Automatic water pump, constant pressure, MITSUBISHI EP-405R2, size 400 watts

Constant Pressure Automatic Water Pump MITSUBISHI EP-405R2 size 400 W
Automatic Water Pump MITSUBISHI EP-405R2 size 400 W Designed for homes requiring constant water pressure, supporting simultaneous use at multiple points such as showers, washing machines, or multiple taps. The unit is made of high-quality materials, durable, and equipped with a motor burnout protection system. (Thermal Relay) and Large pressure tank makes water delivery more efficient

Key Features
✔ Automatic system, turns the pump on and off according to water usage
✔ Constant water pressure, delivers consistent water pressure to all points
✔ Large pressure tank coated with anti-rust agent, durable for long-term use
✔ Special resin impeller, corrosion-resistant, rust-free
✔ High-quality motor with good heat dissipation, long service life
✔ Motor burnout protection system (Thermal Relay) prevents damage from electrical overload
✔ Special coated body, protects against rust and corrosion

- High-power motor delivers strong, durable water delivery; redesigned sealed construction with Aluminium Frame Cooling Fan and heat-dissipating fins; enclosed to prevent animals or insects from entering the motor; quieter operation; delivers a higher water flow rate
- Electronic control system (Flow Switch), the latest innovation for precise water flow detection, working synchronously with the pressure control switch for rapid response; made from high-grade materials for long service life; features an external cover and silicone-coated internal circuit board for enhanced protection against water and dust
- Pressure control switch controls operation automatically, switching on and off completely silently, eliminating noise problems
- Wiring box protects the wiring set and capacitor from water, insects, and rodents; further reinforced with a specialized internal steel casing covering the capacitor 
- 5-year motor warranty with Thermal Protector to prevent motor burn-out under abnormal operating conditions and an added Thermostat to shut off operation when water temperature rises or when there is no water entering the unit
- Automatic water boost system activates whenever water is used, delivering continuous water flow and maintaining consistent volume, making it ideal for household water heaters or showers
- Pressure tank filled with nitrogen gas with rubber diaphragm, durable, rust-free, providing consistent pressure throughout its service life
- Compact size saves more installation space, 2-way selectable water outlet (except for EP-505Q5 which has a single outlet) adds installation convenience and a neat look. Specially designed base prevents standing water, made of high-quality materials, sun and rain resistant 
- Pump head assembly made of copper alloy, making it durable and rust-free 
- Backflow prevention system with a disc-type check valve moving vertically, completely sealing water at all times 
- Extra-thick plastic cover made of flame-retardant material, weather-resistant in all conditions, with cover retaining screws for increased strength and safety
- Pump housing utilizes new technology with high-quality plastic, reducing the number of mounting bolts to minimize the chance of rust both internally and externally
- Added ground wire for safety during installation and operation      
- Maximum energy saving No. 5 (except EP505Q5)

Constant pressure automatic water pump or square tank water pump
Featuring an operating principle with a nitrogen pressure tank, it generates pressure immediately whenever water is turned on without waiting for water pressure in the pipe to drop to a certain level, providing consistent water pressure during use and delivering equal water pressure to every tap. Mitsubishi's constant pressure automatic water pump has been extremely popular for years, especially in Thailand. It has a compact square shape in yellow and black, and features continuous innovations such as the newly redesigned U-shaped impeller—patented exclusively by Mitsubishi Electric—which increases water discharge surface area and reduces resistance, delivering higher water volume with a continuous, powerful stream. The aluminum frame motor comes with a 5-year warranty and a thermal protector to prevent motor burnout, ensuring a long service life. It uses non-flammable materials for superior safety and environmental friendliness under RoHS standards. 

