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

ELECTRICAL CONNECTIONS
To be certain that all of the air is out of the water heater, open the HOT
water faucet on your xtures until constant water ows from them. If air
remains in the tank, the element will be damaged when the electric cord
is plugged in.
Connect the water heater to a GROUNDED OUTLET.
The water heater is tted with a power cord that is intended to
plug into a grounded 110-120 V/AC receptacle. Adhere to all
pertinent State and local codes. Install the correct size circuit
breaker into the master panel. The WaiWela WM water heater
was manufactured and wired in accordance with UL require-
ments.
The water heater is equipped with an overheat limiting device
with a manual reset. Also known as the temperature high limit,
this device has been factory installed to interrupt the power sup-
ply in the event of a thermostat failure.
This water heater is designed for ONLY 110-120V electrical
service!!!!! DO NOT CONNECT TO HIGHER OR LOWER VOLTAGE.
Failure to use proper voltage may result in personal injury and/or prop-
erty damage. If the supplied electrical power cord is either damaged or
not long enough, do NOT use an extension cord. Have a licensed electri-
cian replace the power cord.
Page 10

INSTRUCTIONS FOR USE
CONGRATULATIONS! You are now ready to use your water
heater. Run the hot water at a nearby sink and evaluate the hot
water temperature. Make any temperature adjustment using the
section below:
SETTING THE THERMOSTAT:
The water heater is equipped with an adjustable thermostat that once
set will automatically control water temperature. The red indicator lamp
remains illuminated while the water is being heated. If the water in the
tank is at the desired temperature the lamp will NOT be illuminated.
The temperature adjusting knob will increase the temperature by turning
the knob clockwise and decrease the water temperature by turning the
knob counter clockwise.
When not being used for a lengthy period of time, you can conserve
energy by reducing the water temperature setting.
SETTING THE FREEZE PROTECTION:
When the water heater is not being used for an extended period of time
and there is a risk of freezing, either unplug and drain the water heater
OR turn the thermostat knob to the snowake position to guard against
freezing. This position will keep the internal water temperature above
the freezing point. See photo below.
Temperature adjusting knob in “Freeze Protection” position
Page 11

MAINTENANCE INSTRUCTIONS
Do not attempt to repair this water heater yourself. Call a
service person (plumber or electrician) for service assistance.
Always unplug the power supply cord when the water is turned
off or when servicing or draining the water heater.
Before calling for service, rst conrm that the water heater is
properly lled and that 110VAC power has not been interrupted.
WARNING: Before servicing or cleaning the water heater, turn
off the POWER switch and disconnect the power cord from the
electrical outlet.
NOTE: For most maintenance operations, the water heater will
be drained. In all cases before draining rst turn off the POWER
switch and then unplug power cord.
DRAINING AND REMOVING THE WATER HEATER:
1. Unplug the water heater.
2. Open a hot water faucet to let hot water run out. Allow water to
ow until water is no longer hot.
3. Turn off the cold water supply to the water heater.
4. Close the hot water faucet.
5. Disconnect the water heater from both the hot and cold water
connections.
6. If possible siphon out remaining water.
7. Carefully detach the water heater from the wall.
8. Tilt the water heater to drain remaining water out of the heater.
REMOVING THE HEATING ELEMENT:
1. Turn off power supply, unplug water heater power cord and drain
(see above).
2. Remove cover.
3. Remove all the line wires from the heating element.
4. Unscrew the heating element retaining nuts.
5. Remove the element.
Page 12

DESCALING THE HEATING ELEMENT:
Scale deposits can affect the heating capability of the element. Heavy
scale can even cause the element to burn out. The element can be
descaled chemically or manually.
1. Remove the heating element (see above).
2. To descale chemically, soak the heating element in white vinegar or
other descaling solution and then rinse well with fresh water.
3. To descale manually, let element dry and then using a non
metallic brush similar to a tooth brush; brush the residue from the
element. Avoid damaging the surface of the element.
4. Reinstall the element and gasket.
5. Rell tank with water before turning on the power to the water
heater.
REPLACING THE HEATING ELEMENT:
1. Unplug and drain the water heater (see prior instructions).
2. Remove heating element noting original positions of all connections.
3. Install new element with gasket making sure the new element and
gasket are positioned correctly.
4. Tighten retaining nuts and make the wire connections to their
original locations.
CHANGING THE THERMOSTAT:
1. Turn off the power switch and unplug the water heater from
the electric outlet.
2. Drain and remove the water heater. (see page 12)
3. Remove six screws retaining the bottom panel of the water heater
and remove the panel.
4. Remove thermostat knob and unscrew two retaining screws. It may
be necessary to pry the knob off of the
thermostat spindle. Now remove front panel.
5. Disconnect the push-pull wire connectors on
the thermostat noting which connector goes
to which terminal. Terminals are marked.
6. Remove the thermostat probe from the well.
7. Install new thermostat, attach wires and
tighten screws.
Thermostat
Page 13

