Automatic water pump MITSUBISHI WP-405R2, power 400 watts

Automatic Water Pump MITSUBISHI WP-405R2 Power 400 W
An automatic water pump designed to provide consistent water pressure, meeting the needs of residential homes and small buildings. With a 400 W motor power, it delivers sufficient water volume for simultaneous use across multiple points. The constant pressure system ensures smooth water flow, eliminating fluctuations between high and low water pressure during use. Built from high-quality materials, it is resistant to corrosion and various weather conditions. The nitrogen pressure tank helps reduce noise and extends service life, while the Thermal Protector prevents motor overheating and enhances safety. Ideal for homes requiring steady water pressure and compatible with water heaters, showers, and multiple faucets running at the same time, the MITSUBISHI WP-405R2 is an excellent choice for households seeking a high-quality, durable water pump.

Specifications
- 400 W motor power delivers sufficient water pressure for general household use
- Constant water pressure automatic system maintains steady water pressure no matter how frequently taps are turned on and off
- Durable materials pump body made of specially coated steel to prevent rust and corrosion
- Brass impeller strong and friction-resistant, ensuring efficient water flow
- Thermal Protector motor protection system automatically shuts down when abnormal high heat is detected
- Nitrogen pressure tank (Nitrogen Tank) prevents pressure drops and reduces operating noise
- IPX4 waterproof rating resistant to water splashing from all directions, extending service life

Suitable Application
- Medium to large residential houses
- Commercial buildings or small offices
- Water systems for water heaters
- Boosting water pressure in indoor piping systems

Mitsubishi round tank or pressure tank water pump
Another water pump brand that has been popular in Thailand for a long time. Features a large pressure tank structure in yellow with a black base, enclosed with an Aluminum Frame Cooling Fan material that helps prevent animals or insects from getting inside and causing noise. The pump head assembly made of copper alloy is durable and rust-free.  The specially designed tank is welded with Seam Welding technology, withstanding high pressure without leaking, and is coated with special non-toxic paint both inside and outside to provide excellent rust prevention. The tank cover is made of special flame-retardant, strong, and durable plastic.  Proprietary air charger rapidly replenishes air to reduce frequent cycling issues. In addition, it features a backflow prevention system and a tank pressure control system, operating automatically based on the opening and closing of water taps. Equipped with a special ceramic seal gasket that is extra thick and durable. Enhanced safety with a ground wire ensures safety during installation and operation. Certified to ISO standards.

 Which type of round tank water pump is suitable for how many stories of a house?
Suitable for general houses with few taps in use that require high delivery pressure 
How many watts of water pump should be used?
1-story house: wattage from 100-200 W should be used
2-story house: wattage from 250-300 W should be used
For a 3-4 story house, dormitory, or commercial building, a wattage of 300 watts or higher should be used.
However, some houses still experience insufficient water pressure despite purchasing according to the recommended wattage for each story. This might be because the house has many rooms or family members requiring higher-than-normal water usage. Therefore, in addition to calculating the wattage based on the number of stories, the actual water consumption in the household must also be taken into account.

Maintenance tips for long-lasting water pump use
1. Observe the operation of the water pump, such as whether the water pressure is normal, the sound is normal, and the pump switches on and off properly.
2. Open the cover periodically to check inside for any leaks.
3. Prevent any water leaks inside the house; leaving leaks unattended for a long time will cause the pump to work harder and more frequently, overloading the motor unnecessarily and increasing electricity costs.
4. Always close the faucet completely immediately after using water.
5. Check the cleanliness of the water in the storage tank to prevent rocks, dirt, and sand from entering the pump.

Basic troubleshooting for common issues with Mitsubishi round tank water pumps
1. Mitsubishi round tank pump cycles on and off frequently
First, suspect that there might be a leak in the water pump or the household plumbing system. Checking is not difficult: simply shut off the discharge valve and observe whether the pump still runs. If the frequent cycling stops → this indicates a leak within the house. However, if it persists, it indicates a leak at the pump itself, which may be caused by worn-out seals or a leaking, degraded pressure tank. 

2. Mitsubishi round tank pump does not run
First, check what type of failure it is: power is connected and there is a humming sound but the motor doesn't rotate, or it is completely silent.

3. Mitsubishi water pump does not work, power is on with a humming sound, but the motor does not rotate 
3.1. It may be due to a deteriorated, shorted, or burned-out capacitor. To check, turn off the circuit breaker, remove the pump cover using a Phillips screwdriver to loosen the screws, and then remove the capacitor cover. Next, inspect the capacitor—the black rectangular component—for signs of swelling or burning. If it is damaged, take it as a sample or check its microfarad (μF) rating, purchase a replacement from a water pump spare parts store, and replace it by reconnecting the wiring. 
3.2. It could be caused by damaged bearings or a jammed impeller. To check, turn off the circuit breaker and use a flat-head screwdriver to turn the rear motor shaft to see if it rotates smoothly. Alternatively, remove the motor cooling fan cover and manually turn the fan to check for smooth rotation. If it does not rotate freely, it may be due to rusty, worn-out bearings or foreign objects trapped inside the impeller.

4. Mitsubishi water pump does not work, does not turn on, and is completely silent; this may be due to no power coming in.
This can be caused by a broken power cord or a faulty pressure switch. To check, verify whether power is reaching the water pump by removing the machine cover, followed by opening the motor capacitor cover. Then use a test light screwdriver to check. If power is normal, it could be a faulty pressure switch. To check: turn off the breaker, open the pressure switch cover with a Phillips screwdriver, and check if the switch is stuck. Fix it by replacing with a new pressure switch.

5. Mitsubishi water pump does not work due to excessive temperature
Current models have an automatic cut-off system to prevent motor burnout. The solution: stop using the water pump, turn off the breaker, wait for the motor to cool down, and then turn it back on.

Mitsubishi round tank water pump makes abnormal noise. Mostly, loud noise occurs from several causes, but mostly there are 
1. The cooling fan impeller is degraded, cracked, broken, or insects have gotten inside causing abnormal noise. Solution: Use tools including a Phillips screwdriver and snap ring pliers. Use the Phillips screwdriver to unscrew and open the fan cover, then use the snap ring pliers to remove the retaining snap ring, pull out the old impeller, insert the new impeller, and reassemble as before.

2. There are stone fragments, sediment, or gravel that slipped into the water pump impeller. Solution: Use a socket or No. 8 T-handle wrench to unscrew and remove the pump casing/impeller cover, taking care not to tear or damage the front pump gasket, then clean and remove all foreign objects completely and reassemble as before.

3. Damaged or worn bearings. Symptoms: continuous loud noise throughout operation.  This may be caused by rust resulting from a worn shaft seal that allowed water into the bearing, or bearings cracked from prolonged service life. The solution must be handled by a skilled technician; it is recommended to contact a nearby technician to inspect it.