DuraFlow

Installation and Operation Instructions
Document 2110A
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Installation
and Operation
Instructions for
2400-382A
Water Heater
A subsidiary of BRADFORD WHITE Corporation
LAARS Heating Systems Company
Page 2
TABLE OF CONTENTS
SECTION 1.
General Information
SECTION 2.
Remote Bulb Aquastat Controller
1A.
1B.
1C.
2A.
2B.
2B-1.
2B-2.
2C.
2D.
Introduction ................................................... 3
Piping ........................................................... 3
Wiring ........................................................... 5
Application .................................................... 5
Installation .................................................... 5
Mounting with Boiler Fitting .......................... 5
Wiring ........................................................... 5
Adjustments .................................................. 6
Checkout ...................................................... 6
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DuraFlow Water Heater
Page 3
SECTION 1.
General Information
1A. Introduction
The DuraFlow water heater / buffer was
designed and developed specificaly as a companion
for modern low mass, high efficiency heating boilers.
When piped between the supply and return it
provides a twenty gallon buffer in the hydronic
system. This is typically required in systems with
three or more zones to store and release heating
capacity when only a single zone is operating.
As a water heater, it utilizes the rapid heat-up
ability of low mass boilers to immediately convert this
energy to a steady state continuous domestic output.
In single residential applications when provided
with a properly piped mixing valve and flow restrictor
(see Figure 2) it is the hot water source with a twenty
year warranty.
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*Minimum Clearance
Dimension
1B. Piping
When the DuraFlow is utilized as a domestic
water indirect, it may be piped as a zoned indirect
utilizing conventional circulator or zone valve piping
and wired with domestic water priority. In this and
buffer applications, the DuraFlow must always be
piped with a thermally trapped tempering valve and
flow restrictor set for applicable boiler input.
When utilized as both a buffer and a domestic
water indirect, the DuraFlow is piped to the heating
system supply and return headers or as the bypass on
systems requiring primary / secondary piping. No
zone valve or circulator should be piped in series with
the DuraFlow. In most applications the boiler pump
Figure 1. Dimensions and Connections.
(internal or external) serves as the flow means
between the boiler and tank when used as a buffer.
In multi-unit residential applications with a
single hydronic heating system, it serves as the heat
exchanger source for single or multi tank domestic
water storage.
When piped as a buffer and an indirect domestic
water source to a storage tank, a tempering valve and a
flow restrictor are not required.
ALTERNATIVE APPLICATIONS
RECOMMENDED
ANTI-SCALD VALVE
SUCH AS SPARCO
OR DANFOSS
PRESSURE
RELIEF VALVE
STORAGE
TANK
REQUIRED
FLOW
RESTRICTOR
(SUPPLIED)
DURAFLOW
AQUASTAT
COLD
OPTION 1
Figure 2. Domestic Hot Water Piping.
OPTIONAL RETURN LINE PIPING
OPTION 2
LAARS Heating Systems Company
Page 4
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Figure 3. Piped as Buffer and Indirect.
ZONE THERMOSTATS
DURAFLOW
WATER HEATER
AQUASTAT
TRANSFORMER
NO
RELAY
C
NC
ZONE
VALVES
L2
L1
DISCONNECT
SWITCH
LOW
MASS
BOILER
TERMINALS
Figure 4. Zoning with Valves.
L2
G
L1
T T
NOTE: Pump Operates From
C1-C2 Terminals On Boiler Aquastat.
DuraFlow Water Heater
1C. Wiring
Wire relay (see Figure 4) to reverse acting
aquastat (supplied) to start boiler and system pump.
For maximum domestic water capacity, aquastat must
be wired in priority (as shown) or utilize multiple zone
relay with priority.
Page 5
SECTION 2.
Remote Bulb Aquastat Controller
2A. Application
This remote bulb, immersion-type controller
operates in response to temperature changes in
hydronic heating systems and in other heated liquids.
It provides spdt switching for three wire circuit
applications, combining low limit and circulator
control.
Switch ratings are shown on the inside cover.
The electrical requirements of controlled equipment
must not exceed these ratings.
The R to B contacts make to start the boiler when
the boiler water temperature drops to the dial setting
less the differential. The R to W contact breaks to
prevent circulator operation. When the boiler water
temperature rises to the dial setting, R to B breaks and
R to W makes (see Figure 5).
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2B. Installation
WARNING
CAN CAUSE PROPERTY DAMAGE, SEVERE
INJURY OR DEATH. This product is intended for
use only in systems with a pressure relief valve.
Caution
Disconnect the power supply before beginning
installation to prevent electrical shock or equipment
damage.
Figure 5. Internal View of Remote Bulb Aquastat
Controller.
2B-1. Mounting with Boiler Fitting
1. Screw the fitting into the boiler or pipe
tapping.
2. Place the packing nut on the tubing.
3. Slide the bulb completely through the
fitting to bottom third of tank.
