Lochinvar AQUAS APN400 User manual

AQUAS POOL PACKAGE INSTALLATION INSTRUCTIONS
FOR MODELS: APN400 - 850
100326095_2000582397_Rev A
The AQUAS pool package system is a high efficiency
commercial condensing boiler, pre-piped package system
from the factory to an indirect heat exchanger. This pool
heater is a low temperature operating system designed to
take advantage of the stainless steel heat exchanger and
condensing operating temperatures to ensure the highest
efficiency possible. The AQUAS is designed around a
predetermined flow set by the manufacturer between the
boiler and the indirect heat exchanger. The AQUAS operates
off the pool system pump itself which will continually supply
water to the indirect heat exchanger. This means there is no
need to purchase a dedicated circulator to deliver water to
this package system.
AIR INLET
CONNECTION
GAS INLET
RELIEF
VALVE
T&P
GAUGE
FLOW
SWITCH
EXPANSION
TANK
SKID MOUNTED
ON FRAME
TITANIUM
HEAT EXCHANGER
FLUE
CONNECTION
DIR #2000546267 01
Figure 1 Component Location
AQUAS Pool Package
TABLE A
MODEL
RECOMMENDED
SYSTEM
WATER FLOW
CONNECTION SIZE
400 52 GPM 2"
500 65 GPM 2"
600 78 GPM 2"
725 94 GPM 2"
850 90 GPM 2"
Piping
Pool / spa connections to the indirect heat exchanger are SCH 80
CPVC glue fittings. The connections from the field loop to the
heat exchanger may be done in CPVC or PVC pipe as follows:
• Use a cement that is rated for PVC/CPVC piping.
• To make the connection, apply glue to both the CPVC flange
and the section of pipe.
• Insert the pipe into the flange until it reaches the bottom of
the flange.
• Turn the pipe a half turn in the socket to ensure that a proper
seal is made.
Pool water is designed to flow from bottom to top standing in
front of the boiler. The field installed sensor is to be on the inlet
of the heat exchanger.
The supply and return water piping to the indirect heat exchanger
shall be no smaller than 2" for all models.
Throttling Valve
A T of 15°F - 20°F across the indirect heat exchanger is
recommended. Throttling valves are used to set the flow through
the indirect heat exchanger (standard gate valves are acceptable).
Installation Instructions
To achieve the optimum operating efficiency of your AQUAS
it is recommended that you keep the pool water flow of each
appliance within plus or minus five gallons per minute
of the recommended flow as stated in Table A. Low flow
through the indirect heat exchanger will result in elevated
temperatures supplied to the pool.
RECOMMENDED CLEARANCES:
BOILER - SEE FTXL I & O MANUAL
INDIRECT HEX - ALLOW 18" FOR SERVICE ON ALL SIDES

Apply a small amount of a high quality RTV silicone sealant to
the threads to prevent leaks and install the limit into the threaded
opening in the pipe. Install the limit control and tighten to seal.
Do not over tighten into the threaded opening in the PVC pipe.
Over tightening can damage the parts and/or strip the threads cut
into the plastic pipe. Wire the 115°F limit into the pool heater
control circuit as shown in FIG. 2 on page 3. If additional wire
length is needed, use 18 gauge wire for distances up to 30 feet. For
longer distances, size the wire per Table B.
TABLE B
Remote Wire Connection
WIRE GAUGE MAXIMUM ALLOWABLE
LENGTH
12 GA 100 ft.
14 GA 75 ft.
16 GA 50 ft.
18 GA 30 ft.
The system can be installed in either a Full Flow or Diverted
Flow orientation:
Full Flow (reference FIG. 8)
If the total system flow of the swimming pool or spa system
is within five gallons per minute of the recommended system
water flow as shown in Table A on page 1, this type of system is
recommended.
Diverted Flow (reference FIG.’s 9 & 10)
Criteria for installing a diverted flow system is as follows:
• If the total system flow is greater than the amount
required by the indirect heat exchanger.
• Installations with temperatures in excess of 95°F. This is
necessary so the pool high limit will not trip. No water
should enter the pool / spa in excess of 115°F. If the heat
exchanger pool outlet is in excess of 115°F the water must
be tempered down.
• Multiple unit installation.
Example: Total system flow is 500 gallons per minute (GPM). If
two AQUAS Pool Packages (850,000 Btu/hr) were installed, each
of the pool packages would require 90 GPM for a total of 180
GPM of the pool water being diverted through the indirect heat
exchangers while the other 320 GPM would be diverted back to
the pool.
100326095_2000582397_Rev A 2 of 16
Safety High Limit Requirements
Ensure that the 115°F safety high limit control is installed in the
filter system piping. Install the high limit a minimum of three
feet downstream from the point where the heated water from the
indirect heat exchanger is added to the filtration system (see FIG.’s
8 - 10). If the water leaving the heat exchanger is in excess of 115°F
a bypass must be installed to temper the water below 115°F before
re-entering the pool/spa.
The high limit will be mounted in a 3/8" NPT tapped fitting
installed in the filtration system piping or it may be installed
directly into a tapped opening in the PVC filter system piping.
Turn off the filter system pump when installing the high limit in
the filtration system piping. Tapped openings can be added to
the PVC pipe by first drilling 9/16" pilot holes in the PVC pipe at
least three feet downstream of the point where the heated water
from the indirect heat exchanger is added to the filter piping. The
drilled pilot holes can now be carefully threaded with a 3/8" NPT
tap. After the pipe threads have been cut into the PVC pipe wall
the high limit can be inserted into the tapped openings.

