WaterFurnace NEW050 Installation Manual

504W11 Geothermal Hydronic Heat Pump

e

3 to 5 Tons NEW Series

Installation Information

Water Piping Connections

Electrical Data

Startup Procedures

Preventive Maintenance

5 Series OptiHeat Installation Manual

5 S

IM2508WN 02/19

Table of Contents

Model Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

General Installation Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Field Connected Water Piping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Hydronic Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

External Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Accessories and Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Wiring Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Unit Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Aurora Base Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Reference Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Legend and Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Water Pressure Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Pressure Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Operating Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Flow Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Heating & Cooling Operating Envelope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Thermistor and Compressor Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Operating Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Antifreeze Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Troubleshooting Guideline for Refrigerant Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

HR Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

HE Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Heating and Cooling Cycle Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Troubleshooting Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

Service Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Revision Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

N E W

NEW

050 * 1 0 R C

34-67 8 91011

Model

N – 5 Series Hy dronic

Heat Pump

Compressor Type

E – Vapor Injection

Cabinet Configuration

W – Water-to-Water

Unit Capacity

040, 050, 066

Vintag e

* - Factory Use Only

Voltag e

1 – 208-230/60/1

Hot Wate r Op tio n

0 – No H ot Wa ter G ene ra ti on

IntelliStart®

N – None

A – IntelliStart

Controls Option

B – Aurora

TM

Advanced Controls

D – AuroraTM Performanc e1 & Refrigeration

Future Option

0 – Standar d

Future Option

S – Standard

Future Option

S – Standard

Water Coil Option

C – Copper

Reversible Option

R – Reversible

H – Heating Only

Rev.: A 9/27/18 ADL

S

12

21

S 0 B N

y

H

um p

y

Inj

ig

o

W

y

n

o

er

n

13 14 15

16

Model Nomenclature

ries

dro

t P

sor T

or

onf

t

cit

ry Use Onl

ic

e

ctio

rati

n

t

NOTE: 1 – Flow meter for Performance Refrigeration option is shipped inside the unit and must be externally field installed.

Voltage

208-230/60/1

● - Voltage available in this size

040 050 066

●● ● ●

●● - Voltage and soft start available in this size

NEW

All 5 Series product safety listed under UL1995 thru ETL and performance listed
with AHRI in accordance with standard 13256-1. The 5 Series is also ENERGY STAR
rated.

®

4

General Installation Information

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Safety Considerations

Installing and servicing air conditioning and heating
equipment can be hazardous due to system pressure and
electrical components. Only trained and qualified service
personnel should install, repair or service heating and air
conditioning equipment. When working on heating and
air conditioning equipment, observe precautions in the
literature, tags and labels attached to the unit and other
safety precautions that may apply.

Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for brazing operations. Have
fire extinguisher available for all brazing operations.

NOTE: Before installing, check voltage of unit(s) to ensure
proper voltage.

WARNING: Before performing service or
maintenance operations on the system, turn off
main power switches to the unit. Electrical shock
could cause serious personal injury.

WARNING: This heat pump is capable of
producing hot water up to 150°F. All exposed
piping surfaces shall be insulated to prevent
serious personal injury that can occur from
touching water piping.

Unit Location

Provide sufficient room to make water and electrical
connections. If the unit is located in a confined space,
provisions must be made for unit servicing. Locate the
unit in an indoor area that allows easy removal of the
access panels and has enough space for service personnel
to perform maintenance or repair. These units are not
approved for outdoor installation and, therefore, must be
installed inside the structure being conditioned. Do not
locate units in areas subject to freezing conditions.

WARNING: Do not store or install units in
corrosive environments or in locations subject
to temperature or humidity extremes (e.g. attics,
garages, rooftops, etc.). Corrosive conditions and
high temperature or humidity can significantly
reduce performance, reliability, and service life.

Mounting Units

Prior to setting the unit in place, remove and discard the
compressor hold down shipping bolt located at the front
of each compressor mounting bracket. Units should be
mounted level on a vibration absorbing pad slightly larger
than the base to provide isolation between the unit and
the floor. It is not necessary to anchor the unit to the
floor. Allow access to the front, back, top and side access
panels for servicing.

Application

Units are not intended for heating domestic (potable) water
or swimming pools by direct coupling. If used for this type
of application, a secondary heat exchanger must be used.

Moving and Storage

Move units in the normal “Up” orientation as indicated by
the labels on the unit packaging. When the equipment
is received, all items should be carefully checked against
the bill of lading to ensure that all crates and cartons
have been received in good condition. Examine units for
shipping damage, removing unit packaging if necessary
to properly inspect unit. Units in question should also
be internally inspected. If any damage is observed, the
carrier should make the proper notation on delivery receipt
acknowledging the damage. Units are to be stored in a
location that provides adequate protection from dirt, debris
and moisture.

WARNING: To avoid equipment damage, do not
leave the system filled in a building without heat
during cold weather, unless adequate freeze
protection levels of antifreeze are used. Heat
exchangers do not fully drain and will freeze
unless protected, causing permanent damage.

Vibration Pad Mounting

5

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Field Connected Water Piping

General

Each unit is equipped with captive FPT water connections
to eliminate ‘egg-shaping’ from use of a backup wrench.
For making the water connections to the unit, a Teflon tape
thread sealant is recommended to minimize internal fouling
of the piping. Do not over tighten connections. All supply and
return water piping should be insulated to prevent excess
condensation from forming on the water lines.

NOTE: Units are factory run-tested using propylene
glycol. Prior to connecting piping to unit, thoroughly flush
heat exchangers.

The piping installation should provide service personnel with
the ability to measure water temperatures and pressures.
The water lines should be routed so as not to interfere with
access to the unit. The use of a short length of high pressure
hose with a swivel type fitting may simplify the connections
and prevent vibration. Optional stainless steel hose kits are
available as an accessory item.

Before final connection to the unit, the supply and return
hose kits must be connected, and the system flushed
to remove dirt, piping chips and other foreign material.
Normally, a combination balancing and close-off (ball) valve
is installed at the return, and a rated gate or ball valve is
installed at the supply. The return valve can be adjusted to
obtain the proper water flow. The valves allow the unit to be
removed for servicing.

Water Quality

It is the responsibility of the system designer and installing
contractor to ensure that acceptable water quality is
present and that all applicable codes have been met in
these installations. Failure to adhere to the guidelines in
the water quality table could result in loss of warranty.
In ground water situations where scaling could be heavy
or where biological growth such as iron bacteria will be
present, a closed loop system is recommended. The heat
exchanger coils in ground water systems may, over a period
of time, lose heat exchange capabilities due to a buildup
of mineral deposits inside. These can be cleaned, but only
by a qualified service mechanic, as special solutions and
pumping equipment are required. Hot water generator coils
can likewise become scaled and possibly plugged. In areas
with extremely hard water, the owner should be informed
that the heat exchanger may require occasional flushing.

Heat pumps with cupronickel heat exchangers are
recommended for open loop applications due to the
increased resistance to build-up and corrosion, along with
reduced wear caused by acid cleaning.

The proper water flow must be delivered to each unit
whenever the unit heats or cools. To assure proper flow,
the use of pressure/temperature ports is recommended
to determine the flow rate. These ports should be located
adjacent to the supply and return connections on the unit.
The proper flow rate cannot be accurately set without
measuring the water pressure drop through the refrigerant­to-water heat exchanger (See Pressure Drop Table for water
flow and pressure drop information). Normally about 3 GPM
flow rate per ton of cooling capacity (2.25 GPM per ton
minimum) is needed. Both source as well as load fluid piping
must be at least as large as the unit connections on the heat
pump (larger on long runs).

Never use flexible hoses of a smaller inside diameter than
that of the water connection on the unit and limit hose length
to 10 ft. per connection. Check carefully for water leaks.

