Midea MWH-38P3, Instruction Manual

4.1 Operating Of The Unit

4.2 Leakage Testing

4.3 To Adjust Water Flow

Switch on the power supply, the unit will take self-inspection for 2s, “ELCB” green 

indicator light will be on (under the condition of no electricity leakage). When the 

water flow exceeds 1.2L/min,  rotate the knob clockwise to switch on heating 

power rotate switch, heating indicator light will be on, the unit start to work.

4. METHODS OF USING

When the water heater is working normally (including working state of PUMP), 

press “TEST” button, if the leakage test circuit is no problem, “ELCB” green 

indicator light will be off, and the unit will not heat. Press “RESET”, testing will 

be canceled, and “ELCB” green indicator light will be on, the unit will be back 

to working state set before. If the circuit leaks, press “RESET” button can’t 

cancel leakagetesting, “EARTH”

、

“ELCB” and “POWER” indicator light is 

twinkling flicker, it means the water heater has problems and can’t be used; all 

the buttons are invalid,  heating is stopped, and pump will be closed. 

Rotate the handle of water flow adjusting valve to adjust the water flow.

4.4 Electricity Leakage Protection

When the electricity leakage testing circuit is working normally, if the leakage current is bigger 

than certain value between 7.5mA and 15mA, “EARTH”

、

“ELCB” and “POWER” indicator light 

will be twinkling flicker, no heating; it can only be used after the failure is excluded. (When 

electricity leakage is tested, red and green indicator lights are all off, stop heating and close the 

pump system.)

3.5 Power Supply Connection

3.6 Water Supply

①
②
③

Choose air switch with leakage protection according to power of water heater;
When connecting the water heater to electric network, please pay attention to connect live 

line (red/brown), neutral line (blue) and earth line (yellow/green) with corresponding line in 

electric network.

Adjust power selection knob to“OFF”;

NOTE

Water flow adjusting valve with filter must be  used when install the unit. Blue marker 

stands for water inlet, red marker stands for water outlet. Do not overexert to avoid 

damaging the water heater.

NOTE

A private power cord should be used for this unit. After connecting to electric network, 

please check the earth condition and make sure the earth resistance is <4Ω.

After all the plumbing is 

finished 

connecting, open water inlet valve of the product and supply 

water to the unit to drain away air inside until there is stable water flow comes out from shower 

head. Check whether there is leakage at joints or not. If there is, check whether the connecting 

parts are fastened or not, then re-supply water.

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