Xylem Laing Thermotech E1 Series, Instruction Manual

UltraCirc Models

The BU models incorporate a shut off valve, check valve, and bleed valve  into the brass pump housing eliminating the 

need to install these components. These models are supplied with 1/2” (5/8”) union fittings. These fittings should be 

removed from the pump housing before soldering to avoid damaging the internal valves.

8. Close the shut-off valve on the inlet side of the pump and turn the water supply to the house back on.

9. Flush system of debris.

Before reattaching the pump motor, open the shut-off valve on the inlet side of the pump housing and let water flow 

through the housing. Use a bucket to catch the water. Let the water run long enough to clear all sand, solder pellets, 

plumbers tape flakes, etc. from the lines. Close the inlet shut-off valve when finished.

10. Connect the pump motor to the housing.

Make sure the rubber o-ring is in place in the housing and the screw ring is securely hand tightened. Reopen the shut-

off valve or valves and let the water flood the pump housing.

Do’s and Do Not’s

Do

: 

•  Install an air vent mounted in a vertical position (if provided).

•  Use 1/2”(5/8”) recirculation line tubing.

•  Check to be sure there are no crimps or sharp bends in the recirculation line that would restrict the flow.

•  Be sure the check valve is installed in the proper direction of the flow.

•  Be sure all air is purged from the system prior to starting the pump.

•  Use a water conditioner if you have hard water.

•  Be sure the gate valves are open before turning on the pump.

•  Install the pump pumping in upward direction only.

Do Not

•  Use grease or oil to lubricate the pump (it is self-lubricating).

•  Over tighten the screw ring.

•  Install the pump with the motor above the pump housing.

•  Install the pump pumping away from the water heater nor pumping downward.

•  Start the pump before the system is full of water and purged of air.

•  Allow the water heater temperature above 140ºF (60ºC). (only in the US)

•  Install the pump in the supply line to faucet/taps.

•  Use any pipe size other than 1/2”(5/8”) for all models.

•  Position the pump at the top of the water heater.

Correct Installation

Improper Installation - 

Do NOT mount in these orientations

Note: Keep The Hot Water 

Temperature  Below  140ºF 

(60ºC).  Higher  temperatures 

can cause calcium and 

magnesium elements to come 

out of solution and create 

solids  which  could  not  only 

cause damage to the pump but 

also reduce water heater 

efficiency and premature 

failure of the water heater.

fig. 6

Remove the motor unit and 

o-ring from the pump housing into the plumbing 

line.  Do not sweat the housing into the plumbing 

line with the motor or o-ring attached. Arrows on 

the pump housing indicate the direction of water 

flow.

Caution: Only hand tighten the screw ring. 

Do not over tighten! Do not use plumbers 

putty on the screw ring.

11. Purge air from the supply line.

Turn on the faucet/taps or shower farthest from the water heater. Open the line until you get a good, steady stream of 

water without sputter or evidence of air.

12. Purge air from the return line.

Connect the pump to the electrical supply. With the pump running, open the hose bib/connection and let water run 

until the pump is running quietly and there is no sputtering or other evidence of air coming from the hose bib. Close 

the hose bib. Your system is now in operation. Allow a few minutes for instant hot water to recirculate to all of your 

faucet/taps.

8. Install the pump and other components required in accordance with the diagrams provided in fig. 1 or 2 and 

connect the return line to the water heater. 

Unscrew the pump housing from the motor (fig. 6) and run the pump 

for a few seconds to make sure it is operational.