STATE
CODES AND REGULATIONS, IN THE ABSENCE OF SUCH CODES,
FOLLOW THE CURRENT EDITIONS OF THE NATIONAL PLUMBING
CODE AND

temperatures or where the temperature can exceed 200°F and do not
exceed the maximum working pressure specified for this Product.w

explode, causing serious or fatal injury, leaking or flooding and/or
property damage. To minimize risk, a licensed professional must install
and periodically inspect and service the Product. A drip pan connected to
an adequate drain must be installed if leaking or flooding could cause
property damage. Do not locate in an area where leaking could cause
property damage to the area adjacent to the appliance or to lower floors
of the structure.

CALIFORNIA PROPOSITION 65 WARNING! This product contains a
chemical known by the State of California to cause cancer and to cause
birth defects or other reproductive harm. (California Installer/Contractor

- California law requires that this notice be given to consumer/end user
of this product.) For more information: www.amtrol.com/prop65.html

NATIONAL ELECTRIC CODE, AS APPLICABLE.

OPERATING AND MAINTENANCE MANUAL.

USE ONLY WITH POTABLE WATER SYSTEMS.

Do not operate in a setting with freezing

This Product, like most Products under pressure,
may over time corrode, weaken and burst or

temperatures in excess of 200°F. Do not adjust the pre-charge or
re-pressure this Product except during installation or regular inspection.
Replace the Product and do not adjust the precharge if corroded,
damaged or with diminished integrity. Adjustments to pre-charge must be
done at ambient temperature only. Failure to properly size the Product or
follow these instructions may result in excessive strain on the system and
may lead to Product failure, serious or fatal personal injury, leakage and/
or property damage.

working pressure designated in the Product Manual, whichever is less.
At least once every 3 years or if discharge is present, a licensed
contractor should inspect the temperature and pressure relief valve and
replace if corrosion is evident or the valve does not function. FAILURE

TO INSPECT THIS VALVE AS DIRECTED COULD RESULT IN
UNSAFE TEMPERATURE OR PRESSURE BUILD-UP WHICH CAN
RESULT IN PRODUCT FAILURE, SERIOUS INJURY OR DEATH AND/
OR SEVERE PROPERTY DAMAGE AND VOID THE PRODUCT
WARRANTY.

You should test for corrosive elements, acidity, total solids and other
relevant contaminants, including chlorine and treat your water appropriately
to insure satisfactory performance and prevent premature failure.

RUPTURE OR EXPLOSION HAZARD. Do not

expose Product to freezing temperatures or

A relief valve must be installed to prevent pressure

in excess of local code requirement or maximum

Chlorine & Aggressive Water: The water quality

can significantly influence the life of this Product.

PLEASE READ THE FOLLOWING INSTRUCTIONS CAREFULLY

IMPORTANT GENERAL SAFETY INFORMATION -

ADDITIONAL SPECIFIC SAFETY ALERTS APPEAR IN THE FOLLOWING INSTRUCTIONS.

Pre-Installation

1 Ensure expansion tank is sized properly for application (Figure 1).

2. Remove plastic cap from air valve.

3. With tank empty of water, adjust air precharge to match cold water
supply pressure.

4. Replace and tighten plastic cap on air valve.

5. Therm-X-Trol® ST-5, ST-8, ST-12 only: Insert Turbulator into
connector (optional).

FAILURE TO PROPERLY SEAL VALVE CAP
WILL RESULT IN LOSS OF PRECHARGE
CAUSING PRODUCT TO FAIL.

3. Before the initial firing of the water heater, open any hot water fixture
and draw water until all air is removed from the system. Turn the water
heater temperature control to desired ending temperature (see water
heater instructions). Do not set temperature higher than the expansion
tank maximum.

4. To relieve initial thermal expansion, slightly open a hot water faucet.
Continue until water heater aquastat temperature is satisfied. Once
heater is at its operating range, no further bleeding of expanded water
is required.

5. The water heater and expansion tank will now be operational. The
expansion tank will control pressure increases caused by thermal
expansion to a level below the water heater relief valve setting.

Maintenance

Installation

1. Install the expansion tank on the cold water supply line to the water
heater at a point between the water heater and backflow preventer or
other one-way device (Figure 2).

Mount tank vertically only. Ensure the piping can

Models ST-25V through ST-210V are floor

2. Once the expansion tank is installed, check the cold water supply line
for any leakage. Make repairs if necessary.

Figure 1.

Expansion Tank Volume (Gal.)

Maximum Temperature Setting 140°F

Water Heater

Size

(gals.)

40 2.0 2.0 2.0

50 2.0 2.0 2.0

60 3.2 3.2 3.2

80 3.2 3.2 4.4

120 4.4 4.4 10.3

Sizing based on: 40°F incoming water temperature; 150 psi T&P safety relief valve; Pre-charge equal to static supply pressure.
For larger applications: Visit amtrol.com, download the AMTROL App or contact Technical Support at 401.535.1216.

Static Supply Pressure (psig)

support the entire weight of the tank when full
of water.

standing and may not be hung from the piping.

Maximum Temperature Setting 160°F

Water Heater

40 60 80

Size

(gals.)

40 2.0 2.0 3.2

50 2.0 3.2 3.2

60 3.2 3.2 4.4

80 3.2 4.4 10.3

120 4.4 10.3 10.3

Expansion Tank Volume (Gal.)

Static Supply Pressure (psig)

A professional plumber should check the complete system,
including the expansion tank, yearly and more frequently as the
system ages. Checking the precharge allows a small quantity of
air to escape and can result in an insufficient air charge. Always
check the precharge while the tank is isolated and empty of water,
and be sure to maintain the proper precharge whenever the tank
is inspected.

Warranty

ST-5 through ST-25V Models: Five (5) Year Limited Warranty
ST-30V through ST-210V Models: One (1) Year Limited Warranty
T-5 through T-12 Models: One (1) Year Limited Warranty

Visit www.amtrol.com for complete warranty details.

Maximum Temperature Setting 180°F

Water Heater

40 60 80

Size

(gals.)

40 3.2 3.2 3.2

50 3.2 3.2 4.4

60 3.2 4.4 10.3

80 4.4 10.3 10.3

120 10.3 10.3 10.3

Expansion Tank Volume (Gal.)

Static Supply Pressure (psig)

40 60 80

Figure 2.

Backflow Preventor, Check Valve
or Pressure Reducing Valve

Cold

Water

Supply

Thermal Expansion Tank

Turbulator Installation: Therm-X-Trol® Models Only

3/4” Threaded Tee

Turbulator

Tank Connector

In-Line Models Stand Models

Press Turbulator fully

into connector prior

to installing tank.

Water

Heater

Hot Water

T & P
Relief
Valve

Cold

Water

Supply

1400 Division Road, West Warwick, RI USA 02893

T: 800.426.8765 F: 800.293.1519

www.amtrol.com

© 2014 AMTROL Inc. Part #: 9015-087 (06/14)

Backflow Preventor
Check Valve or
Pressure Reducing Valve

Thermal

Expansion Tank

Water

Heater

Hot Water

T & P
Relief
Valve

Mark of the

Originator