CAUTION: Water piping exposed to outside
temperature may be subject to freezing.

6

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Field Connected Water Piping cont.

Material Copper 90/10 Cupronickel 316 Stainless Steel

pH Acidity/Alkalinity

Scaling

Corrosion

Iron Fouling

(Biological Growth)

Erosion

NOTES: Grains = ppm divided by 17

mg/L is equivalent to ppm

Calcium and

Magnesium Carbonate

Hydrogen Sulfide

Chlorine Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm

Chlorides Less than 20 ppm Less than 125 ppm Less than 300 ppm

Carbon Dioxide Less than 50 ppm 10 - 50 ppm 10 - 50 ppm

Ammonia Less than 2 ppm Less than 2 ppm Less than 20 ppm

Ammonia Chloride Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm

Ammonia Nitrate Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm

Ammonia Hydroxide Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm

Ammonia Sulfate Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm

Total Dissolved Solids (TDS) Less than 1000 ppm 1000 - 1500 ppm 1000 - 1500 ppm

LSI Index +0.5 to -0.5 +0.5 to -0.5 +0.5 to -0.5

Iron, FE

Bacterial Iron Potential

Iron Oxide

Suspended Solids

Threshold Velocity

(Fresh Water)

Less than 0.5 ppm (rotten egg

Sulfates Less than 125 ppm Less than 125 ppm Less than 200 ppm

2

+ (Ferrous)

smell appears at 0.5 ppm)

Less than 1 ppm, above this

level deposition will occur

Less than 10 ppm and filtered

for max. of 600 mic

7 - 9 7 - 9 7 - 9

(Total Hardness)

less than 350 ppm

< 0.2 ppm < 0.2 ppm < 0.2 ppm

ron size

< 6 ft/sec < 6 ft/sec < 6 ft/sec

(Total Hardness)

less than 350 ppm

10 - 50 ppm Less than 1 ppm

Less than 1 ppm, above this

level deposition will occur

Less than 10 ppm and filtered

for max. of 600 micron size

(Total Hardness)

less than 350 ppm

Less than 1 ppm, above this

level deposition will occur

Less than 10 ppm and filtered

for max. of 600 micron size

2/22/12

Water Treatment

Do not use untreated or improperly treated water.
Equipment damage may occur. The use of improperly
treated or untreated water in this equipment may result in
scaling, erosion, corrosion, algae or slime. Purchase of a pre­mix antifreeze could significantly improve system reliability
if the water quality is controlled and there are additives in
the mixture to inhibit corrosion. There are many examples
of such fluids on the market today such as Environol™ 1000
(pre-mix ethanol), and others. The services of a qualified
water treatment specialist should be engaged to determine
what treatment, if any, is required. The product warranty
specifically excludes liability for corrosion, erosion or
deterioration of equipment.

The heat exchangers and water lines in the units are copper
or cupronickel tube. There may be other materials in the
buildings piping system that the designer may need to take
into consideration when deciding the parameters of the
water quality. If antifreeze or water treatment solution is
to be used, the designer should confirm it does not have a
detrimental effect on the materials in the system

.

Contaminated Water

In applications where the water quality cannot be held to
prescribed limits, the use of a secondary or intermediate
heat exchanger is recommended to separate the unit fro
the contaminated water. The table above outlines the
water quality guidelines for unit heat exchangers. If these
conditions are exceeded, a secondary heat exchanger is
required. Failure to supply a secondary heat exchanger
where needed will result in a warranty exclusion for primary
heat exchanger corrosion or failure.

WARNING: Must have intermediate heat exchanger
when used in pool and spa applications.

7

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Field Connected Water Piping cont.

Figure 1a: Open Loop Solenoid Valve Connection Option

Open Loop Well Water Systems

Always maintain water pressure in the heat exchanger by
placing water control valves at the outlet of the unit. Use
a closed bladder type expansion tank to minimize mineral
deposits. Ensure proper water flow through the unit by
checking pressure drop across the heat exchanger and
comparing it to the figures in the pressure drop table.
Normally, about 2 GPM flow rate per ton of cooling capacity
is needed in open loop systems, (1.5 GPM per ton minimum if
entering source temperature is above 50°F [10°C].