RESETTING THE HIGH LIMIT SWITCH:
For various reasons the high limit safety shut off switch will occasionally
shut the water heater down. This shut down will occur when water tem-
peratures exceed 190°F. Power is automatically turned off to the heating
element. The shut off device may activate as a result of a power outage
or an electrical storm.
NOTE: Do not attempt to reset the high limit switch without rst allow-
ing the water heater to cool down the high temperature water inside the
heater.
WARNING: Do not tamper with the reset button to over ride overheating
shut down.
1. Turn off the power switch and unplug the water heater from
the electric outlet.
2. Drain and remove the water heater. (see page 12)
3. Remove six screws retaining the bottom panel of the water heater
and remove the panel. Locate the high limit reset button.
4. Depress the small red button in the center of the junction box,
replace the bottom panel and place the water heater back into
service.
NOTE: A lower temperature setting saves energy and reduces the risk of
scalding.
CAUTION!: Call a technician if the high limit needs to be reset frequently.
High Limit Reset Button
Heating Element
Page 14

TROUBLE SHOOTING
PROBLEM: Water does not get hot
1. Make sure the power supply is on and working.
2. If light does not come on, check that the reset button is pushed in;
follow steps from previous section.
3. If the indicator light is illuminated, but water temperature does not
get hot at the sink, test for a plumbing crossover as follows; shut
off cold water supply to water heater and open hot water tap. There
should be no water owing. Any continuous ow indicates a cross
over which will effect the temperature and will need to be corrected.
4. If there is no crossover, then replace the heating element
(see previous sections).
PROBLEM: Indicator light not on
1. If the light does not come on, but water gets hot, check for faulty
bulb.
2. Check reset button; follow steps from previous section.
PROBLEM: Brown water
1. Brown or rusty water indicates a “spent” anode rod. Replace anode
rod.
PROBLEM: Odor in water
1. Smelly water could be due to an unusual reaction between local
water and the heater’s anode rod. Check anode rod.
PROBLEM: Water is too hot
1. Turn the temperature knob counter clockwise to a lower
temperature setting. If temperature does not lower within 60
minutes, then replace thermostat.
PROBLEM: Water is not hot enough
1. Under Instructions for Use, see “Setting the thermostat”.
PROBLEM: Water is leaking
1. Turn off power switch and unplug water heater from 110 VAC
outlet.
2. Check water ttings and T&P tting in the top of the tank.
3. Remove cover and inspect heating element gasket.
Page 15

No. Name of Part Qty.
1 Tank Component 1
2 Thermostat 1
3Temp. Adjust Panel 1
4 Inside Wiring Assembly 1
5Cross Screws 6
6 Inside Cover 1
7 Bottom Cover 1
8 Indicate Light Cover 1
9Power Indicate Light 1
10 Support 1 2
11 Support 2 2
12 Thermal Block 1
13 Wire Press Plate 1
14 Heating Element 1
15 Over Heat Limiter 1
16 Heating Element Gasket 1
17 Temp. Control Knob 1
18 Red Circle 1
19 Front Cover 1
Schematic Disassembly
WM-2.5 & WM-4.0
Parts List WM-2.5 & WM-4.0
Page 16
22
92
1
7
5
16 33
29
30
12
13
15
34 35
36
23
6
27
14
18
11
32 31
25
37
38
26
20
24
10
8
28
3
21
17
19
4
No. Name of Part Qty.
20 Back Cover 1
21 Power Switch 1
22 Power Switch Box 1
23 Power Cord 1
24 Screw 2
25 Blue Circle 1
26 Power Cord Sheath 1
27 Power Cord Sheath Press 1
28 Cross Screw 2
29 Connect Plate 1
30 Cross Screw 1
31 Flat Gasket 4
32 Copper Screw 4
33 Aluminium Anode Rod 1
34 Bolt 1
35 Cross Screw 1
36 Cross screw 2
37 Red Thread Cover 1
38 Blue Thread Cover 1

