Waiwela MiniTank WM-2.5 Supplement

Electric Mini Tank
Water Heaters
WM-2.5 & WM-4.0
Installation and Operating Instruction Manual
http://waterheatertimer.org/How-to-install-under-counter-water-heater.html

Table of Contents
Important Safety Instructions 2
Technical Data 3-4
General Information 5
Technical Description 6
Installation Instructions 6-10
Plumbing Connections 7
Temperature & Pressure Relief Valve 7-8
Filling The Water Heater 9
Electrical Connections 10
Instructions For Use 11
Maintenance Instructions 12-14
Trouble Shooting 15
Schematic Disassembly & Parts List 16
Warranty 17-19
Page 1

IMPORTANT SAFETY INSTRUCTIONS
WARNING: When using electrical appliances, safety precautions to reduce the risk
of re, electric shock or injury to persons should be followed, including:
1. READ ALL INSTRUCTIONS BEFORE USING THIS WATER HEATER.
2. This water heater must be grounded. Connect only to properly grounded outlet.
See “GROUNDING INSTRUCTIONS” found on page 10.
3. Install or locate this water heater only in accordance with the provided
installation instructions.
4. Use this water heater only for its intended use as described in this manual.
5. Do not use an extension cord set with this water heater. If no receptacle is
available adjacent to the water heater, contact a qualied electrician to have
one properly installed.
6. As with any appliance, close supervision is necessary when used by children.
7. Do not operate this water heater if it has a damaged cord or plug, if it is not
working properly, or if it has been damaged or dropped.
8. This water heater should be serviced only by qualied service personnel.
Contact nearest authorized service facility for examination, repair, or adjustment.
SAVE THESE INSTRUCTIONS
The manufacturer and/or distributor is not responsible for damages caused by
improper installation, or by non observance of the instructions in this manual.
A QUALIFIED, LICENSED TECHNICIAN MUST ALWAYS INSTALL THE WATER HEATER
AND CONDUCT ALL SUBSEQUENT SERVICE WORK AND/OR MAINTENANCE.
IMPORTANT!!!
NEVER TURN THE WATER HEATER POWER ON UNTIL THE TANK IS COMPLETELY FULL
AND WATER IS FLOWING OUT OF THE HOT WATER FAUCET.
Page 2

Technical Data
MODEL WM-2.5 WM-4.0
Capacity gallons 2.5 4.0
Voltage Vac 110-120 110-120
Power at 120 Vac Watts 1440 1440
Max. Water Pressure psi 150 150
Weight (empty) lbs. 20 24
Amperage Amps 12 12
Temperature and
Pressure Relief Valve
Water inlet
Water outlet
water outlet water inlet
Assembly Figure
Water Flow Figure
Page 3

$
% &
Model WM-2.5 WM-4.0
A (inch) 14 1/2” 19 1/4”
B (inch) 11 3/4” 11 3/4”
C (inch) 10 3/8” 10 3/8”
Dimensions
Switch
Heating element
(
1
/
/
1
Switch
Thermostat
Indicate Light
Heating Element
Power Plug
Switch
Overheat Limiter
Wire
Support
Schematic Construction
Wiring Diagram
Page 4

GENERAL INFORMATION
The WaiWela Mini Tank water heaters can be used in most under the
counter, point of use applications. Models WM-2.5 and WM-4.0 are
designed to supply hot water for all hand wash and kitchen sinks in a
residential, commercial or industrial environment.
The WM-2.5 and WM-4.0 can replace traditional central hot water heat-
ers thereby conserving water and reducing energy waste.
The WaiWela Mini tank water heaters are lightweight and compact and
manufactured for easy installation. The WM-2.5 and WM-4.0 are
designed to be mounted on the wall.
WM-2.5 and WM-4.0 are designed to operate at 150 psi maximum
water pressure. Install a pressure reducing valve if your water pressure
is greater than 150 psi.
CAUTION!: The manufacturer cannot be responsible for the damage
caused by improper installation or by failure to follow instructions in this
manual. Comply with the Installation Instructions before connecting to
electrical outlet.
CAUTION!: The thermostat has been pre-set at the factory between
41°C (105°F) and 45°C (113°F).
CAUTION!: Hydrogen gas can be produced in a hot water system
served by this heater that has not been used for a long period of time
(generally 2 weeks or more). Hydrogen gas is extremely ammable. To
reduce the risk of injury under these conditions, it is recommended that
the hot water faucet be opened for several minutes at the nearest and
most distant sink being served by this water heater before using any
electrical appliance connected to the hot water system i.e. Dishwasher.
If hydrogen gas is present, there will probably be an unusual sound such
as air escaping through the faucet as the water begins to ow. There
should be no smoking or open ame near the faucet at this time.
WARNING: Installer should review the contents of this manual with the
owner upon completion of the installation, and the manual should remain
with the owner and placed in a location close to the water heater.
Page 5