Some water control valves draw their power directly from
the unit’s 24V transformer and can overload and possibly
burn out the transformer. Check total VA draw of the water
valve(s) and ensure it is under 40 VA.

Typical quick operating external 24V water solenoid valve
(type PPV100 or BPV100) wiring.

SV

Solenoid

Valve

C
R

Acc Com
Acc NC
Acc NO

ABC Board

P1

1
2

P2

3

Discharge water from a heat pump can be disposed of in
various ways depending on local building codes (i.e. recharge
well, storm sewer, drain field, adjacent stream or pond,
etc.). Most local codes restrict the use of sanitary sewer for
disposal. Consult your local building and zoning departments
to ensure compliance in your area.

Typical Open Loop Installation

NOTE: SW2-4 and SW2-5 should be “OFF” to cycle with
the compressor.

Figure 1b: Open Loop Solenoid Valve Connection Option

Typical slow operating external 24V water solenoid valve
(type V100FPT) wiring.

Orange(29)

C
R

Black/

C

W/Y

White(31)

Blue(30)

Acc Com

ACC NC

Acc NO

V Valve ABC Board

NOTE: SW2-4 should be “ON” and SW2-5 should be “OFF”
when using a slow opening (V100FPT) water valve.

Rubber Bladder

Expansion Tank

Line Voltage
Disconnect

Load Liquid

Connections

(to isolate solenoid

Shut-off Valve

valve while acid

flushing)

Flow Regulator Valve

Solenoid

Valve

Boiler Drains for
HX Flushing

P/T Plugs

Vibration Absorbing
Mesh or Air Pad

8

Water Out

Water In

Shut-off
Valve

NOTE: Valves and boiler drains must be installed
so the heat exchanger can be acid flushed.

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

VS

GN D

24 VA C

0-10DC

1
2

3

R

C

ABC BOAR D

AXB BOARD

MODULATING VALVE

1

2

Red

White

Green

NO TE: 13

Field Connected Water Piping cont.

Modulating Water Valve Setup

When using a modulating water valve kit (4MWVK or
5MWVK) the use of an AID Tool will be necessary to adjust
minimum and maximum flow rates. The factory default is
minimum = 70% and maximum = 100% flow levels. Since the

OptiHeat is a single speed unit, the minimum and maximum
must be set at the same level. See the Variable Speed Pump

Setup and Modulating Water Valve Setup instructions within
the Unit Startup section which is located in the back of this
manual. Refer to the Flow Rate section of this manual to

ensure that there is adequate flow for the heat pump.

Modulating Water Valve Connection Option

Typical 0-10VDC modulating water valve.

Earth Coupled Systems with Flow Center

NOTE: For closed loop systems with antifreeze protection,

set SW2-1 to the “LOOP” (15°F) position. (Refer to the DIP
Switch Settings table in the Aurora Control section.)

Once piping is completed between the unit, pumps and the
ground loop (see figure below), final purging and charging
of the loop is required. A flush cart (or a 1.5 HP pump
minimum) is needed to achieve adequate flow velocity
in the loop to purge air and dirt particles from the loop
itself. Antifreeze solution is used in most areas to prevent
freezing. Flush the system adequately to remove as much
air as possible then pressurize the loop to a static pressure
of 40-50 psi (summer) or 50-75 psi (winter). This is
normally adequate for good system operation. Loop static
pressure will fluctuate with the seasons. Pressures will be
higher in the winter months than during the cooling season.
This fluctuation is normal and should be considered when
initially charging the system.

