One of the worst situations other than a leak that you might have with your washing machine is when you have a full load of clothes in it and it won’t drain the water out. There are a few different problems that can cause this and normally the problem is pretty easy to diagnose.
The first thing you want to do is check the water supply line to the washing machine and look for obstructions. Many machines will have a small collection / filter area just before the pump that you can open and sometimes small objects or more often lint gets stuck in there and causes you problems. When checking for problems you might also need to remove the pump to look inside the input and exit tubes where the hoses connect. However the pump might be clogged internally and some pumps have transparent housings allowing you to see inside to some extent. You can see in the first image the pump has a front screw on opening to inspect for clogs and the two hose connections that must be checked.
The next problem might have to do with the electrical signal getting to the pump to start it. When the washer switches into empty mode two things happen. The front door switch on front loading washers should lock the door and on top loading washers there is a switch that stops the washer when you open it. If these switches are bad it is possible that the pump will never start because of the safety mechanisms. To test this you can use a multi-meter to see if power is getting to the pump. You can also test the switch with the washer unplugged take the connector off the door switch and use your Ohm meter. The ohm setting should be zero when the switch is open and infinity or a high number when it is closed. Press the switch with the ohm meter attached and it should change. If it doesn’t then you know the switch is bad and needs to be replaced.
The Pump might be bad. If you checked that the pump is not clogged, the feed lines and waste lines aren’t clogged and it doesn’t appear to be damaged then you can check the pump with a volt meter. Set your volt meter to Ohms and read the directions with your volt meter. You want to check for continuity and you want there to be a connection across the positive and negative posts on the pump. If the pump is showing no continuity or connection then the pump is bad and needs to be replaced.
Inspecting A Belt Driven Washing Machine Pump
The above diagnosis was related to washing machines that have a pump that has an integrated motor. If you have a pump that is driven by a belt you should follow the steps to check for a clog but obviously you can’t check the motor on the pump. You should inspect the belt for wear or looseness.
Normally when a belt is going bad you could hear a squeaking noise but you can’t always tell by this. The best way is to take the front cover off the washer and lean it back so you can get to the belts below. Find the belt that goes from the washer motor to the pump and squeeze the two sides of the belt together. There should be play in the belt and what you are looking for is movement of the motor. When you squeeze the belt together the motor should move when you get to about 1/4 inch of space between the two sides of the belt. There is an adjustment on the pump by loosening its bolts but not removing them you can slide the pump to the side to make the belt tighter or looser.
You should check for play in the shaft that drives the pump there shouldn’t be any noticeable play or rocking in the shaft and for any leaking from the pump.
Replace the pump if necessary. Also check your safety switches like you would for a front loader.
Final Note
Washing machine pumps are not really expensive. You can get the pump whether it is electric motor driven or belt driven for about $30 from most supply places.
If your pump belt goes bad you might as well replace your drive belt at the same time. They normally run about $15 each.
The hardest part about this job will be leaning the washer back if you need to replace a belt or belt driven pump. It is a job that most people can accomplish in an afternoon with basic tools like a screwdriver and socket set.