A.O. Smith Voltex Hybrid Electric PHPT-80 Operating manual

1
A.O. Smith – Voltex™
Hybrid Electric
Heat Pump Water Heater
Installation
Instructions and
Use & Care Guide
To obtain technical, warranty or service assistance during or after
the installation of this water heater, call toll free
1-800-527-1953
When calling for assistance, please have the following
information ready:
1. Model number
2. 7 Digit product number
3. Serial number
4. Date of installation
5. Place of Purchase
Water Heater Safety ............................................................................... 2
Installing Your Water Heater .................................................................3-9
Consumer Information ................................................................ 3
Consumer Responsibilities ......................................................... 3
Unpacking Instructions ............................................................ 3-4
Location Requirements ............................................................... 4
Water System Piping ................................................................5-6
Temperature & Pressure Relief Valve....................................... 7-8
Electrical Requirements ........................................................... 8-9
Installation Checklist .............................................................................. 10
Operating Your Water Heater ........................................................... 11-13
Before Using ............................................................................. 11
Water Temperature Regulation ................................................. 11
Adjusting the User Interface Module/ Operational Mode .......... 12
Operational Conditions ............................................................. 13
Maintenance of Your Water Heater ..................................................14-15
Temperature and Pressure Relief Valve .................................... 14
Draining and Flushing................................................................ 14
Heating Element Replacement.............................................14-15
Cleaning the Heat Pump ........................................................... 15
Diagnostic Codes .................................................................................. 16
Troubleshooting Chart ........................................................................... 17
Repair Parts Illustration ......................................................................... 18
Notes... ..............................................................................................19-20
Table of Contents Page
318257-000
February 2010

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Your safety and the safety of others are very important.
We have provided many important safety messages in this manual and on your appliance. Always read and obey all
safety messages.
This is the safety alert symbol.
This symbol alerts you to potential hazards that can kill or hurt you and others.
All safety messages will follow the safety alert symbol and either the word “DANGER” or
“WARNING.” These words mean:
You can be killed or seriously injured if you don’t
immediately follow instructions.
You can be killed or seriously injured if you don’t
follow instructions.
All safety messages will tell you what the potential hazard is, tell you how to reduce the chance of injury, and tell you
what can happen if the instructions are not followed.
Important Safety Instructions
CAUTION: Hydrogen gas is produced in a hot water system served by this heater that has not been used for a long
period of time (2 weeks or more). Hydrogen gas is extremely flammable. To reduce the risk of injury under these
conditions, it is recommended that the hot water faucet be opened for several minutes at the kitchen sink before
using any electrical appliance connected to the hot water system. When hydrogen is present, there will probably be
an unusual sound such as air escaping through the pipe as the water begins to flow. There should be no smoking or
open flame near the faucet at the time it is open.
The California Safe Drinking Water and Toxic Enforcement Act requires the Governor of California to publish a list of
substances known to the State of California to cause cancer, birth defects, or other reproductive harm, and requires
businesses to warn of potential exposure to such substances.
WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects, or other
reproductive harm.
This appliance can cause low-level exposure to some of the substances included in the Act.
WATER HEATER SAFETY
IMPORTANT: The heat pump portion of this water heater uses R-134a refrigerant. See the data plate on the heat pump
compressor for charge level.

