Ronnie S. for Model Number LDF7551ST I have an OE code which is a drain issue. I've checked the drain pump and no blockages and it runs when removed from the dishwasher. If I blow into the drain tube at the pump end it is blocked unless I press the 'needle valve' down (this is located on the left-hand side of the unit where the pump tube and sink tube are connected by a 'U' tube. This 'U' tube is not shown on any drawings here but it has a small black tube that connects to F040). Similarly, if I blow into the tube at the sink end it is blocked unless the needle valve is pressed down. My question is what does this needle valve do and how does it work? If this is faulty could that be causing my OE drain issue as no tubes are kinked or flattened and there are no objects lodged anywhere? When the dishwasher is draining the pump will only run for a few seconds and only about 5 oz. of water is pumped out.
Answer Hello Ronnie, You will need to verify that the diverter motor is good and is able to switch the diverter valve from water circulation to drain. If something is blocking the diverter valve, the motor will not be strong enough to force the movement of the valve. Also, to check for a restriction/clog in the drain line you would need to disconnect the drain from the dishwasher and blow through it toward the sink drain since there is normally a check valve in the drain line designed to prevent sink waters' entry into the dishwasher. You should also check for plastic, (like they use to wrap individually wrapped cheese), around the pump impeller or elsewhere in the dishwasher, clogged filters, and check that the drain pump impeller has not separated from the drain pump motor shaft. Let us know if further assistance is needed. Read More... Answered by AppliancePartsPros.com | Friday, July 20, 2018