After pressurization, be sure to turn the venting (burping)
screw in the center of the pump two (2) turns open (water
will drip out), wait until all air is purged from the pump,
then tighten the plug. Ensure that the flow center provides
adequate flow through the unit by checking pressure drop
across the heat exchanger and by comparing it to the figures
shown in the Pressure Drop tables. Usually 3 GPM/ton or
minimum 2.25 GPM/ton of cooling capacity is needed in
closed loop earth-coupled applications.

Typical Closed Loop Earth Coupled Installation

Earth Coupled Loop

Piping with Insulation

Line Voltage
Disconnect

Unit Connector Kits

with Insulation

P/T Plugs

Load Liquid

Connections

Vibration Absorbing
Mesh or Air Pad

9

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Field Connected Water Piping cont.

Multiple Units on One Flow Center

NOTE: This feature is only available in the Aurora Advanced

Control package (AXB board), NOT the Aurora Base Control
(ABC).

When two units are connected to one loop pumping system,
pump control is automatically achieved by connecting the
SL terminals on connector P2 in both units with 2-wire
thermostat wire. These terminals are polarity dependant (see
Figure 2). The loop pump(s) may be powered from either
unit, whichever is more convenient. If either unit calls, the loop
pump(s) will automatically start. The use of two units on one
flow center is generally limited to a total of 20 gpm capacity.
It is recommended that water solenoid valves be installed
on heat pumps that share a flow center. This is to allow
water flow through only the heat pump that has a demand.
Circulating fluid through a heat exchanger of a system that is
not operating could be detrimental to the long term reliability
of the compressor.

Figure 2: Primary/Secondary Hook-up

5 Series to

Electromechanical Units

5 Series Unit #1
with AXB Board

C

To Electromechanical Unit

S

OUTIN C C

VSSLOSLI

With pump
wired to Unit 1

With pump
wired to
Unit 2

5 Series to

5 Series Units

5 Series Unit #1

with AXB Board

OUTIN C C

OUTIN C C

5 Series Unit #2
with AXB Board

VSSLOSLI

VSSLOSLI

5 Series to

Envision Units

5 Series Unit #1

with AXB Board

With pump
wired to
Unit 1

Shut

CC

Down

Envision Unit #2

OUTIN C C

VSSLOSLI

With pump
wired to
Unit 2

SL1InSL1

Out

Variable Speed Pump Setup

When using a variable speed pump flow center (FCV1-GL,
FCV2-GL, FCV1-GLNP or FCV2-GLNP) the use of an AID
Tool will be necessary to adjust minimum and maximum flow
rates. The factory default is minimum = 75% and maximum
100% flow levels. Since the OptiHeat is a single speed unit,
the minimum and maximum must be set at the same level.
See the Variable Speed Pump Setup and Modulating Water
Valve Setup instructions within the Unit Startup section
which is located in the back of this manual. Refer to the Flow
Rate section of this manual to ensure that there is adequate
flow for the heat pump.

10

Hydronic Section

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

General guidelines are shown below for component
selection and design/installation criteria for the piping
system. Local codes supersede any recommendations in
this manual.

Shut Off/Flow Regulation Valves

Use full port ball valves or gate valves for component
isolation. If valves are going to be used frequently, ball
valves are recommended. Globe valves are designed for flow
regulation. Always install globe valves in the correct direction
(fluid should enter through the lower body chamber).

Check valves

Swing check valves must be installed in the horizontal
position with the bonnet of the valve upright. Spring check
valves can be mounted in any position. A flow check valve
is required to prevent thermo-siphoning (or gravity flow)
when the circulator pump is off or when there are two
circulators on the same system.

Storage (Buffer) Tank

A buffer tank is required for all hydronic heating systems

using OptiHeat heat pumps. The tank should be sized
to provide 2 gallons of storage capacity for every one
thousand Btuh’s of nominal heat pump capacity.