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INSTALLING YOUR WATER HEATER
Consumer Information
This water heater should be installed in accordance with
the local code authority having jurisdiction, the power
company or electric utility, and this installation manual.
In the absence of local code requirements, follow the
regulations set forth in the latest edition of The National
Electric Code, NFPA 70. This is available from the
following:
National Fire Protection Association
1 Batterymarch Park
Quincy, MA 02269
American National Standards Institute
1430 Broadway
New York, NY 10018
Check your phone listings for the local authorities having
jurisdiction over your installation.
Consumer Responsibilities
This manual has been prepared to acquaint you with the
installation, operation and maintenance of your electric heat
pump water heater and to provide important safety information
in these areas.
We urge you to read all of the instructions thoroughly before
attempting the installation or operation of this water heater.
This manual should be kept for future reference.
The manufacturer of this water heater will not be liable for any
damages caused by failure to comply with the installation and
operating instructions outlined in this manual.
If you lack the necessary skills required to properly install this
water heater or you have difficulty following the directions, you
should not proceed but have a qualified person perform the
installation of this water heater.
Examples of a qualified person include: licensed plumbers,
authorized electric company personnel, and authorized
service personnel.
Massachusetts code requires this water heater to be installed
in accordance with Massachusetts 248-CMR 2.00: State
Plumbing Code and 248-CMR 5.00.
A data plate identifying your water heater can be found
adjacent to the upper element door. When referring to your
water heater always have the information listed on the data
plate readily available, to include the model and serial number.
Retain your original receipt as proof of purchase.
Basic Operation Fundamentals
The Heat Pump Water Heater (HPWH) is an integrated
heat pump water heater unit, having an 850 watt
compressor and external coil heat exchanger with backup
electric elements (See Figure 1). When in Efficiency Mode
the heat pump draws heat from the ambient air in the room
and transfers it to the water in the tank through the coil
heat exchanger. While in Electric Mode the water heater
functions like a standard electric water heater, relying on
the electric elements to heat the water. A Hybrid Mode is
available that relies primarily on the heat pump to heat
the water while the electric elements only function during
high demand periods. (See “Adjusting the User Interface
Module/ Operational Mode” section). The more often
the unit operates using the heat pump, rather than the
elements, the more efficient the unit will be.
The 80-gallon tank capacity of this water heater is intended
to take optimal advantage of the heat pump’s capability to
heat water for large families or those having higher than
normal hot water requirements. This high capacity will
enable the unit to operate in the maximum efficiency mode
more often than other models having lower capacity.
The HPWH uses about half the electricity of a comparably
sized conventional electric water heater when operating
in the Efficiency Mode, and provides up to ½ ton cooling
capacity and dehumidification. It is designed for indoor,
residential applications for installation in a basement,
garage or utility room (See “Location Requirements”
section).
Ambient Air Cool/Dehumidified Air
Heat Exchanger
(Heat Transfer Coils)
Upper Element
(4500 Watt)
Lower Element
(2000 Watt)
Water Tank
Jacket
Figure 1
Heat Pump Water Heater Basic Operation
Heat Pump
(Transfers heat
from ambient
air to Heat
Exchanger)
Unpacking the Water Heater
WARNING
Excessive Weight Hazard
Use two or more people to move and install
water heater.
Failure to do so can result in back or
other injury.
Removing Packaging Materials
IMPORTANT: Do not remove, cover or deface any
permanent instructions, labels, or the data label from either
the outside of the water heater or on the inside of water
heater panels.

4
Figure 3
Residential Garage
Installation
Vehicle
Stop
Drain
Drain
Pan
NOTE: The water heater shall be located so it is not subject
to physical damage by moving vehicles or area flooding.
State of California
NOTE: The water heater must be braced, anchored, or
strapped to avoid moving during an earthquake. Contact
local utilities for code requirements in your area, visit
http://www.dsa.dgs.ca.gov, or call 1-916-445-8100 and
request instructions.
IMPORTANT: The water heater should be located in an
area where leakage of the tank, connections, condensate
lines or condensate will not result in damage to the area
adjacent to the water heater or to lower floors of the
structure. Due to the normal corrosive action of the water,
the tank will eventually leak after an extended period of
time. Also, any external plumbing leak, including those
from improper installation, may cause early failure of the
tank due to corrosion if not repaired. If the homeowner is
uncomfortable with making the repair a qualified person
should be contacted. A suitable metal drain pan should be
installed under the water heater as shown below, to help
protect the property from damage which may occur from
condensate formation or leaks in the piping connections
or tank. The pan must limit the water level to a maximum
depth of 2-1/2 inches and be two inches wider than the
heater and piped to an adequate drain. Locate the water
heater near a suitable indoor drain. Outside drains are
subject to freezing temperatures which can obstruct
the drain line. The piping should be at least 3/4” ID and
sloped for proper drainage. Under no circumstance will the
manufacturer or seller of this water heater be held liable
for any water damage which is caused by your failure to
follow these instructions.
METAL
DRAIN
PAN
AT LEAST 2” GREATER THAN THE
DIAMETER OF THE WATER HEATER.
PIPED TO AN
ADEQUATE DRAIN
The water heater must NOT be placed on its side. It•
should be transported and stored in an upright position.
Remove exterior packaging and place installation•
components aside.
Inspect all parts for damage prior to installation and•
start-up.
Completely read all instructions before attempting to•
assemble and install this product.
After installation, dispose of/recycle all packaging•
materials.
Location Requirements
Site location
Select a location near the center of the water piping system.
The unit must be installed indoors and in a vertical position
on a level surface. The flooring beneath the water heater
must be able to support the weight of the water heater when
filled with water (967 lbs. full).
IMPORTANT: The water heater must be located in a space
750 cubic feet or larger, and must have unrestricted airflow.
As an example, a room that has an 8 foot tall ceiling and is
10 feet long by 9-1/2 feet wide would contain 760 cubic feet.
NOTE: For optimal efficiency and serviceability, the
following clearances should be maintained: 3 feet on the air
inlet side, 5 feet. on the air outlet side, 6 inches in the back,
and 2 feet in the front.
The water heater should be located in an area not
subject to freezing temperatures. Water heaters located
in unconditioned spaces (i.e., garages, basements, etc.)
may require the water piping, condensate piping, and drain
piping to be insulated to shelter against freezing. The drain
and controls must be easily accessible for operation and
service.
The site location must be free from any corrosive elements
in the atmosphere such as sulfur, fluorine, and chlorine.
These elements are found in aerosol sprays, detergents,
bleaches, cleaning solvents, air fresheners, paint, and
varnish removers, refrigerants, and many other commercial
and household products. In addition, excessive dust and
lint may affect the operation of the unit (See “Cleaning the
Filter” section).
The ambient air temperature must also be considered
when installing this unit. In Efficiency Mode the ambient air
temperature must be above 45°F and below 109°F. If the
ambient air temperature falls outside these upper and lower
limits the electrical elements will activate to meet the hot
water demand and the heat pump does not operate.
NOTE: Local codes and requirements in your area may
require the installation of your water heater be accomplished
in a way that the bottom element is elevated from the
floor at least 18 inches. Ensure that a platform capable of
supporting the combined weight of the water heater and
water (967-pounds) is used.
Figure 2
Metal Drain Pan
Installation

