Thread: Bosch Dishwasher Circulation & Drain Pump Replacement

So we've had this Bosch Dishwasher for almost 25 years. I've replaced Basket rollers and once the Main Control board.



Needless to say nothing runs forever. Well the Circulation Pump has failed so I ordered a new one along with a replacement Drain Pump, Water Inlet Valve, and a Float Valve from the Bosch Store on Amazon.



Like most Dishwashers you need to disconnect the AC power, Inlet Water, and the Drain Hose as well as a couple of screws holding the Dishwasher to the Cabinet.



Once it's free of the Cabinet I rolled it outside because it still had water in it.



You got to skin them out, the front outside cover and 2 side covers. A cover under the door which that main wiring harness clips into.



By removing the screws holding the Sump section in place inside and removing the 4 screws holding the Base to the Tub the Sump can be slid out from it's location for servicing. Since it is a friction fit on the seal I polished all the hard water, crud, and debris off the Tub Ring Base to ensure a good seal going back.



The drain Pump just rotates out of the Sump Housing and hangs out of the way for replacement. Just unplug the wires and plug in the new Pump assembly.



The Circulation Pump rotates into the two rubber seal sockets and is clamped on one side.



I used a marine Worm Screw Hose Clamp going back by noticed a problem, the Worm Screw Housing was interfering with the Circ Pump housing so I rotated it up out of the way enough that when it was tightened it would not walk back in contack with the Circ Pump. A 8mm Gear Wrench was used for tightening due to the starting location of the Worm Screw.



You just set the old circulation Pump motor next to the new one and swap one wire at a time till the old pump is free.



here are better pictures of the tub Sealing area & seal. I polished the Tub Ring till completely clean and ready for assembly.



Here I'm replacing the old Water Inlet Valve with a new OEM unit.



A last survey of the front assembly before putting the door back together.



On each side of the door that little white clip is attached to a cord that is attached to a spring. This assists the raising and lowering of the door. You can't forget those.



All back together and installed. I turn on the power, set a Rinse & Hold cycle to test it, close the door, and the Circulation Pump motor just Hums. I just can't type how I felt.

Today I received a Float Switch Envelop from the Bosch Store on Amazon well it was a empty envelop, NOT Even SEALED. They mailed me a empty envelop! If that is not enough the new Circulation Pump I just installed is almost locked up. I completely removed the Dishwasher, Pulled the Circulation Pump out and looked at the Impeller thru the Intake Port. Well it's SMASHED inside. A closer look at the Pump Housing and whoever assembled it couldn't even get the Housing completely lock in. I didn't look at it that close, I cut the box open, removed a new pump, and carefully installed it.

My Wife wanted a new Bosch Dishwasher until I put thought in her head; Whoever assembled this pump is assembling new Bosch Dishwashers! If this is how far Bosch has Fallen it's no wonder Germany's manufacturing is in the Toilet. German Craftsman have lost their way.

Anyway I had to order and pay for another pump while the return is processed on the defective one. We are going another 5 days without a dishwasher due to poor quality control at Bosch.

Any of you in the family here that do service work I feel your pain as I get about 75-80% of the parts I need in the first attempt. The rest have to be sent back.

JigRig, the driveshaft for my Mercedes arrived off Ebay. The Universal Joint was so bad I can't believe they shipped it. I returned it today, EBay covered my purchase 100% because I never send stuff back I buy off EBay. A new Driveshaft is on the way, one that has a serviceable U-Joint and Hanger Bearing.

Well Amazon finally got the replacement Circulating Pump out to me yesterday. The defective one originally shipped they gave me credit very quickly. I installed the new Circulating Pump, slid the Dishwasher back in it's place, and did a test run. No Water. None, I'm scratching my head was the new Water Inlet Valve defective too? Pulling the Dishwasher out once again I unplugged the wires to the Valve and inserted the Fluke Multimeter leads before turning the unit back on. 50 VAC was all I had. followed the wiring diagram out to find the Main Control board was not calling for Fill water.

The Dishwasher was turned off by my Wife when the initial failure happened. This is a Bosch Dishwasher. Well the Control Board logged a Fault and until it was cleared the dishwasher refused to operate.

By holding down 2 of the 3 wash cycle buttons then pressing the Main Power Switch I was able to enter Service Mode. After getting the unit into service mode I entered Consumer Test Run Program. Running the full Consumer Test Cycle the Washer cleared the fault and now runs fine.

Moral of the story, if you have a Bosch Dishwasher and it seems to have a problem make sure a Fault code is not Latched. Different models you handle this differently but many of them you just hold down the Main On Switch for 4-5 seconds to clear.

Our old Bosch dishwasher died but it was so old parts were not available damm it.

Originally Posted by Bricks

Our old Bosch dishwasher died but it was so old parts were not available damm it.

Sorry to hear that. Now the issue with Bosch is getting to the proper schematics as there lots of distributors with non-current parts it's just a trick to find them. With the quality so poor in todays manufacturing as long as I can fix something it's getting fixed.

You do it all Roj, but of course we all knew that!