Pressure Relief Valve

Most codes require the use of a pressure relief valve if a
closed loop heat source can be isolated by valves. Even
if local code does not require this device, WaterFurnace
recommends its installation. If the pressure relief valve in
the buffer tank is not already rated at 30 psi (207 kPa)
maximum pressure, one must be installed. The pressure
relief valve should be tested at start up for operation. Note
that the waste pipe must be at least the same diameter
as the valve outlet (never reduce), and valves may not be
added to this pipe. The bottom of the pipe must terminate
at least 6” (15 cm) above the floor. If the piping is connected
to a drain, there must be an air gap.

Backflow Prevention Check Valves

Most codes require backflow prevention check valves.
Note that a single check valve is not equal to a backflow
prevention check valve. Even if local code does not require
this device, WaterFurnace recommends its installation. This
is particularly important if the system will use antifreeze.

0 psi (0 kPa), potentially causing pumps(s) failure. A valve
should be installed on each side of the pressure reducing
valve for servicing. Both valves should have tags reading

“Do not shut this valve under normal operation – service

valve only.”

Expansion Tanks

Expansion tanks are required on hydronic systems to help
absorb the pressure swings as the temperature in the
system fluctuates.

Elbows/Tees

Long radius elbows or two 45° elbows will lower pressure
drop. Standard tees have a greater restriction on the “T”
portion than tees designed with angled outlet ports.

Antifreeze

Antifreeze is required if any of the piping system is located

in areas subject to freezing.

Dielectric Unions

Dielectric unions are recommended whenever connecting
two dissimilar metals together to prevent electro-galvanic
corrosion.

When using the various types of hydronic heat distribution

systems, the temperature limits of the geothermal system
must be a major consideration. In new construction, the
distribution system can easily be designed with the
temperature limits in mind. In retrofits, care must be
taken to address the operating temperature limits of the
existing distribution system. The maximum storage tank
temperature for the OptiHeat is 150°F (65°C). Typical in
floor radiant systems require much lower temperatures,
typically 100°-115°F, which is ideal for the OptiHeat.

On load pumps open the screw 2 turns only in the end of the

pump motor (if Grundfos
air to be discharged and to ensure the motor housing has been
flooded.

®

pumps are used) to allow trapped

Pressure Reducing Valves or Feed Water Valves

This valve lowers the pressure from the make-up water line

to the system. Most are adjustable and directional. A “fast
fill” valve is required for initial filling of the system. Some
have screens, which must be cleaned after the initial filling.
If there is a restriction in the screen, the system could go to

11

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Hydronic Section cont.

If using a Geothermal Storage tank there will be two red
wires exiting out of the top of the tank. These red wries
extend internally down to the thermistor/tank thermostat
section of the tank. Remove the bottom tank cover to expose
the red wires as well as the yellow tank thermistor wires.

HydroZone

If using HydroZone control, connect the two red wires to
the two yellow wires using wire nuts. Next, connect the two
red wires from the top of the Geothermal Storage tank to
“TS” and “GND” on the HydroZone. The “OAT” and “GND”
terminals on the HydroZone are used for an outdoor air
sensor.

HydroStat

If using HydroStat control, connect the two red wires to the
yellow wires using wire nuts. Next, connect the two red wires
from the top of the Geothermal Storage tank to “TS” and
“GND” on the HydroStat. The “OAT” and “GND” terminals
on the HydroStat are used to connect the controller to the
ELWT (Entering Load Water Temperature) well point sensor.
This sensor is located on the load side entering water line
inside the unit.

For other field installed controllers, these two red wires
will need wired to the appropriate sensor input terminals.
Another option for connection is to connect the thermostat
on the Geothermal Storage tank directly to “R” and “Y1” on
the ABC board.

Adequate rate of flow (GPM) is very important to system
performance and long term reliability. Follow the guidelines
for recommended flow in the recommendations table.

WaterFurnace Geothermal Storage Tank Thermostat
and Thermistor

Thermostat

HydroZone

or HydroStat

30 psi

RELIEF VALVE

Back Flow Preventer /

Pressure Relief Valve

Dielectric

Unions

Dielectric

Unions

NOTES:
* A 30 psi pressure relief valve (Part No: SRV30) should be used in

hydronic applications.
** Vent valve or P/T port at highest point in return line prior to ball valve.