Figure 2 Low Voltage Connections
100326095_2000582397_Rev A 3 of 16
LOUVER RELAY
FLOW SWITCH
TANK THERMOSTAT
BUILDING
MANAGEMENT
SYSTEM
COM
NO
SHIELD SHIELD
TO NEXT BOILER
A B
A B
FROM
PREVIOUS
BOILER
AB
NOTE: CONNECTION BOARD SPLIT FOR ILLUSTRATION PURPOSES
WIRE AS
NEEDED
SYSTEM PUMP
SPEED
CONTROL
TANK SENSOR
110°HIGH LIMIT SENSOR
JUMPER R1 TO W1
FROM FACTORY
POOL HEX SENSOR
SMART SYSTEM MULTI-TEMP LOOP CONTROL
OR
DIR #2000546322 00

Line Voltage Connections
The AQUAS pool package has a single point line voltage
connection for the boiler and the pump (FIG. 3). Connect 120
VAC wiring to the line voltage terminal strip in the junction box.
Provide and install a fused disconnect or service switch (15 amp
recommended) as required by local codes. Refer to Table C for
total amps by model.
TABLE C
Model 400 500 600 725 850
Total
Amps <12 <12 <12 <12 <12
DOMESTIC
HOT WATER
PUMP / SECONDARY
HEX PUMP
BOILER
PUMP
120V SUPPLY
LINE
GROUND
NEUTRAL
W
G
BK
SERVICE
SWITCH
L2/N GL1
BK
G
W
BK
G
W
Figure 3 Line Voltage Field Wiring Connections
100326095_2000582397_Rev A 4 of 16

Indirect Heat Exchanger
Installation Instructions
Heat exchangers should be installed downstream of the pumping and filtration equipment (reference FIG. 4).
Pool Water Chemistry
It is essential that the instructions in this section along with
the Ryznar Stability Index and/or Calcium Stability Index are
followed to prevent corrosion / erosion of the indirect heat
exchanger:
- Always keep pH to within correct levels. The ideal pool pH
should be kept to within 7.4 to 7.6.
- Under no circumstances should the pH fall below 7.2 or
rise above 7.8 (see FIG. 5). Check on a day-to-day basis. Alter
pool condition as necessary.
- Ensure that chlorine levels are within the range recommended
by the chemical manufacturer and are in accordance with the
type of pool, for example; private, hotel, school or municipal.
- If a bypass is fitted to the indirect heat exchanger circuit,
it is essential that any or all of the valves are correctly
positioned to allow the recommended pool water flow to pass
through the heat exchanger.
- The system filter unit should be checked regularly, especially
sand filters (to detect sand and diatomaceous earth). Sand
filters, if working incorrectly, can allow sand to pass around
the pool circuit causing erosion of the pipework and heat
exchanger. Keep the pool free from debris such as leaves,
grass cuttings, etc. This foreign matter can cause decay and
increase pH.
- It is essential that the correct amount of chlorine dosage is
added to the pool. To allow proper dispersion of the dose in
the pool water, distribute the chemicals to various areas of
the pool. Do not dose in one area only, as this will create
high acidic areas which can cause corrosion / erosion of the
pool equipment.
Filling the System
The boiler is filled through the pressure reducing auto-fill
valve. The operating pressure of this system is 15 psi between
the heater and the indirect heat exchanger. There are no
adjustments necessary to the fill valve cartridge (factory set).
The expansion tank is set at 20 psi. It is necessary to check
the pressure of the expansion tank when annual maintenance
is performed. The boiler system operates off a city or potable
water system which feeds a closed loop system. A hard line is
piped from the potable water supply to the pressure reducing
valve. This water is to remain on at all times when the system is
in operation.
Pressure Reducing Valve
The valve is equipped with a fast-fill feature that can be used to
override normal operation when filling and purging the system.
To activate fast-fill, push and hold down the fast-fill knob on top
of the cartridge as shown in FIG. 6.
Relieve air from the system through operation of the pressure
relief valve by pulling the lever on top of the valve, causing it
to open.
Figure 6 Pressure Reducing Auto-Fill Valve
Figure 5 pH Scale
Figure 4 Pumping and Filtration Equipment
- Chlorinators must feed downstream of the pool heater and
have an anti-siphoning device to prevent chemical backup
in the heater when the pump is shut off.
High chemical concentrations from
improperly adjusted feeders, chlorinators or
salt levels above 5000 ppm can cause rapid
corrosion to the heat exchanger.
CAUTION
PUSH CAP DOWN TO
ACTIVATE FAST FILL
100326095_2000582397_Rev A 5 of 16
FILTRATION
SYSTEM PUMP
FROM POOL
TO POOL
(DOWNSTREAM)
CHLORINATOR
HI-LIMIT
TEMPERATURE
SENSOR
DIR #2000546268 01