4. Place the composition disk and four slotted
brass washers on the tubing in the order
shown in Figure 6. Turn brass washers so
that the slots are 180 degrees to each other.
5. Slide the seal assembly into the fitting and
tighten the packing nut.
2B-2. Wiring
Be sure all wiring agrees with applicable codes,
ordinances, and regulations for wire size, type of
insulation, and enclosure. The controllers are provided
with conduit knock-outs in the top and bottom of case.
Refer to Figure 7 for typical connection diagram.
Figure 6. Mounting the Boiler Fitting.
LAARS Heating Systems Company
Page 6
2C. Adjustments
Set the differential to correspond with the boiler
manufacturer recommendations. To adjust models
with adjustable differential, rotate the wheel on the
back of the snap switch until the desired reading is
aligned with the V notch in the frame. The wheel
provides an adjustment from 5 to 30 degrees (F).
Replace the cover on the aquastat controller.
Adjust the control point to correspond with the
boiler manufacturer's recommendations. To adjust,
insert a screwdriver in the slotted screw-type head
located beneath the window in the cover. Turn the
scale to the desired control point.
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2D. Checkout
Check to make certain the aquastat controller is
installed and adjusted properly. Operate the system
and observe the action of the device through several
cycles to make certain that it provides proper low limit
cut-out protection and circulator control. Make any
further adjustments needed.
Figure 7. Typical Connection Diagram for an Oil-Fired
Hydronic Heating System That Provides Year Around
Domestic Hot Water.
DuraFlow Water Heater
Page 7
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Laars Warranty
DuraFlow Water Heater
This product is backed by this
limited twenty year warranty to assure your complete satisfaction.
Laars warrants each DuraFlow to be free from defects in material and workmanship according to the following terms, conditions and
time periods:
COVERAGE:
A.
First Year Warranty includes repair replacement, at the option of Laars, of all parts which within one year after original
installation are found to be defectively manufactured.
B.
Second through Twentieth Year Warranty includes: repair or replacement, at the option of Laars, of the storage tank and
heat exchanger, if found and reported during the second through twentieth year after the original date of installation, to have
been defectively manufactured. The water heater owner shall pay the following percentage of the manufacturer's then current
list price at the time of the claim for repair or replacement of those defective parts:
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Year of Claim
Percentage Paid
by Customer
2-5
6&7
8&9
10 & 11
12 & 13
14 & 15
16 & 17
18 & 19
20
0%
50%
55%
60%
65%
70%
75%
80%
90%
C.
In the absence of suitable proof of installation date (Bill of Sale or warranty card registration), the specified warranty period
will commence 30 days after the date of manufacture.
D.
This warranty extends only to water heaters in residential applications which have been properly installed, operated and
maintained. This warranty is nontransferable and applies to the original owners at the original installation location. Laars
makes no express warranties other than the warranties contained herein.
EXCLUSIONS:
A.
First Year Warranty Excludes:
1. All labor charges incurred by any person in connection with the examination, replacement and/or repair of parts
claimed to be defective.
2. Malfunction of parts due to improper application installation or operation.
3. Failures resulting form abuse, accident, negligence, freezing or acts of God.
4. Damage caused by hard water, scale buildup, excessive oxygenation or external leakage.
B.
Second through Twentieth Year excludes: All of above "Part A" plus: Insulation and mechanical components furnished to
Laars by other manufacturers, such as pumps, relays, controls, gauges, etc. Such components may carry warranties from
their respective manufacturers and Laars has requested its dealers to assist consumers in obtaining performance of any
warranties which may service such components.
C.
Laars requires all alleged defective part(s) be returned through trade channels and replacement part(s) will, if warranty
conditions are met, be provided by Laars through the wholesaler. In this case, the cost of shipment to Laars is borne by the
customer.
PROCEDURE FOR WARRANTY SERVICE
For Warranty service, contact your installing contractor with the following information: Water heater model number, serial number
(located on the water heater rating plate) and the date of installation. The installing contractor will notify the wholesaler from whom
the water heater was purchased. All alleged defective part(s) must be returned through trade channels and replacement part(s) will if
warranty conditions are met, be provided by Laars through the wholesaler. If there are any questions about the coverage of this
warranty, please contact Laars at the address shown below.
LEGAL RIGHTS
No other party is authorized to make any other warranties on Laars’ behalf. No other warranty expressed implied, including warranty
of merchantability or fitness for a particular purpose is made, This warranty does not extend to liability for incidentals, special or
consequential damage.
2400-382A
Some states and provinces do not allow limitations on how long as implied warranty lasts or the exclusion or limitation of incidental or
consequential damages, so the above limitation or exclusions may not apply to you. This warranty gives you specific legal rights, and
you may also have other rights which very from state to state and by province.
20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax 603.335.3355
1355 Kuehner Drive, Simi Valley, CA 93063 • 800.900.9276 • Fax 800.559.1583 (Sales, Service)
1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax 905.366.0130
www.Laars.com
Litho in U.S.A. © Laars Heating Systems 0704 Document 2110A