Water is filling up in drum when machine is not in use.

Hi.
Replace the watervalve.
Its stuck open

Water valve on washer bad

Is the machine siphoning off water as it fills? If it is check the height of the drain hose and make sure it is above the height of the normal level of water that would be in te drum when washing, if the hose is to low the drum will siphon off the water on its own and continue to fill. If the machine is not siphoning off water while filling then you may have a blocked pressure hose or the pressure hose bottle may be blocked not allowing the pressure switch to activate. there may even be a small hole in the pressure switch hose. Check the thin pressure hose that goes from the bottom of the drum to the pressure switch.

Can you turn off water to machine? The water seleniod needs to be replaced this lets water in the switch sounds like it's stuck open.

replace mixer valve

its the problem of drum getting blocked by any clothes getting tucked up.also try to move the drum manually with the machine off.if it makes any noise its the faulty motor.or drum has lost its alignment.it needs to be reseated properly in that case. -------------- The water fill valve - The water fill valve is a mechanical and electrical part, the coils on the valve need electricity to mechanically open the valve to allow the water to flow into the washer....myth....the washer pumps water into itself...no, it does not. The fill valve opens and the house water pressure pushes the water into the washing machine.
No cold water or no hot water - The fill valve has two coils, one for the hot water and one for the cold water. It is possible that one of the coils can fail and you loose that filling ability. If the cold water coil quits, the hot will still work and during warm fill you will get hot water only and during a cold fill you will get no water at all. If the hot coils quits, you will still have cold water fill, cold water only on a warm setting and no water on a hot fill setting. You can No cold water or no hot water - The fill valve has two coils, one for the hot water and one for the cold water. It is possible that one of the coils can fail and you loose that filling ability. If the cold water coil quits, the hot will still work and during warm fill you will get hot water only and during a cold fill you will get no water at all. If the hot coils quits, you will still have cold water fill, cold water only on a warm setting and no water on a hot fill setting. You can test a fill valve live for 120 volts, power to a fill valve coil and no fill = a bad fill valve. You can also test the coils for continuity, no continuity = a bad fill valve. Some Maytag washers have a fuse in the fill valve circuit, if this fuse let go the washer will not fill. Fill valves can also from time to time stick open and not stop filling. If you have to shut off the fill valves to stop the water from filling in the washer, you have a bad fill valve and you will have to replace it.

Normally I would think that the problem is with the drain system (faulty pump or clogged lines), but you told me that also "When the washing machine is not bein.g used the drum slowly starts to fill with water!!" therefor I think it can be a dafective inlet valve or a faulty control assembly.
In either case, you will need a technician to fix this.

this is 1 of 2 solutions  2 this problem the first thing to check is the vacuum system or it is a split in the pressure switch hose 

You could have a hole in the pump. Check to see where the water is coming from after removing the cabinet, or tip the machine back.

only source is leaking inlet valves and only way to cure is to replace