Automatic water pump HITACHI WM-PV250XX2 (250 watts)

Automatic Water Pump HITACHI WM-PV250XX2 (250 Watts)

     For pumping water from shallow wells (depth not exceeding 8 meters) or from above-ground water tanks. Easy to use with an automatic system operating in sync with the turning on and off of faucets. Compact size, space-saving installation. Delivers constant, stable pressure, eliminating the issue of interrupted water flow while using a water heater. Suitable for residences using water at multiple points simultaneously.

What are the key advantages of a square tank pump or constant pressure pump?

   Constant Pressure Water Pump Hitachi Eliminate inconsistent water pressure issues with a compact yet high-efficiency water pump. Designed for pumping water from shallow wells (up to 8 meters deep) or above-ground water tanks. Easy to use with an automatic system that activates according to the turning on and off of faucets. Compact size saves installation space. Provides consistent and stable pressure, preventing water interruptions while using a water heater.

- High power in a compact size, saving installation space
- Bladder Tank: The tank contains a rubber diaphragm filled with nitrogen gas requiring no gas refills throughout its lifespan, providing consistent and stable water pressure
- Durable and rust-free: Free from rust throughout its lifespan, rust-proof body, durable and strong
- Pressure Stabilized Unit: Regulates water flow rate and generates continuous pressure
- Brass Impeller: Newly designed pump in a Pyramid Shape delivers more water volume than before
- Safe: Equipped with a “Water Temp Relay” temperature sensor at the pump head and a “Thermal Relay” in the coil that cuts off operation when overheating, preventing other spare parts from heat damage
- Special Material: Pump cover made of special “PPV0” flame-retardant material to prevent the spread of fire
- Ventilation Fan Set: Helps dissipate heat from the unit, extending motor lifespan
- Easy to install for operation 
- Energy Label No. 5: Energy-saving label, highly cost-effective.
- Made of high-quality aluminum, heat-resistant, flame-retardant
- The water pump should only be used with clean water for domestic consumption

Key features of Hitachi water pumps 

- Constant pressure with a specially designed Life-Extending Pressure-stabilized Unit that regulates water flow rate.
- Equipped with a nitrogen pressure tank that ensures steady water pressure without needing gas refills throughout its lifespan.
- All Hitachi water pump models are certified with the Level 5 Energy Efficiency Label and offer maximum efficiency according to industrial standards. 
- Strong, durable motor that prevents rust corrosion, backed by a 5-year motor warranty.
- Brass check valve closes tightly, eliminating air entry into the system; rust-resistant

How to maintain a Hitachi water pump 

1. Observe pump operation, such as whether water pressure flows strong and normally, whether the sound is normal, and whether the pump cuts in and out properly.
2. You should open the cover to check the interior for any leaks.
3. Prevent any leaks inside the house. If leaks are left unattended for a long time, the water pump will work harder and more frequently, overloading the motor unnecessarily and increasing electricity costs.
4. Always close the faucet completely right after use.
5. Check the cleanliness of the water in the water tank to prevent debris, dirt, and sand from entering the pump.
6. Build a sun and rain shelter to extend its service life.

Basic troubleshooting guide for abnormalities in HITACHI square tank pumps

HITACHI square tank water pump making abnormal noise 
Find the source of the noise. In most cases, loud noises come from 3 main points: the water impeller, the cooling fan, or the shaft bearings. 
Water impeller: Mostly caused by foreign objects getting trapped inside the impeller, such as gravel or stones. To fix, use an 8 mm socket or T-wrench to remove all 4 bolts, then remove the cover, clean the impeller thoroughly, and reassemble.
Cooling fan: Common issues include the motor cooling fan becoming loose, degraded, broken, or having small animals or insects inside. Fix by removing and replacing with a new fan blade. 
    1. Use a Phillips screwdriver to loosen the screws securing the cover. 
    2. Use retaining ring pliers to expand and remove the impeller snap ring, then gently pull out the damaged fan blade. 
    3. Then install the new fan blade back into the original position. 
    4. Reassemble the parts.
Shaft bearings: This issue is usually caused by damaged bearings due to degraded waterproof seals, allowing water to enter the bearings and cause rust. The solution is to replace both the seal and bearings. Since this repair is difficult and involves multiple complex steps, contacting a nearby service center is recommended. 

HITACHI water pump running frequently or cycling too often
This problem is usually caused by leaks, either in the water pump itself or within the household plumbing. Here is a simple test method: close the outlet water valve and observe whether the water pump returns to normal. If it stops cycling, it means there is likely a water leak in the home's plumbing system or at water fixtures (such as faucets not closed tightly, leaking, or cracked). However, if the outlet valve is closed and the pump still continues to cycle abnormally, it indicates the issue may be with the pump itself—such as worn or damaged spare parts like a leaking front pump seal, leaking shaft seal, or cracked casing. Fix it by replacing with new spare parts.