FROM POOL
CPVC
TO POOL
115ºF LIMIT
TEMPERATURE
SENSOR
DIR #2000546271 01
DIR #2000546271 01
DIR
#2000546271
01
Please note that these illustrations are meant to show system piping concept only, the installer is responsible for all
equipment and detailing required by local codes.
NOTICE
Figure 8 Full Flow
Makeup Water Assembly Figure 7 Connecting the Makeup Water Assembly
AUXILLARY
HEAT EXCHANGER
EXPANSION TANK
NIPPLE
PRESSURE
REDUCING VALVE
REDUCER TEE
DIR #2000546270 01
In the following steps, a backup wrench is
necessary to properly attach the makeup water
assembly.
NOTICE
1. Attach the brass reducer tee to the expansion tank as shown
in FIG. 7.
2. Attach the assembly to the AQUAS system.
3. Attach the brass nipple to the brass tee as shown in FIG. 7.
4. Attach the makeup water fill valve to the open end of the
brass nipple.
100326095_2000582397_Rev A 6 of 16

FROM POOL
TO POOL
RECOMMENDED
ISOLATION VALVE
VALVE
THROTTLING
115ºF LIMIT
FLOW METER (2X)
(OPTIONAL)
CPVC
PIPING
TEMPERATURE
SENSOR
LEADER
MEMBER
DIR #2000546281 01
RELIEF VALVE
TEMPERATURE AND
PRESSURE GAUGE
FLOW SWITCH
RECOMMENDED
ISOLATION VALVE
CVPC
FLOW METER
VALVE
THROTTLING
115ºF LIMIT
FROM POOL
TO POOL
TEMPERATURE
SENSOR
DIR #2000546276 01
Adjust valves to provide suggested flow per Table A on page 1.
NOTICE
Figure 9 Bypass (if flow is greater than required by heat exchanger)
NOTICE System flow should always remain higher than the required flow for the boiler(s) when the boiler(s) is in operation
to prevent short cycling and high limit issues.
Please note that these illustrations are meant to show system piping concept only, the installer is responsible for all
equipment and detailing required by local codes.
NOTICE
100326095_2000582397_Rev A
Figure 10 Bypass Multiple Units (if flow is greater than required by heat exchanger)
7 of 16

AQUAS Pool Setup
To access the Installer setting press and hold the Menu/Exit key
until it requires the installer’s code. Proceed and enter #5309
(reference Table D on page 11).
NOTE: NA = No adjustment necessary.
Standalone Operation
Temperature Settings
1. SH1 Set Point (Pool Temperature)
2. Minimum SH Set Point (Pool Temperature Minimum)
3. Maximum SH Set Point (Factory Set 104°F)
4. SH1 Offset (2°F Minimum) number of degrees above the set
point the boiler will turn off.
5. SH1 differential (4°F Minimum) number of degrees below
the turn off temperature the boiler must see before the boiler
will turn on.
Example: Set Point 78°F
Offset = 2 Boiler OFF at 80°F
Differential = 4 Boiler ON at 76°F
Cascade Multiple Units Together
Temperature Settings
1. SH1 Set Point (Pool Temperature)
2. Minimum SH Set Point (Pool Temperature Minimum)
3. Maximum SH Set Point (Factory Set 104°F)
Control Modes
Cascade
1. Controlling Sensor (Not Applicable)
2. BMS Tstat Input (Active / InActive) (Not Applicable)
3. (Not Applicable)
4. BMS (Active / InActive) (Not Applicable)
5. ModBus (Active / InActive) (Not Applicable)
6. Cascade Address (Leader 0) (Member 1, 2, 3, etc.,)
7. Cascade Type (L/L/EFF) See the FTXL I & O Manual for
description and settings.
8. Max Cascade Outlet Set Point
9. Cascade Offset (2°F minimum, this is the warmest the pool
will ever be above temperature)
10. Cascade Off / On Differential (This parameter determines how
much the temperature must be below the turn off
temperature (set point + offset) before the Lead boiler turns
on. Four degrees is the tightest this setting can be.
11. Min On / Off Time (Not Applicable)
12. Min Next On Time (Not Applicable)
13. Boiler Size (Not Applicable)
Example: Set Point 78°F
Offset = 2 Boiler OFF at 80°F
Differential = 4 Boiler ON at 78°F
100326095_2000582397_Rev A 8 of 16