Pressure

Gauge

GEO

STORAGE

TANK

1-1/2 in.
FPT

Dip Tube

Ball Valve

Expansion

Tank

Air

Vent

Air

Separator

Ball Valve

LOAD PUMP

HYDRONIC

LOAD

Source OUT

P/T PortsP/T Ports

Source IN

NEW Series

12

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

External Control

An external controller is necessary for operation. For water storage tank set point control the HydroStat HSC, HZC, and HZ0

were designed specifically for our Geo-Storage Tanks. A field supplied aquastat may also be used as the external control
to the heat pump. If zoning is required, the Hydrologic Zone Panels and Control system can provide up to eight zones of
closed loop hydronic heating and cooling.

HydroStat (HSC) features:

• Communicating Controller

• Pump Sampling

• 2 1/2” x 2 1/2” LCD display and five push buttons serve as the human interface

• Controls and regulates water tank temperature

• Fahrenheit or Celsius

• Symphony Compatibility - without HydroStat the tank temperature won’t be displayed on Symphony.

• Single Stage

HydroZone (HZC) features:

• 2 1/2” x 2 1/2” LCD display and five push buttons serve as the human interface

• Controls and regulates water tank temperature

• Fahrenheit or Celsius

• Outdoor reset

• Warm weather shutdown

• Single Stage

HydroZone (HZO) features:

• HZC mounted on 7.5” x 7.5” x 3.25” electrical box

• HydroZone relay board

• 2 1/2” x 2 1/2” LCD display and five push buttons serve as the human interface

• Controls and regulates water tank temperature

• Fahrenheit or Celsius

• Outdoor reset

• Warm weather shutdown

• Staging (up to 4 stages)

• Lead/Lag (when staging)

HydroLogic features:

• Operates radiant floor heating

• Operates hydronic fan coil heating and cooling

• 4 zones expandable to 8 zones

• Communicating 2 wire controls

• Controls 2 stages of compressors with rotation

• Controls backup heat source

• Intelligent heat/cool switchover

• Fahrenheit or Celsius

• Outdoor reset

• Indoor temperature feedback

• Warm weather shutdown

13

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Accessories and Options

IntelliStart (Model 040 only)

IntelliStart is a single phase compressor soft starter which
reduces the normal start current (LRA) by 60-70%. It should
be used in applications that require low starting amps,
reduced compressor start-up noise, off-grid, and improved
start-up behavior. IntelliStart is available as a factory
installed option or a field installed kit. IntelliStart is available
on 208-230/60/1 voltage.

Water Connection Kits (Field Installed)

Water connection kits are available to facilitate loop side and
load side water connections.

• MA4FPT - Forged brass 1" MPT x 1" FPT square street elbow
with P/T plug for NEW040 water side connections

• MA5FPT - Forged brass 1.25" MPT x 1.25" FPT square
street elbow with P/T plug for NEW050-NEW066 water
side connections

• WFI-HKM-100-24-MO - 1 inch x 24 inch stainless steel
braided hose kit

• WFI-HKM-125-24-MO - 1

1

⁄4 inch x 24 inch stainless steel

braided hose kit

Earth Loop Pump Kit (Field Installed)

A specially designed one or two-pump module provides all
liquid flow, fill and connection requirements for independent
single unit systems (230/60/1 only). The one-pump module
(FC1-FPT or FC1-GL) is capable of 25 feet of head at 12.0
GPM, while the two-pump module (FC2-FPT or FC1-GL) is
capable of 50 feet of head at 12.0 GPM.

Load-side Pump Kit (Field Installed)

Four (4) load pump kits are available to provide all liquid
flow requirements for independent single unit systems
(230/60/1 only). WaterFurnace part number 24S516-

10 (Grundfos UPS15-42RU) is a composite body pump.
EWPK2 (Grundfos UP26-99SF) is stainless steel body

pump. WaterFurnace part number EWPK1 and EWPK3
come with a cast iron body pump (Grundfos UP26-99F)
that can be used for hydronic heating applications.