5
Water System Piping
Piping, fittings, and valves should be installed according to
the installation drawing (Figure 4). If the indoor installation
area is subject to freezing temperatures, the water piping
must be properly insulated.
Water supply pressure should be 50-60 PSIG and not
exceed the maximum 80 PSIG. If the supply line pressure
exceeds 80 PSIG, a pressure reducing valve (PRV) with
a bypass should be installed in the cold water supply line.
This should be placed on the supply to the entire house in
order to maintain equal hot and cold water pressures.
IMPORTANT:
• Heat must not be applied to the water fittings on
the heater as they may contain nonmetallic parts. If
solder connections are used, solder the pipe to the
adapter before attaching the adapter to the hot and
cold water fittings.
• Always use a good grade of joint compound and be
certain that all fittings are tight.
IMPORTANT: DO NOT over apply joint compound.
Piping Installation
Install the water piping and fittings as shown in Figure1.
4. Connect the cold water supply (3/4” NPT) to the
fitting marked “Cold”. Connect the hot water supply
(3/4” NPT) to the fitting marked “Hot”.
The installation of unions in both the hot and cold2.
water supply lines are recommended for ease of
removing the water heater for service or replacement.
Some local codes may require, and the manufacturer3.
of this water heater recommends, installing a mixing
valve or an anti-scald device in the domestic hot water
line as shown in Figure 4. These valves reduce the
point-of-use temperature of the hot water by mixing
cold and hot water and are readily available. Contact
a licensed plumber or the local plumbing authority for
more information.
Some local codes may require, and the manufacturer4.
of this water heater recommends, installing a pressure
reducing valve (PRV) in the cold water inlet line where
it enters the residence as shown in Figure 4.
If installing the water heater in a closed water system,5.
install an expansion tank in the cold water line as
specified under “Closed System/Thermal Expansion.”
Install a shut off valve in the cold water inlet line. It6.
should be located close to the water heater and be
easily accessible. Know the location of this valve and
how to shut off the water to the heater.
Install a discharge line from the temperature and7.
pressure relief valve in the opening marked “T & P
RELIEF VALVE”. See Figure 5 and the “Temperature
and Pressure Relief Valve” section.)
After piping has been properly connected to the water8.
heater, open the nearest hot water faucet. Then open
the cold water shut off valve and allow the tank to
completely fill with water. To purge the lines of any
excess air and sediment, keep the hot water faucet
open for 3 minutes after a constant flow of water is
obtained. Close the faucet and check all connections
for leaks.
Cold Water
Inlet Valve
Cold Water
Inlet
Whole House Pressure Reducing
Valve (PRV) should be installed
where the water supply enters
the residence.
In a closed system, use a
thermal expansion tank.
See “Closed System/
Thermal Expansion”
section.
Cold Water Outlet
Shut-off Valve
(Cold)
Tempered Water to Fixtures
Untempered Water Outlet
Vacuum Relief Valve
Mixing Valve (Optional) - Follow the
Mixing Valve’s Manufacturer’s Installation
Instructions. (Set to 120° F)
6” Maximum
Air Gap
Metal Drain Pan 2 1/2”
Depth Maximum and
2 Inches wider than
the water heater.
Discharge Pipe
(Do Not Cap or Plug)
Temperature and
Pressure Relief Valve
Union
Shut-off Valve (Hot)
Drain Line 3/4”
ID Minimum Drain
Condensate Drain Lines*
Massachusetts: Install a vacuum relief in cold
water line per section 19 MGL 142.
Figure 4
Water Piping Installation
with Mixing Valve
* If an adequate drain is not available for the condensate drain lines then a condensate pump should be used. DO NOT discharge the condensate drain
lines into the metal drain pan.
Union
Hot
(Outlet)
Cold
(Inlet)
Heat Trap - The top of the heat trap
must be higher than the storage tank
of the water heater.