Cascade
When multiple boilers are installed, they can be wired together
in a cascade sequence. A maximum of eight boilers can be
controlled from a single control. In this application one boiler
would be designated as the Leader control and all others would
be designated as Member controls.
If the water temperature at the inlet side of the indirect heat
exchanger sensor is less than the set point + the turn-off offset -
the off-on differential, then the control will initiate a call for heat
on the Cascade (see the FTXL Service Manual for an explanation
of the offset and differential). The Leader will energize the lead
boiler on the Cascade. For a new startup this will be the Leader
boiler.
The boiler will fire at its ignition speed and will then modulate
its firing rate to maintain the set point. If the first boiler reaches
100% of its firing rate, the Leader will calculate at what point the
second boiler could fire at 20% of its firing rate. At this point,
the Leader will fire the second boiler on the Cascade. For a new
startup, this would be the first Member boiler. The boiler will
fire at its ignition speed and will then modulate its firing rate to
maintain the set point.
If the set point still cannot be met, the Leader will continue
firing more Members until either the heat demand is met or all
boilers on the Cascade are firing. As the heat demand decreases,
the last boiler on will modulate down to 20% of its firing rate.
Once the demand for that boiler is zero, it will shut down. As
the heat demand decreases further, the second to last boiler will
modulate down and shut off. This will continue until the demand
is satisfied and all boilers are shut off.
Wiring of the Cascade
When wiring the boilers for Cascade operation, select one boiler
as the Leader boiler. The remaining boilers will be designated
as Members. See “Configuration of the Cascade” for a detailed
explanation of this procedure.
Communication between the Leader boiler and the Member
boilers is accomplished by using shielded, 2-wire twisted pair
communication cable. Connect one of the twisted pair wires
to terminal A on each of the Low Voltage Connection boards
(FIG. 3), and the other wire of the twisted pair to terminal B on
each of the Low Voltage Connection Boards. Connect the shield
wires to one of the shield ground terminals on the Low Voltage
Connection Boards. If more than two boilers are on the Cascade,
daisy chain the wiring from the Sequencing terminals on the
second boiler to the Sequencing terminals on the third boiler, then
from the third to the forth, and so on. The connections between
boilers can be made in any order, regardless of the addresses of
the boilers. Try to keep each cable as short as possible.
Configuration of the Cascade
Please note that the brackets ([]) denote screen
status.
NOTICE
When installed in a Cascade system, the individual controls must
be programmed for cascade operation. This is accomplished by
accessing the control parameters.
Press the [MENU] key for at least five (5) seconds. Input the
Installer code as described in the FTXL Service Manual. Once the
control parameters have been accessed, use the NAVIGATION
DIAL to select the Control Mode parameters. Press the
NAVIGATION DIAL to access these parameters.
Rotate the NAVIGATION dial to select the parameter “Cascade
Address”. Press the NAVIGATION dial to access this parameter.
Each appliance in the Cascade system must be programmed
with its own address. The boiler designated as the Leader will
have an address of 0. The remaining boilers in the Cascade
will be Members and have addresses from 1 - 7. Rotate the
NAVIGATION dial to select the appropriate address. Press the
RIGHT SELECT SAVE key. If installing the boilers in an
existing system, the new boilers should be programmed as the
Leader and/or the higher number addresses.
Press the RIGHT SELECT HOME key to upload the address
into the control. Repeat this procedure for all boilers in the
Cascade, designating the Leader control and the Member controls.
100326095_2000582397_Rev A 9 of 16

AQUAS control module
DIR #2000547501 00
NAVIGATION DIAL
(PRESS OR TURN)
RESET KE
Y
RIGHT SELECT KEY
(SOFT KEY)
LEFT SELECT KEY
(SOFT KEY)
Use the control panel (FIG. 11) to set temperatures, operating conditions, and monitor boiler operation.
The information on the bottom of the display shows the functions of the two SELECT keys (on either corner), and the NAVIGATION
dial (in the center):
MENU = Left SELECT Key
SET POINTS = NAVIGATION Dial - Pressing Down
SHDN = Right SELECT Key
Figure 11 Control Panel
100326095_2000582397_Rev A 10 of 16