GRE HPG25, Owner'S Manual, Page: 17 / 278

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3.8 Initial operation
Note: In order to heat the water in the pool (or hot tub), the filter pump must be running to cause the
water to circulate through the heat pump. The heat pump will not start up if the water is not
circulating.
After all connections have been made and checked, carry out the following procedure:
1. Switch on the filter pump. Check for leaks and verify that water is flowing from and to the swimming pool.
2. Connect power to the heat pump and press the On/Off button on the electronic control panel. The
unit will start up after the time delay expires (see below).
3. After a few minutes, check whether the air blowing out of the unit is cooler.
4. When turn off the filter pump , the unit should also turn off automatically , if not, then adjust the flow
switch.
5. Allow the heat pump and the filter pump to run 24 hours a day until the desired water temperature is
reached. The heat pump will stop running at this point. After this, it will restart automatically (as long as
the filter pump is running) whenever the swimming pool water temperature drops 2 degree below the set
temperature.
Depending on the initial temperature of the water in the swimming pool and the air temperature, it may take
several days to heat the water to the desired temperature. A good swimming pool cover can dramatically
reduce the required length of time.
Water Flow Switch:
It is equipped with a flow switch for protecting the HP unit running with adequate water flow rate .It will turn o
n when the pool pump runs and shut it off when the pump shuts off. If the pool water level higher than 1 m
above or below the heat pump’s automatic adjustment knob, your dealer may need to adjust its initial start
up.
Time delay - The heat pump has a built-in 3-minute start-up delay to protect the circuitry and avoid
excessive contact wear. The unit will restart automatically after this time delay expires. Even a brief power
interruption will trigger this time delay and prevent the unit from restarting immediately. Additional power
interruptions during this delay period do not affect the 3-minute duration of the delay.