Series E1 and E3 Instant Hot Water Recirculating Systems
Installation, Operation and Service Instructions
INSTALLER:
PLEASE LEAVE THIS MANUAL FOR THE OWNER’S USE.
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 does not need to be taken into consideration in sizing
the circulating pump. The pump only has 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.
Oversized Pumps
Pumps should not be so large as to produce flow rates that may eventually erode holes in the pipes. According to the
Copper Development Association, excessive erosion occurs at a velocity of about 5ft. (1.5m) per second and higher; or
about 4 GPM (15 LPM) in 1/2” (5/8”) Type M copper pipe; and 8 GPM (30 LPM) in 3/4” pipe. Use the recommended
recirculation line size shown in the Pump Selection Guide. Bell & Gossett pumps are sized so that flow velocities are well
below these limits.
NOTE: Bell & Gossett recommends Bronze or Stainless Steel Booster Pumps be used for pumping potable
water.
WARNING:
Before Installing, using or servicing this product, read the instructions. To reduce risk of electrical
shock see instructions for proper installation.
CAUTION:
For supply connections use wire suitable for at least 221
º
F (105
º
C). Use copper conductors only.
WARNING:
California Proposition 65 Warning! This product contains chemicals known to the state of
California to cause cancer and birth defects or other reproductive harm.
WARNING:
Risk of electric shock; this pump has not been investigated for use in swimming pool and marine
areas
. - Non submersible Pump -
Installation & Instructions for Instant Hot Water Recirculating Systems
Laing Thermotech
Instruction Manual A-00-091-376
