Hotpoint Washer Water Inlet Valve Buzzing or Humming... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) sends 120V AC to the water inlet valve solenoids to open them and allow water to flow into the washer. The MCU uses triacs to switch the voltage on and off. The valve solenoids have a specific resistance value. If the MCU senses an improper resistance, or if the triac shorts, it can cause the valve to buzz or hum, or not operate at all. Voltage paths run through wiring harnesses which can corrode, short, or open circuit.

Symptoms:

The homeowner reports a buzzing or humming noise coming from the back of the Hotpoint washing machine, near where the water hoses connect. The washer may or may not be filling with water. The noise is usually most noticeable during the fill cycle.

Possible Causes:

Partially clogged water inlet screens
Low water pressure to the washing machine
Faulty water inlet valve solenoid
Defective MCU (Main Control Unit) triac controlling the valve
Wiring harness issue to the valve
Grounding issue within the washer chassis

Solution:

1

Disconnect power to the washer at the breaker panel.
2

Turn off the hot and cold water supply valves to the washer.
3

Disconnect the water supply hoses from the back of the washer. Inspect the inlet screens for debris; clean or replace as needed.
4

Reconnect the water supply hoses and turn the water supply back on. Check the water pressure – it should be at least 20 PSI.
5

Disconnect the wire harness from the water inlet valve. Using a multimeter, test the resistance of the valve solenoids. Typical resistance is between 500-1500 ohms. An open or shorted solenoid indicates a faulty valve.
6

If the solenoids test good, reconnect the wire harness. Restore power to the washer at the breaker panel. With the washer in a fill cycle, use a multimeter to check for 120V AC at the water inlet valve terminals. If voltage is present but the valve is buzzing and not opening, replace the water inlet valve.
7

If no voltage is present, suspect a faulty MCU. Further diagnosis of the MCU will require the service manual and advanced troubleshooting skills.

Safety Warning:

Disconnect power to the appliance at the breaker panel before performing any repairs (Lock Out/Tag Out procedure). High voltage is present when the appliance is operating.

Prevention:

Regularly inspect and clean the water inlet screens every 6 months. Ensure adequate water pressure (above 20 PSI) to the washer. Use a water softener if you have hard water.

Expert Tip:

Many Hotpoint washers have a diagnostic mode. Press and hold the Start/Pause button for 3 seconds, then press the Power button twice in rapid succession. This may display error codes that can help pinpoint the issue.

Frequently Asked Questions

•What is the proper way to measure water pressure to the washer?

You can use a water pressure gauge attached to the hose bib where the washer connects. Attach the gauge, turn on the water supply valve fully, and read the pressure on the gauge. It should be at least 20 PSI.

•How do I know if the MCU is actually sending voltage to the valve?

Use a multimeter set to AC voltage. Place one probe on each of the valve terminals where the wire harness connects, *with the wire harness plugged in*. Select a wash cycle that includes a fill cycle and start the washer. The meter should read approximately 120V AC when the fill cycle is active.

•Where can I find the water inlet valve replacement part number?

The part number can be found on a sticker or label on the valve itself. You can also locate it using the washer's model number on the manufacturer's website or a parts supplier website.

Hotpoint Washer Water Inlet Valve Buzzing or Humming Noise: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the proper way to measure water pressure to the washer?

•How do I know if the MCU is actually sending voltage to the valve?

•Where can I find the water inlet valve replacement part number?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: