lg mw2455hw - hot water doesn't stop running, foods washer

[mattd]

Novice trying to troubleshoot a washer problem. I have an LG MW2455HW front load washer, circa 2007. Bought it off craigslist about 4 years ago. It's still in good shape and we haven't had any issues with it until recently.

I noticed there was water in the detergent tray after washes and water around the base of the machine near the back. I pulled the top and noticed the hot water inlet valve appeared corroded and leaking. We moved to OK about 6 months ago, not sure if the hard water/hot water combination does anything. Either way, I ordered a new inlet valve and installed it. Everything looked good, I started up a test Speed Wash cycle on hot/cold. Everything was going fine until I noticed water gushing out of the drain vent that goes from the top of the tub out the back of the machine. I then realized the hot water had not stopped running during the entire cycle - like the valve was stuck open. I turned off the hot water at the source and drained the tub on Spin/Drain mode.

I tried a Spin/Drain cycle with the hot water source on and the same thing happened. The hot water started running and didn't stop. I tried another Speed Wash cycle and the same thing again. The only way to get it to stop is to turn off the water source. Pausing, or even powering off doesn't make the hot water stop. Unplugging the machine, or unplugging the wire from the hot water inlet valve will stop the hot water. I thought maybe it was a bad part, so I ordered another hot water inlet valve. Nope, same results. I reinstalled the original inlet valve, same results. Does not happen on a cold water cycle, it runs completely normal - the cold water will turn off at the appropriate time, etc.

My simple conclusion is that it must be something electrical - main control board? Basically, the valve seems to be getting a signal to open, but never gets a signal to close. Is there any way to further isolate/diagnose this problem? I am assuming I might just have to try another control board...

Thanks.

[Samurai Appliance Repair Man]

On February 6, 2016 at 2:56 PM, mattd said:

Unplugging the machine, or unplugging the wire from the hot water inlet valve will stop the hot water.

This is a bad water inlet valve.

And you posted a bad model number. 

[darren412]

Samurai  are you coming to the conclusion that the water valve is bad because it must be closing and opening intermittently  ?   Is the procedure that we are missing here supposed to be that the water valve should be tested for voltage during the moment the control board is supposed to energize and de energize the valve  and then it can be determined through the voltage readings and the flow of water to conclude the water valve is bad .    I do understand that most of the time during an overflow situation that if you shut the water supply off and it stops the water flow that it usually means the valve is bad.

[Samurai Appliance Repair Man]

I actually read that wrong- had somehow read a "NOT shut off water..." Old eyes, small phone. 

The valve must still be getting voltage. 

Still a bad model number. Unless I'm not seeing that right, either! 

[darren412]

Matt You need to first respond with the correct model number to begin with.  I believe your model # is WM2455HW     With out the proper model and serial numbers given first at the beginning of your questions  it will make it very difficult for you to get the correct answers to your questions in a timely manner if you need them.  I am definately not one of them but there are some real good techs on this site that are very helpful and informative when it comes to needing help with an appliance and they cant properly assist you in a timely fashion without the correct Model #'s for the appliances.  run a diagnostic test cycle and do a component test . That is one simple way to help you to identify if you have a water inlet valve problem.  There is a hot and cold water valve test in that procedure so you can  put a meter on the hot water inlet valve during the test. This way when the board is suppose to energize and de energizes  the hot water valve during the test .  That should tell you if the control board keeps giving it voltage during the test sequence when it shouldn't  be.  You can also just run a speed wash cyle and test the hot water valve the same way during the speed wash cycle process with your meter. You will know in the first 5 minutes with your meter whats going on with the hot water valve and its energizing process with the control board. Its sounds as though the water pressure valve is ok since in your question you mentioned the washer works fine in the cold water wash cycle.

[mattd]

Sorry, you are right, the model number is WM2455HW. I mixed up the first 2 letters. Any more info you would need? Serial numbers?

If the board keeps giving the hot water valve voltage does that mean a bad board? Or something else? I've tried replacing the hot water valve 2x, but get the same result. I assume I don't keep getting bad parts...

[Budget Appliance Repair]

Yes, usually that would mean a bad board.  Most newer appliances that use a computer board switch neutral on/off with a triac to operate loads and each load is constantly supplied with 110Vac.  If a triac for a load such as a water valve or pump shorts out it will run that load constantly if the machine is plugged in.