LG AHBW Series Installation Manual page 51

Installing recirculation pump
When is used with sanitary water tank, it is STRONGLY recommended to install recirculation pump to prevent
flooding out cold water at the end of hot water supply and to stabilize the water temperature inside the sanitary
water tank.
- The recirculation pump should be operated when sanitary water demand is not required. Therefore, external
time scheduler to determine when the recirculation pump should turn on and turn off is required.
- The operating duration time of the recirculation pump is calculated as follow :
Duration time [minute] = k * V * R
k : 1.2 ~ 1.5 is recommended. (If distance between pump and tank is far, then choose high number.)
V : Volume of sanitary water tank [liter]
R : Water flow rate of pump [liter per minute], which is determined by pump performance curve.
- The pump operating start time should be prior to the sanitary water demand.
Water Out
Water In
Hot water supply
City water
Sanitary
Water Tank
Accessories Installation
Shower
(End of Hot
water supply)
Recirculation
Pump
Check Valve
Installation Manual 51
External
Time Scheduler