A while back we had a customer with a Miele G863 SCVI Plus dishwasher experiencing a problem we hadn’t encountered before.
Their complaint was the bottom rack was not cleaning. I found the lower spray arm not turning at all. The spray arm was not clogged, the filters were not clogged. This model has a “top solo” option which blocks the water to the lower spray arm, allowing only the upper spray arms to operate. There is a “top solo” valve (TSV) which is used to accomplish this. It is an electromagnet that releases a ball into the water path which is held against the TSV outlet by the water pressure coming out of the circ pump. I found nothing blocking or clogging the TSV. I found the ball within the valve loose. I found 120VAC to the valve, momentarily, only when the “top solo” option was selected. I found resistance through the valve circuit, Miele does not offer specs for that.
So, to be sure I was diagnosing correctly I called Miele tech support. The first tech essentially told me just replace the TSV, that it couldn’t be tested. I called back after leaving the house, the second tech told me it’s testable through a component test (which is true). He also said that the ball should only be free when power is applied, that without power it should be held in place by the TSV solenoid. He also said that the TSV should read infinite ohms when not powered. Only part of that made sense to me so I double checked the schematic, it looks like the TSV circuit should never be “open”, but the voltage supply is switched by the electronic. So I think he was incorrect about reading infinite ohms without power applied. It does make sense that the ball should only be free when top solo is selected, but I’m not certain that power needs to be applied to release the ball or if power should be applied to hold the ball. Based on the voltage readings I think it’s likely true that voltage is applied to release the ball, because I found 120VAC to the valve for just a moment once the circulation pump started running (with top solo option selected), which leads me to believe that the TSV is powered for just long enough to release the ball once there is enough water pressure to hold it against the TSV outlet. See schematic with line and neutral traced to the TSV and the Miele technical description of the TSV below.
So, the top solo valve (Part number 5268871) resolved the issue. By the way, although it’s called a top solo valve everywhere in the tech literature, Miele’s parts department wants to call it a circulation valve.
In any case, the first image is the new top solo valve in the normal position, ie top solo option not selected. The plunger holds the ball in place allowing water to flow through to the lower spray arm (0.68K ohms through the solenoid). The second image is the old, broken TSV, showing the ball out of place, which is also where the ball would be if top solo was selected, blocking the water path to the lower spray arm, held in place by pressure out of the circulation pump. That is the correct orientation of the TSV, it looks like the ball simply falls back into place on the bottom once the water pressure has been reduced, allowing the plunger to hold it again. And the third image is the broken TSV disassembled. The plunger is broken, that collar should be against the casing. The resistance is good though, 0.675K ohms.
So, RD Appliance Service, Corp. successfully diagnosed and repaired another unusual problem with a Miele appliance. If you need a Miele appliance repair call us now at 516-561-0523 or click the red button on the left to book online.
RD Appliance Service, Corp.
Serving Nassau County, Long Island since 1963