Xylem IM 16 Seal-less Centrifugal Canned Motor Pumps For Instant Hot Water Recirculating System (obsolete) - Manual

Installation & Operating Manual
Please read this manual carefully before attempting to install, operate or maintain the product described. Failure to
comply with the information provided in this manual could result in personal injury and/or property damage. Retain
this manual for future reference.
Laing Thermotech
Instruction Manual
INSTALLER: PLEASE LEAVE THIS MANUAL FOR THE OWNER’S USE.
Seal-less Centrifugal Canned Motor Pumps
For Instant Hot Water Recirculating System
SM-303/353-B SMT-303/353-B SM-909/959-B14 SMT-909/959-B14
UC-303/353-B UCT-303/353-B UC-909-BW-14 UCT-909-BW-14
with 24 hour timer with 24 hour timer
with 24 hour timer with 24 hour timer
About Recirculation Systems
Air in the System: A properly installed system should include a method of automatically venting the
air that enters the water supply line during use. Air enters the system each time fresh, cold water is
introduced into the hot water heater. Air may also enter the system any time a plumbing line is
opened, for instance during a faucet/taps change or adding a sprinkler system.
Water Pressure: A recirculating system is a pressurized system operating at the city water pressure, as
determined by the pressure regulator on your line, or by a well pump, if you are on a well system. In
most residential plumbing systems, water pressure is set at 35 psi (241 kpa) and above. Below 35 psi (241
kpa), water pressure may not be sufficient to fill the pipe diameter, leaving space for air to accumulate
in the lines. If your system pressure is less than 35 psi (241 kpa), use the next larger pump on the Pump
Selection Guide.
Multiple Floors: Because the system is pressurized, the number of floors in a home is not taken into
consideration in sizing the circulating pump. The pump has only to produce continuous flow at a
pressure sufficient to overcome the friction losses created by the piping in the house water supply line
and the return line.
SM(T)-303/353-B
SM(T)-909/959-B14(18,21,26)
SM(T)-1212/1212B-18(21,26)
UC(T)-303/353-B
UC(T)-909/959-B-14(18,21,26)