HITACHI square tank water pump not working
     1. HITACHI water pump not working due to the thermal cut-off system: The motor overheats beyond the limit, which may be caused by heavy load from a dry water tank, leaks, or continuous running until overheating occurs. The system automatically cuts off power to prevent the motor from burning out. The fix is simply to unplug the pump, wait for the motor to cool down, and then plug it back in for use. 
     2. HITACHI water pump not working due to a stuck or deteriorated pressure switch: If the pump has been used for several years, the pressure switch can stick due to rust. To fix this, turn off the circuit breaker, use a Phillips screwdriver to unscrew the pressure switch cover, and check for any burn marks or short circuits. If none are found, use a brush or spray anti-rust fluid, scrub it with a brush, and press the copper contact points together gently several times until smooth. Wait for it to dry, then turn on the circuit breaker to check if it works. (However, if the pressure switch is still brand new, you can rule out this method as the issue may stem from other causes.)
     3. The Hitachi water pump not working due to no power supply to the pump: To check, use a Phillips screwdriver to loosen the screws and remove the machine cover and condenser cover. Then use a voltage tester screwdriver to touch the wiring terminals connected to the motor, testing multiple points alternately to see if power is supplied. If there is no power coming in, check the wall outlet or circuit breaker again.  
     4. The Hitachi water pump not working due to a degraded, defective, or shorted capacitor:  To check, use a Phillips screwdriver to loosen the screws and remove the machine cover and condenser cover. Then check the capacitor  (the black rectangular component) to see if it is swollen, burned, or abnormal. If abnormal, fix it by replacing it with a new one. 
     5. The Hitachi water pump is not working due to a shorted or burned motor. This problem rarely occurs in modern water pumps today because they have extensive motor protection systems. Motor damage or shorts usually result from heavy overloading of the pump or prolonged use over time. Solution / Inspection: It is recommended to have a technician inspect it thoroughly to be certain, and then resolve it by replacing with a new motor or rewinding the motor, which can be almost as costly as buying a new pump. 

How to install a Hitachi square tank water pump

Water pump installation equipment
- PVC pipe cutter scissors, saw
- Pipe wrench
- PVC pipe glue or solvent cement
- Ball valve
- Check valve 
- Tee fitting
- Elbow fitting
- Male straight connector 
- Straight connector size 
- PVC pipe 
- Teflon thread seal tape 

The water pump should be installed with a dual system: using water boosted by the pump, and bypassing the pump directly in case of a power outage or tap water interruption.

- Prepare the area for placing the water tank and the pump; there should be a roof to protect from sun and rain for a longer service life.
- Place the water pump as close to the water tank as possible for maximum efficiency.
- Connect the pipe from the water meter by first shutting off the meter valve, then connect a tee fitting to split the flow into the water tank and directly into the house.
- Run the pipe into the water tank, installing 1 ball valve to shut off the water for maintenance, and properly install the float valve inside the water tank.
- Screw straight threaded adapters into the tank's water outlet and the pump, wrapping Teflon tape clockwise around the threads about 10–15 turns. 
- Connect the pipe to the ball valve properly, then install the pipe line from the water tank to the water pump, with the ball valve positioned between the water tank and the water pump.
- Then connect the water outlet pipe with another ball valve, followed by a tee fitting connecting to the house and the municipal water supply
- Run a pipe from the meter and tank tee to connect to the tee in front of the water pump, with 1 check valve installed in between to prevent backflow when water is drawn from the water pump. 
- Connect the electrical wiring to the water pump while keeping the circuit breaker turned off.
- Open the water valves at the meter and at the tank inlet; wait until the water tank is completely full.
- Open the valve from the water tank to the pump while keeping the outlet valve closed.
- Turn on the water pump's circuit breaker, then wait a moment for the pump to run and then stop. 
- Open the outlet valve leading into the house, then test the pump's operation by opening and closing faucets inside the house. That completes the installation.

- Prepare the area for placing the water tank and the pump; there should be a roof to protect from sun and rain for a longer service life.

- Place the water pump as close to the water tank as possible for maximum efficiency.

- Connect the pipe from the water meter by turning off the meter's water valve first, then connecting with a tee fitting to divert water to the tank and directly into the house.

- Run the pipe into the water tank, installing 1 ball valve to shut off the water during maintenance, and properly connect the float valve inside the water tank.

- Connect the straight union connector to the water tank outlet and the pump unit, wrapping Teflon tape clockwise around the threads for about 10-15 turns.

- Connect the pipe to the ball valve properly, then install the pipe from the water tank to the water pump, placing the ball valve in between the water tank and the pump.

- Then connect the outlet pipe with another 1 ball valve, followed by a tee fitting connecting to the house and the main water supply.

- Open the water outlet valve leading into the house, then check by turning faucets on and off inside the house to test the pump's operation. This completes the installation.