Table Of Contents; General Information; Table Of Contents; Theory Of Operation - A.O. Smith RXLD-52 Manual

GENERAL INFORMATION

This manual contains instructions for the installation, operation
and maintenance of the Promax
carefully before installing or using and keep it for future reference.
Intended Applications
The XL Series of heat exchangers provide the means to obtain
an isolated source of hot water for radiant floor or wall heating,
hydronic air handling units and other closed loop applications.
The product line includes single wall and atmospherically vented
double wall heat exchangers with two separate btuh inputs for
each. The XL Series is intended for connection with the
®
A.O. Smith Promax SL line of gas-fired water heaters. This unit
is not to be connected to pool or spa systems having highly
chlorinated water.
Rating Plate
A rating plate identifying the heat exchanger will be found on
the front of the unit. When referring to the heat exchanger, always
have the information listed on the rating plate readily available.
Customer Responsibilities
Please take the time to read not only this manual but also the
warranty sheet enclosed. Warranty of the Promax XL heat
exchanger and its parts will depend on proper installation,
maintenance and operation. Furthermore, the warranty shall be
void if the design or structure of the heat exchanger is, or is

TABLE OF CONTENTS

GENERAL INFORMATION .................................................. 2
TABLE OF CONTENTS ....................................................... 2
THEORY OF OPERATION .................................................. 2
SELECTING EQUIPMENT .................................................. 3
HEAT EXCHANGER PERFORMANCE ............................... 4

THEORY OF OPERATION

The pump on the XL unit draws water off of the top side loop
connection fitting (Supply Fitting), circulates it through the primary
side of the heat exchanger and back to the tank through the
return connection. While passing through the heat exchanger,
the water will lose from 10 to 40 degrees dependent on
application. A field supplied pump on the secondary side will
circulate water into the bottom fitting of the heat exchanger, out
the top and through a heating distribution system such as a
radiant slab or air handler. The rise in temperature for secondary
side fluid is very much dependant on application but should be
designed to provide 10 to 30° rise.
®
XL Heat Exchanger. Read it
attempted to be, modified or altered in any way, including, but
not limited to, by attaching non-Company approved appliances
or equipment. The manufacturer of this heat exchanger will not
be liable for any damages because of failure to comply with the
installation and operating instructions outlined on the following
pages. Use them as a guide to check the propriety of the heat
exchanger installation. You will need to maintain the heat
exchanger and water heater as outlined in their respective
manuals. Equipment in this carton was inspected and verified
to be in good condition at the time it left the factory. When
received, a visual inspection of the equipment should be made
and any damage noted on the delivery receipt. A damage claim
should be filed immediately with the carrier.
ALL TECHNICAL AND WARRANTY QUESTIONS SHOULD BE
DIRECTED TO THE LOCAL DEALER FROM WHOM THE HEAT
EXCHANGER WAS PURCHASED. IF YOU ARE UN-
SUCCESSFUL, PLEASE WRITE TO:
Repair Parts
For service or repair parts contact:
First: The Installing Contractor
Second: The local Distributor
AOSmith Water Products Company, Inc.
500 Lindahl Parkway
Ashland City, TN 37015
www.aosmithwaterheaters.com
TYPICAL INSTALLATION ................................................. 5,6
WIRING ................................................................................ 6
MOUNTING THE HEAT EXCHANGER
TO WATER HEATER ........................................................ 6,7
REPLACEMENT PARTS ...................................................... 8
2
FIGURE 1