Description Of Question; Analysis; Troubleshooting; Instruction For "Leaving Out Charging Water" Between Generator And Water Tank - Gree GMV-S120WL/A-S Service Manual

3. Instruction for "leaving out charging
water" between generator and water tank

3.1 Description of question

When installing GMV Unic unit, after connecting circulating water pipe between hydro box
(NRQD16G/A-S) and water tank, it has not charge water or drive out the air in the circulating water
pipe, but charge water and drive out air in the water tank. Later in debugging, the unit will apprear
―water flow switch fault LL‖, ―high pressure protection E1‖, ―temperature sensor falling dU‖, ―water
pump is damaged‖, and other malfunctions.

3.2 Analysis

As shown in the following picture: the matching water tank of hydro box (NRQD16G/A-S) is
―water tank with inner heat exchange coil pipe‖, model of water tank is ―SXVD***LCJ*/A-K‖.
―Circulating water pipe‖ and ―heat exchange coil pipe‖ are through, after heating the water
inside ―circulating water pipe‖ by generator, the hot water inside circulating water pipe will heat the
water inside water tank via heat exchange coil pipe. So the ―water inside water tank‖ is separated
from ―circulating water pipe‖. ―Circulating water pipe‖ must be independently charged with water to
drive out the air.
If the circulating water pipe has not been charged with water and driven out the air, then there
will be no water inside the generator to conduct heat exchange with refrigerant, and then the
pressure in the system will be high that will cause ―high pressure protection‖; water pump will be
idling, and water flow switch will failure to actuate, which will lead to ―water flow switch
malfunction‖, ―water pump is damaged‖; when the temperature detected by temperature sensor of
generator circulating water pipe inlet and outlet is changeless, it will cause ―temperature sensor
falls out‖ and related malfunction.

3.3 Troubleshooting

When such problem arises, please charge water and drive out the air in ―circulating water pipe‖
between generator and water tank strictly according to requirements of instruction manual. The
following are related steps.
(1) Leak detection: after all the water pipelines are connected, first conduct leak detection,
and then conduct heat insulation for all the water pipeline system, especially for the valves, joints
of pipe. It is recommended to use heat insulating cotton with the thickness not less than 15mm.
(2) Charge water and drive out the air among generator, water tank and floor heating pipe:
A. Make sure that each water pipeline has been connected, close the air outlet valve of hot
water generater, and ensure that the drain outlet has been closed;
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