Calculate the system pressure drop then refer to the
pump curves in figure 8 to select the proper pump. All
four (4) of the WaterFurnace pump kits can be used for
hydronic heating applications as long as they meet the
flow requirements. If the flow requirements are outside the
pump curve, an alternate pump will need to be obtained to
maintain the necessary flow.

• 24S516-10 - UPS15-42RU composite PPS,
sweat connection

• EWPK1 - UP26-99F cast iron volute, 1 inch FPT
flange connection

• EWPK2 - UP26-99SF Stainless Steel volute, 1 inch FPT
flange connection

• EWPK3 - UP26-99F cast iron volute, 1­flange connection

3

⁄4 inch union

1

⁄4 inch FPT

Figure 8: UPS15-42RU and UP26-99F Pump Curve

UPS15-42RU, and UP26-99F Single Pump Curve

Pump Curve - Single Pump

35

30

25

20

15

Feet of Head

10

5

0

0 5 10 15 20 25 30 35

26-99F Two Pump Curve

Pump Curve - Two Pumps

70

60

50

40

30

Feet of Head

20

10

0

0 5 10 15 20 25 30 35

GPM

GPM

UP26-99F (2 pumps)

UP26-99F
UPS15-42RU

NOTE: Never use piping smaller than 1 inch. Limit length of
pipe to 50 feet or less.

Type L Copper Pressure Loss

Ft of Hd per 100 ft

GPM 3/4 1 1-1/4 1-1/2 2

2
3
4
5
6
7
8

9
10
12
14
16
18
20
22
25
30
35
40
45
50

1.5

3.2

5.5 1.4

8.5 2.1

Type L Copper Tube

2.9 1.1

3.9 1.4

5.0 1.8

6.1 2.3 0.9

7.5 2.8 1.1

3.9 1.6

5.2 2.1

6.6 2.7

8.2 3.4

10.0 4.1 1.1

5.0 1.3

6.3 1.6

2.2

2.9

3.8

4.7

5.7

NOTE: Standard piping practice limits pressure drop to 4
feet of hd per 100 feet in 2 inch and larger pipe.

14

Accessories and Options cont.

5 SERIES OPTIHEAT 504W11 INSTALLATION MANUAL

Geo Storage Tank Dimensions

PRIMARY ANODE

3/4˝ HOT OUTLET

w/14˝ SECONDARY ANODE

HEIGHT

Optional “To Geo”

Connection Shipped with

1-1/2˝ Pipe Plug

Taped to Bottom of Packaging

From Geo

1˝ x 3˝ Nipple

39˝ - 80 Gallon

42˝ - 119 Gallon

Approx. 1˝

VALV E

35-3/4˝

DRAIN VALVE

T & P

°

3

0

3

8˝

DIAMETER

0

°

To Geo 59˝ Dip Tube
w/1˝ x 3˝ Nipple

COLD INLET

3/4˝

52˝ DIP TUBE

Red Wire attached
to Thermistor or Thermostat
for Top Exit

Element Location

Lower Sensor Thermistor
to be used by Hydrozone or HydroStat Controllers

Optional “From Geo” Connection
Shipped with 1-1/2˝ Pipe Plug Installed

5-1/4˝

Lower Thermostat to be used
with Aurora Base Control Board

MODEL

NUMBER

GEO-STORAGE-80*

GEO-STORAGE-120**

* 040 Only
** 050 & 066 Only

GALLON

CAPACITY

80 4500 1 16 63-1/4 24 204

119 4500 1 16 63-1/4 28 311

ELEMENT

WATTAGE

(240 VOLT)

NUMBER

OF

ELEMENTS

R

VALUE

DIMENSIONS IN INCHES APPROX.

HEIGHT DIAMETER

15

SHIPPING

WEIGHT (lbs.)