TECHNICAL DESCRIPTION
There are two WaiWela Mini tank models, a 2.5 gallon model and a 4.0
gallon model. The pressure vessel (water tank) is welded, glass lined
steel and is equipped with an anode rod.
The water heater is equipped with a thermostat and a high limit
temperature switch. A temperature/pressure relief valve is supplied with
the unit.
INSTALLATION INSTRUCTIONS
WM-2.5/WM-4.0
The installation must be completed by a licensed professional. All state
and local codes must be adhered to. The manufacturer will not be liable
for any damages because of failure to comply with these installation
instructions or because of improper installation performed by an
unqualied installer.
CHOOSE A LOCATION that allows ease of access for maintenance or
servicing, ideally installed at least 8” to 9” from the ceiling (inside top of
cabinet) or any adjacent walls.
WALL MOUNTING
Fasten the supplied mounting bracket to the wall. Use screws that are
suitable for the wall material and the weight of the water heater lled to
capacity (WM-2.5 =41 pounds and WM-4.0 = 57 pounds). Hang the
water heater on the bracket and pull downwards on the water heater
to insure that both “ngers” of the bracket are seated in the mounting
slots. Conrm your water piping orientation (hot and cold) before wall
mounting. ONLY INSTALL IN VERTICAL POSITION.
Heater can sit on the oor. Conrm water piping orientation before
nalizing on oor. ONLY INSTALL IN VERTICAL POSITION!
Models WM-2.5 and WM-4.0 can be installed under the sink.
Page 6

PLUMBING CONNECTIONS
Connect the cold water inlet pipe to the inlet nipple (marked with a blue
ring) and the hot water outlet pipe to the outlet nipple (marked with a red
ring).
IMPORTANT: If Water pipes are copper or bronze, use dielectric
connections to prevent corrosion. Failure to provide dielectric insulation
may result in premature tank or nipple failure and may void your
warranty. Insure that the water heater is installed in a level position.
Install a shut off valve on the cold water side of the water heater. The
valve is for servicing and the valve should be in the open position when
the water heater is in operation. In order to protect the water heater
from heat damage due to soldering, solder a piece of tubing to a threaded
UNION tting before screwing the UNION to the tank. DO NOT APPLY
HEAT DIRECTLY TO INLET OR OUTLET CONNECTIONS.
TEMPERATURE AND PRESSURE RELIEF VALVE:
CAUTION!: Install the Temperature/Pressure Relief Valve
supplied with the water heater!
Install a discharge pipe from the temperature/pressure relief
valve terminating at a sink or drain. DO NOT CAP OR PLUG THE
END OF THE DISCHARGE PIPE. THE DISCHARGE PIPE MUST BE
UNOBSTRUCTED AND FULL SIZED.
The T/P valve is certied by a nationally recognized test lab that
maintains periodic inspections of the listed equipment and meets the
requirements for relief valves and automatic shut off devices for hot
water supply systems ANSI 121.22-1979.
The T/P valve is marked with a maximum pressure, which does not
exceed the maximum working pressure of the water heater (150 PSI).
Install the T/P valve into the threaded opening at the top of the
water heater and orient the discharge tubing so that any dis-
charge from the valve will exit within 6 inches above, or at any
distance below the structural oor, and cannot contact any live
electrical part.
Page 7

T/P Valve Discharge pipe:
1. Must NOT be smaller in diameter than the outlet
diameter of the valve, or have any reducing couplings.
2. Must NOT be plugged or blocked.
3. Must be made of suitable material for hot water.
4. Must not be over 15’ in length.
5. Must not have more than two elbows.
6. Must terminate at an adequate drain.
7. Must not have a shut off valve between relief valve and
tank or relief valve and termination of discharge.
CLOSED SYSTEM THERMAL EXPANSION: Periodic discharge of the
T/P relief valve or failure of the element gasket may be due to
thermal expansion in a closed water supply system. The
water utility supply meter may contain a check valve, backow
preventer or water pressure reducing valve which will create a
closed water system. During the heating cycle of the water
heater, the heated water expands causing pressure inside the
water heater to increase. The T/P relief valve may discharge hot
water under these conditions which results in a loss of energy
and a build up of lime on the relief valve seat.
To prevent this from happening, there are two recommendations:
1. Install a diaphragm-type domestic hot water expansion
tank (suitable for potable water) on the cold water
supply line. The expansion tank must have a minimum
capacity of 1.5 U.S. gallons for every 50 gallons of
stored water.
2. Install a 125 PSI pressure relief valve in the cold
water supply line. Make sure the discharge of this valve
is directed to an open drain and protected from
freezing. Contact your local water utility or plumbing
inspector for information on how to control this
situation. Never plug the outlet of the relief valve.
Page 8

FILLING THE WATER HEATER
CAUTION!: Before plugging the water heater electric cord into an
outlet, be sure that the system is completely charged with water
and ALL AIR IS REMOVED.
Before connecting the power, ll the tank and system with water and
check for leaks. To be sure that all air is out of the water system, open
the hot water faucets on your xtures until constant water ows from
them. Otherwise any air remaining in the tank will cause the water
heater element to self destruct.
Filling the water heater:
1. Open the hot water faucet.
2. Open the cold water supply valve.
3. When continuous water ows out of the faucet, the tank is lled.
4. Close the hot water faucet.
5. Check entire system for leaks.
Page 9