WaiWela Mini Tank Water Heaters Models WM-2.5
and WM-4.0 – Limited SIX (6) YEARS WARRANTY
Coverage
Efcient Technology Sales, LLC (hereinafter “ETS”) guarantees this wa-
ter heater to the Owner (hereinafter “Owner”) of the water heater at the
original installation location against defects in material and workmanship
for the periods specied below.
Warranty Period
1. When a failure of the INNER TANK of a WaiWela Mini Tank water heater, in-
stalled in a single family, residential application and exposed to normal usage (not
including recirculating applications), occurs within six (6) years from the date of the
original installation and is supplied with potable water, deemed not to be hard wa-
ter, and such failure is proven to be a result of a defect in material or workmanship
or within one (1) year if used as part of a recirculating application or in a non single
family residential application, or with hard water, ETS will furnish to such owner a
new water heater of the then prevailing comparable model.
2. If any component part (other than the inner tank) is proven to be defective in
material or workmanship within two (2) years from date of original installation in a
single family, residential application used with potable water deemed not to be hard
water or within one (1) year if used as part of a recirculating system, or with hard
water, or if used in other than a single family residential dwelling, ETS will furnish the
Owner with a replacement of the defective part(s).
3. Verication of Date of Original Installation- When Owner can not verify or
document the original date of installation, the warranty period begins on the date of
manufacture marked on the tag afxed to the water heater.
Exclusions
1. THIS LIMITED WARRANTY SHALL BE THE EXCLUSIVE WARRANTY
MADE BY THE MANUFACTURER AND IS MADE IN LIEU OF ALL OTHER
WARRANTIES, EXPRESSED OR IMPLIED (WHETHER WRITTEN OR ORAL),
INCLUDING, BUT NOT LIMITED TO, WARRANTIES OR MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.
2. The Manufacturer shall not be liable for any incidental, consequen-
tial, special or contingent damages or expenses arising, directly or indi-
rectly, from any defect in the water heater or the use of the water
heater.
3. The Manufacturer shall not be liable for any water damage aris-
ing, directly or indirectly, from any defect in the water heater component
part(s) or from its use.
Page 17

4. Manufacturer shall not be liable under this warranty if:
a) The water heater or any of its component parts has been
subject to excessive water pressure, misuse, abuse, alteration,
neglect or accident, or
b) The water heater has not been installed in accordance with the
applicable local plumbing, electrical and/or building code(s) and/or
regulation(s), or
c) The water heater has not been installed in accordance with the
printed manufacturer’s instructions, or
d) The water heater is not continuously supplied with potable
water, otherwise described as DRY FIRING
e) The water heater is exposed to conditions resulting from oods,
earthquakes, winds, re, lightning or circumstances beyond the
control of the manufacturer
f) The water heater is installed by non-qualied personnel.
5. The OWNER and not the Manufacturer or his agent/representative
shall be liable for and shall pay for all eld charges for labor or other ex-
penses incurred in the removal and/or repair of the water heater or any
expense incurred by the Owner in order to repair the water heater.
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCI-
DENTAL OR CONSQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR
EXCLUSION MAY NOT APPLY TO YOU. THIS WARRANTY GIVES YOU SPE-
CIFIC LEGAL RIGHTS AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH
MAY VARY FROM STATE TO STATE.
IMPORTANT: OWNER SHOULD RETAIN THIS DOCUMENT.
READ NOTE
NOTE: Most tank water heaters eventually leak. Your WaiWela quality
water heater should be installed in such a manner that if it should leak,
the resulting ow of water will not cause damage to the area in which it
is installed.
Page 18

HOW THE OWNER CAN SECURE SERVICE
ASSISTANCE OR MAKE A WARRANTY CLAIM
1. Owner should contact the dealer who sold the water heater covered
by this warranty or
2. Owner should submit the warranty claim directly to ETS at the
address listed below, and they will arrange for the handling of the
claim.
3. Whenever a warranty service request is made, be sure to include
Proof of Purchase, the water heater model number and the date of
manufacture, date of installation, Dealer’s name and the watts and
voltage.
4. When returning the water heater or component part(s), they must
be individually tagged and identied with the Returned Goods
Authorization # issued by ETS and shipped prepaid to ETS at the
address below.
Efcient Technology Sales, LLC
5350 Joliet Street
Denver, CO 80239
800 605-6542
303 339-4900
FAX [phone]
www.waiwela.com
Page 19