Dishwasher help. - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: April 23, 2020, 02:46:44 pm
content: My dishwasher packed up. Beeping constantly. Fault code turns out to be "Optical Water level sensor failure".Googling determines it doesn't have an optical water sensor but a diaphragm based one. I got said sensor out of the machine and tested with a meter.It has three pins. There is a short between two of them and 6 Meg between the others. If I blow into the sensor (after cleaning with boiling water) The pins reverse, the shorted pins open to MegaOhm the Meg pins short.To me that says it working.Put it back in and same thing. Starts filling, about to start the wash and then beeps constantly and empties, same "code 11" fault.It's a Whirlpool DWH B10, no idea how old as it was here when I moved in a last summer.When I was moving it around rocking it to get it out of the cabinet, I tried it and it ran. Once. I reset it and it failed again, so something intermittent and not that sensor... unless I tested it wrong.

author: paulca
author_rank: Super Contributor
timestamp: April 23, 2020, 03:31:20 pm
content: Checked online with Whirlpool/hotpoint and it's apparently 11 years since manufacture. They want a one off £135 to repair it. A new one is £300.Time to get the credit card out and find out if anyone delivers in current climes.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: April 23, 2020, 03:54:04 pm
content: https://www.ukwhitegoods.co.uk/forums/forum/public-support-forums/help-and-support/dishwasher-help-forum/21363-whirlpool-dwh-b10-fault-11-blinksQuite interesting?

author: paulca
author_rank: Super Contributor
timestamp: April 23, 2020, 04:29:47 pm
content: Yea went through that one. Pulled the water sensor. No overflow in the base. The base water float switch appears functional.I think after 11 years it's time it went to the landfill in the sky.Listing to the washer it sounds like it's unable to pick water up from the sump, there is the sound of a pump gasping and spinning unloaded.But I ordered a new one to exercise the credit card.

author: Ralph S.
author_rank: Newbie
timestamp: April 23, 2020, 06:15:13 pm
content: I think I've had a similar problem in a Samsung dishwasher. It didn't heat the water and the display returned a low temperature error. I took it all apart, tested the heater, desoldered and checked the relays - it was a PITA to pick the gel off the PCB. The relay coil circuit went through a pressure sensor made of a diaphragm and a micro switch. All of these things seemed OK, but then it struck me. The washing machine must be sure that the heater is filled with water and there is sufficient flow - that's why there is a pressure sensor at the heater inlet. The real problem was the PUMP! Of course, I've checked it before - it ran (kind of), but not good enough. It had a shorted winding, or something - it ran too slow to build up required pressure, and it got hot after 30s. The heater was disabled by the micro switch in the pressure sensor. I've replaced the pump and now it runs well.

author: james_s
author_rank: Super Contributor
timestamp: April 23, 2020, 09:26:14 pm
content: Dishwasher pumps can have some odd failures. I worked on a Bosch dishwasher my friend had that had low pressure and wasn't cleaning, the pump was running and moving water but it wasn't producing much pressure. Eventually I took it apart and found that the impeller had started to disintegrate, the disc was spinning but the vanes were crumbling and it was coming apart. It moved some water by centrifugal force but not nearly as much as it was meant to.

author: jmelson
author_rank: Super Contributor
timestamp: April 24, 2020, 01:02:36 am
content: Quote from: paulca on April 23, 2020, 02:46:44 pmTake the door apart and inspect the computer board (usually behind the buttons/lights in the door).These get massively exposed to steam during the dry cycle, and get corrosion and conductive contaminationon the board. They can often be fixed by cleaning with alcohol and a toothbrush, and then left to dry for 8hours or so.Mahe sure any shields or covers are fitted back properly as these are needed to partially protect the electronicsfrom the steam bath.We have also had insects nesting inside the electronics, as it stays slightly warm all the time.Jon

author: tom66
author_rank: Super Contributor
timestamp: April 24, 2020, 08:05:39 am
content: I had a similar issue after we foolishly moved our Bosch dishwasher without draining it. Some water went into the back overflow of the machine, and the anti-flood sensor (presumably designed to stop you flooding your kitchen) triggered. Tipping the machine the other way and draining it out, then letting it dry for a few hours, resolved the issue.