- Double Safety protects the wiring harness and capacitor from water, insects, and the wiring box, covered with an additional steel box layer using flame-retardant materials 
- Thermo protector shuts down operation when the temperature is too high
- Sus-joint and Housing adds a locking system connecting the suction pipe to the housing to prevent movement, boosting confidence in quality and preventing leakage issues 
- Electronic Flow Switch circuit board accurately monitors water usage, coated with waterproof resin, covered with a plastic box made of flame-retardant material, along with an additional steel box for enhanced safety; Nitrogen tank provides strong, steady pressure with confidence from Energy Efficiency Label No. 5 up to 3 stars

What type of house is the Mitsubishi square tank water pump suitable for?
Suitable for general houses and commercial buildings with water fixtures requiring constant pressure, such as water heaters and rain showers. Compact, space-saving design. What wattage water pump should you use?
First, you should determine the water usage points and the number of residents in the house—how many points of water use are needed or how many people will be using water. If multiple points are used simultaneously, water pressure might be insufficient. Typically, pump selection guidelines are as follows: 
1-2 storey house, 2-3 residents: use a 100-150 watt water pump
2-storey house, 4-5 residents: should use a water pump of 200 watts or more 
3-4 storey house or commercial building, 6 or more residents: should use a 300 watt or higher water pump. However, keep in mind that higher wattage consumes more electricity, so choose appropriately. Alternatively, you might opt for a pump with an advanced automatic system that controls water delivery electronically; this saves power even at high usage levels, though the price of such pumps is also relatively high.

Basic troubleshooting methods for abnormal symptoms of square tank water pumps
1. Mitsubichi square tank water pump makes abnormal noise. Most noise occurs from various causes, but mostly there are
- The cooling fan is deteriorated, cracked, or broken, or insects got inside causing unusual noises. Solution: Use a Phillips screwdriver and snap ring pliers. Unscrew the fan cover using the Phillips screwdriver, use the snap ring pliers to remove the retaining ring on the fan, pull the old fan out, insert the new fan, and reassemble as before. 
- Stones, sediment, or gravel slipped inside the water impeller. Solution: Use an 8 mm socket wrench or T-handle socket wrench to unscrew and open the impeller cover, taking care not to tear or damage the front pump gasket, then thoroughly clean and remove all foreign objects and reassemble as before. 
- Bearings are damaged or deteriorated. Symptoms include continuous loud noise during operation. This could be caused by rust from a deteriorated shaft seal allowing water into the bearing, or bearing failure due to wear and tear. Solution: Must be performed by a professional technician; it is recommended to contact a nearby technician for an inspection. 

2. Mitsubishi constant-pressure square-tank water pump does not run
A water pump not operating can also stem from several causes, but the most common ones encountered are as follows:
- The Mitsubishi water pump does not run due to excessive temperature: current pump models feature a thermal cut-off system to prevent the motor from burning out. Solution: Stop operating the water pump, switch off the circuit breaker, wait for the motor to cool down, and then turn it back on.
- The Mitsubishi water pump does not run due to a stuck or deteriorated pressure switch. Solution: Switch off the circuit breaker, use a Phillips screwdriver to open the cover and remove the pressure switch, then press it to check if it functions normally, or it may need to be replaced with a new pressure switch. 
- The Mitsubishi water pump does not run due to a lack of power supply, which may be caused by a broken power cord or no power from the source at all. How to check: Use a test pen to check at the circuit breaker, or remove the machine cover and the condenser cover using a Phillips screwdriver, then use a test pen to check for electric current. 
- The Mitsubishi water pump does not run due to a damaged or degraded condenser/capacitor. Solution: Turn off the circuit breaker, remove the machine cover and capacitor cover, and inspect the capacitor for swelling or short-circuiting; resolve the issue by replacing it with a new capacitor. 
- The Mitsubishi water pump does not run due to motor damage or short-circuiting, which is quite rare but can happen if the water pump is overloaded or worn out over a long service life. How to check or fix: This may require technical expertise; it is recommended to call a technician for inspection. 

3. Mitsubishi water pump surges/cycles intermittently
The water pump surges or cycles on and off rapidly, which may be caused by a water leak at the pump or within the household plumbing system. How to check: Close the outlet water valve and observe whether the surging stops. If it stops, this indicates a leak in the home's plumbing system, such as a dripping tap or a faucet that is not completely closed. If the surging does not stop after closing the outlet valve, it may be caused by a leak at the pump itself, such as a cracked body/casing, or deteriorated shaft seals or pump face seals; resolve according to the specific issue by replacing the damaged parts. 

Water pump maintenance methods
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.
6. Build a roof to shield it from sun and rain for a longer service life.

Applications
- Suitable for 2-3 story detached houses
- Multiple outlets in simultaneous use, such as showers, washing machines, and kitchen sinks
- Can connect to a water storage tank or draw water from a well
- Compatible with tap water and groundwater systems (at an appropriate water level)